[PATCH v3 0/3] Refactor xhci quirks and plat private data

[PATCH v3 0/3] Refactor xhci quirks and plat private data

[Sandeep Maheswaram]

changes in v3:
Updated the commit description for PATCH 2/3 and PATCH 3/3. 

changes in v2:
Added a PATCH 2/3 to remove unwanted header inclusion.
Fixed minor nitpicks in PATCH 3/3.

Pavankumar Kondeti (1):
  usb: xhci: refactor quirks and plat private data

Sandeep Maheswaram (2):
  usb: xhci: Remove unwanted header inclusion
  usb: dwc: host: add xhci_plat_priv quirk XHCI_SKIP_PHY_INIT

 drivers/usb/cdns3/host.c        |  2 +-
 drivers/usb/dwc3/host.c         | 13 ++++++++
 drivers/usb/host/xhci-plat.c    |  3 +-
 drivers/usb/host/xhci-plat.h    | 24 ---------------
 drivers/usb/host/xhci-rcar.c    |  3 +-
 drivers/usb/host/xhci.h         | 60 ++++--------------------------------
 include/linux/usb/xhci-plat.h   | 24 +++++++++++++++
 include/linux/usb/xhci-quirks.h | 67 +++++++++++++++++++++++++++++++++++++++++
 8 files changed, 115 insertions(+), 81 deletions(-)
 delete mode 100644 drivers/usb/host/xhci-plat.h
 create mode 100644 include/linux/usb/xhci-plat.h
 create mode 100644 include/linux/usb/xhci-quirks.h

-- 
2.7.4

[PATCH v3 1/3] usb: xhci: refactor quirks and plat private data

[Sandeep Maheswaram]

From: Pavankumar Kondeti <quic_pkondeti@quicinc.com>

This refactoring allows drivers like dwc3 host glue driver to
specify their xhci quirks.

Signed-off-by: Pavankumar Kondeti <quic_pkondeti@quicinc.com>
Signed-off-by: Sandeep Maheswaram <quic_c_sanm@quicinc.com>
---
 drivers/usb/cdns3/host.c        |  2 +-
 drivers/usb/host/xhci-plat.c    |  3 +-
 drivers/usb/host/xhci-plat.h    | 24 ---------------
 drivers/usb/host/xhci-rcar.c    |  3 +-
 drivers/usb/host/xhci.h         | 60 ++++--------------------------------
 include/linux/usb/xhci-plat.h   | 23 ++++++++++++++
 include/linux/usb/xhci-quirks.h | 67 +++++++++++++++++++++++++++++++++++++++++
 7 files changed, 101 insertions(+), 81 deletions(-)
 delete mode 100644 drivers/usb/host/xhci-plat.h
 create mode 100644 include/linux/usb/xhci-plat.h
 create mode 100644 include/linux/usb/xhci-quirks.h

diff --git a/drivers/usb/cdns3/host.c b/drivers/usb/cdns3/host.c
index 9643b90..7fb8049 100644
--- a/drivers/usb/cdns3/host.c
+++ b/drivers/usb/cdns3/host.c
@@ -15,8 +15,8 @@
 #include "drd.h"
 #include "host-export.h"
 #include <linux/usb/hcd.h>
+#include <linux/usb/xhci-plat.h>
 #include "../host/xhci.h"
-#include "../host/xhci-plat.h"
 
 #define XECP_PORT_CAP_REG	0x8000
 #define XECP_AUX_CTRL_REG1	0x8120
diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
index 649ffd8..601e656 100644
--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -19,9 +19,10 @@
 #include <linux/slab.h>
 #include <linux/acpi.h>
 #include <linux/usb/of.h>
+#include <linux/usb/xhci-quirks.h>
+#include <linux/usb/xhci-plat.h>
 
 #include "xhci.h"
-#include "xhci-plat.h"
 #include "xhci-mvebu.h"
 #include "xhci-rcar.h"
 
diff --git a/drivers/usb/host/xhci-plat.h b/drivers/usb/host/xhci-plat.h
deleted file mode 100644
index 1fb149d..0000000
--- a/drivers/usb/host/xhci-plat.h
+++ /dev/null
@@ -1,24 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/*
- * xhci-plat.h - xHCI host controller driver platform Bus Glue.
- *
- * Copyright (C) 2015 Renesas Electronics Corporation
- */
-
-#ifndef _XHCI_PLAT_H
-#define _XHCI_PLAT_H
-
-#include "xhci.h"	/* for hcd_to_xhci() */
-
-struct xhci_plat_priv {
-	const char *firmware_name;
-	unsigned long long quirks;
-	void (*plat_start)(struct usb_hcd *);
-	int (*init_quirk)(struct usb_hcd *);
-	int (*suspend_quirk)(struct usb_hcd *);
-	int (*resume_quirk)(struct usb_hcd *);
-};
-
-#define hcd_to_xhci_priv(h) ((struct xhci_plat_priv *)hcd_to_xhci(h)->priv)
-#define xhci_to_priv(x) ((struct xhci_plat_priv *)(x)->priv)
-#endif	/* _XHCI_PLAT_H */
diff --git a/drivers/usb/host/xhci-rcar.c b/drivers/usb/host/xhci-rcar.c
index aef0258..18d3272 100644
--- a/drivers/usb/host/xhci-rcar.c
+++ b/drivers/usb/host/xhci-rcar.c
@@ -12,9 +12,10 @@
 #include <linux/of.h>
 #include <linux/usb/phy.h>
 #include <linux/sys_soc.h>
+#include <linux/usb/xhci-quirks.h>
+#include <linux/usb/xhci-plat.h>
 
 #include "xhci.h"
-#include "xhci-plat.h"
 #include "xhci-rcar.h"
 
 /*
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 473a33c..ae400da 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -17,6 +17,8 @@
 #include <linux/kernel.h>
 #include <linux/usb/hcd.h>
 #include <linux/io-64-nonatomic-lo-hi.h>
+#include <linux/usb/xhci-quirks.h>
+#include <linux/usb/xhci-plat.h>
 
 /* Code sharing between pci-quirks and xhci hcd */
 #include	"xhci-ext-caps.h"
@@ -1847,60 +1849,6 @@ struct xhci_hcd {
 #define XHCI_STATE_HALTED	(1 << 1)
 #define XHCI_STATE_REMOVING	(1 << 2)
 	unsigned long long	quirks;
-#define	XHCI_LINK_TRB_QUIRK	BIT_ULL(0)
-#define XHCI_RESET_EP_QUIRK	BIT_ULL(1)
-#define XHCI_NEC_HOST		BIT_ULL(2)
-#define XHCI_AMD_PLL_FIX	BIT_ULL(3)
-#define XHCI_SPURIOUS_SUCCESS	BIT_ULL(4)
-/*
- * Certain Intel host controllers have a limit to the number of endpoint
- * contexts they can handle.  Ideally, they would signal that they can't handle
- * anymore endpoint contexts by returning a Resource Error for the Configure
- * Endpoint command, but they don't.  Instead they expect software to keep track
- * of the number of active endpoints for them, across configure endpoint
- * commands, reset device commands, disable slot commands, and address device
- * commands.
- */
-#define XHCI_EP_LIMIT_QUIRK	BIT_ULL(5)
-#define XHCI_BROKEN_MSI		BIT_ULL(6)
-#define XHCI_RESET_ON_RESUME	BIT_ULL(7)
-#define	XHCI_SW_BW_CHECKING	BIT_ULL(8)
-#define XHCI_AMD_0x96_HOST	BIT_ULL(9)
-#define XHCI_TRUST_TX_LENGTH	BIT_ULL(10)
-#define XHCI_LPM_SUPPORT	BIT_ULL(11)
-#define XHCI_INTEL_HOST		BIT_ULL(12)
-#define XHCI_SPURIOUS_REBOOT	BIT_ULL(13)
-#define XHCI_COMP_MODE_QUIRK	BIT_ULL(14)
-#define XHCI_AVOID_BEI		BIT_ULL(15)
-#define XHCI_PLAT		BIT_ULL(16)
-#define XHCI_SLOW_SUSPEND	BIT_ULL(17)
-#define XHCI_SPURIOUS_WAKEUP	BIT_ULL(18)
-/* For controllers with a broken beyond repair streams implementation */
-#define XHCI_BROKEN_STREAMS	BIT_ULL(19)
-#define XHCI_PME_STUCK_QUIRK	BIT_ULL(20)
-#define XHCI_MTK_HOST		BIT_ULL(21)
-#define XHCI_SSIC_PORT_UNUSED	BIT_ULL(22)
-#define XHCI_NO_64BIT_SUPPORT	BIT_ULL(23)
-#define XHCI_MISSING_CAS	BIT_ULL(24)
-/* For controller with a broken Port Disable implementation */
-#define XHCI_BROKEN_PORT_PED	BIT_ULL(25)
-#define XHCI_LIMIT_ENDPOINT_INTERVAL_7	BIT_ULL(26)
-#define XHCI_U2_DISABLE_WAKE	BIT_ULL(27)
-#define XHCI_ASMEDIA_MODIFY_FLOWCONTROL	BIT_ULL(28)
-#define XHCI_HW_LPM_DISABLE	BIT_ULL(29)
-#define XHCI_SUSPEND_DELAY	BIT_ULL(30)
-#define XHCI_INTEL_USB_ROLE_SW	BIT_ULL(31)
-#define XHCI_ZERO_64B_REGS	BIT_ULL(32)
-#define XHCI_DEFAULT_PM_RUNTIME_ALLOW	BIT_ULL(33)
-#define XHCI_RESET_PLL_ON_DISCONNECT	BIT_ULL(34)
-#define XHCI_SNPS_BROKEN_SUSPEND    BIT_ULL(35)
-#define XHCI_RENESAS_FW_QUIRK	BIT_ULL(36)
-#define XHCI_SKIP_PHY_INIT	BIT_ULL(37)
-#define XHCI_DISABLE_SPARSE	BIT_ULL(38)
-#define XHCI_SG_TRB_CACHE_SIZE_QUIRK	BIT_ULL(39)
-#define XHCI_NO_SOFT_RETRY	BIT_ULL(40)
-#define XHCI_BROKEN_D3COLD	BIT_ULL(41)
-#define XHCI_EP_CTX_BROKEN_DCS	BIT_ULL(42)
 
 	unsigned int		num_active_eps;
 	unsigned int		limit_active_eps;
@@ -1966,6 +1914,10 @@ static inline struct usb_hcd *xhci_to_hcd(struct xhci_hcd *xhci)
 	return xhci->main_hcd;
 }
 
+/* For xhci-plat drivers */
+#define hcd_to_xhci_priv(h) ((struct xhci_plat_priv *)hcd_to_xhci(h)->priv)
+#define xhci_to_priv(x) ((struct xhci_plat_priv *)(x)->priv)
+
 #define xhci_dbg(xhci, fmt, args...) \
 	dev_dbg(xhci_to_hcd(xhci)->self.controller , fmt , ## args)
 #define xhci_err(xhci, fmt, args...) \
diff --git a/include/linux/usb/xhci-plat.h b/include/linux/usb/xhci-plat.h
new file mode 100644
index 0000000..906e907
--- /dev/null
+++ b/include/linux/usb/xhci-plat.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * xhci-plat.h - xHCI host controller driver platform Bus Glue.
+ *
+ * Copyright (C) 2015 Renesas Electronics Corporation
+ */
+
+#ifndef _XHCI_PLAT_H
+#define _XHCI_PLAT_H
+
+#include <linux/types.h>
+#include <linux/usb/hcd.h>
+
+struct xhci_plat_priv {
+	const char *firmware_name;
+	unsigned long long quirks;
+	void (*plat_start)(struct usb_hcd *hcd);
+	int (*init_quirk)(struct usb_hcd *hcd);
+	int (*suspend_quirk)(struct usb_hcd *hcd);
+	int (*resume_quirk)(struct usb_hcd *hcd);
+};
+
+#endif	/* _XHCI_PLAT_H */
diff --git a/include/linux/usb/xhci-quirks.h b/include/linux/usb/xhci-quirks.h
new file mode 100644
index 0000000..57ae0b1
--- /dev/null
+++ b/include/linux/usb/xhci-quirks.h
@@ -0,0 +1,67 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/*
+ * xHCI host controller driver quirks
+ *
+ * Copyright (C) 2008 Intel Corp.
+ */
+
+#ifndef _XHCI_QUIRKS_H
+#define _XHCI_QUIRKS_H
+
+#define XHCI_LINK_TRB_QUIRK	BIT_ULL(0)
+#define XHCI_RESET_EP_QUIRK	BIT_ULL(1)
+#define XHCI_NEC_HOST		BIT_ULL(2)
+#define XHCI_AMD_PLL_FIX	BIT_ULL(3)
+#define XHCI_SPURIOUS_SUCCESS	BIT_ULL(4)
+/*
+ * Certain Intel host controllers have a limit to the number of endpoint
+ * contexts they can handle.  Ideally, they would signal that they can't handle
+ * anymore endpoint contexts by returning a Resource Error for the Configure
+ * Endpoint command, but they don't.  Instead they expect software to keep track
+ * of the number of active endpoints for them, across configure endpoint
+ * commands, reset device commands, disable slot commands, and address device
+ * commands.
+ */
+#define XHCI_EP_LIMIT_QUIRK	BIT_ULL(5)
+#define XHCI_BROKEN_MSI		BIT_ULL(6)
+#define XHCI_RESET_ON_RESUME	BIT_ULL(7)
+#define XHCI_SW_BW_CHECKING	BIT_ULL(8)
+#define XHCI_AMD_0x96_HOST	BIT_ULL(9)
+#define XHCI_TRUST_TX_LENGTH	BIT_ULL(10)
+#define XHCI_LPM_SUPPORT	BIT_ULL(11)
+#define XHCI_INTEL_HOST		BIT_ULL(12)
+#define XHCI_SPURIOUS_REBOOT	BIT_ULL(13)
+#define XHCI_COMP_MODE_QUIRK	BIT_ULL(14)
+#define XHCI_AVOID_BEI		BIT_ULL(15)
+#define XHCI_PLAT		BIT_ULL(16)
+#define XHCI_SLOW_SUSPEND	BIT_ULL(17)
+#define XHCI_SPURIOUS_WAKEUP	BIT_ULL(18)
+/* For controllers with a broken beyond repair streams implementation */
+#define XHCI_BROKEN_STREAMS	BIT_ULL(19)
+#define XHCI_PME_STUCK_QUIRK	BIT_ULL(20)
+#define XHCI_MTK_HOST		BIT_ULL(21)
+#define XHCI_SSIC_PORT_UNUSED	BIT_ULL(22)
+#define XHCI_NO_64BIT_SUPPORT	BIT_ULL(23)
+#define XHCI_MISSING_CAS	BIT_ULL(24)
+/* For controller with a broken Port Disable implementation */
+#define XHCI_BROKEN_PORT_PED	BIT_ULL(25)
+#define XHCI_LIMIT_ENDPOINT_INTERVAL_7	BIT_ULL(26)
+#define XHCI_U2_DISABLE_WAKE	BIT_ULL(27)
+#define XHCI_ASMEDIA_MODIFY_FLOWCONTROL	BIT_ULL(28)
+#define XHCI_HW_LPM_DISABLE	BIT_ULL(29)
+#define XHCI_SUSPEND_DELAY	BIT_ULL(30)
+#define XHCI_INTEL_USB_ROLE_SW	BIT_ULL(31)
+#define XHCI_ZERO_64B_REGS	BIT_ULL(32)
+#define XHCI_DEFAULT_PM_RUNTIME_ALLOW	BIT_ULL(33)
+#define XHCI_RESET_PLL_ON_DISCONNECT	BIT_ULL(34)
+#define XHCI_SNPS_BROKEN_SUSPEND    BIT_ULL(35)
+#define XHCI_RENESAS_FW_QUIRK	BIT_ULL(36)
+#define XHCI_SKIP_PHY_INIT	BIT_ULL(37)
+#define XHCI_DISABLE_SPARSE	BIT_ULL(38)
+#define XHCI_SG_TRB_CACHE_SIZE_QUIRK	BIT_ULL(39)
+#define XHCI_NO_SOFT_RETRY	BIT_ULL(40)
+#define XHCI_BROKEN_D3COLD	BIT_ULL(41)
+#define XHCI_EP_CTX_BROKEN_DCS	BIT_ULL(42)
+
+#endif /* _XHCI_QUIRKS_H */
-- 
2.7.4

[PATCH v3 2/3] usb: xhci: Remove unwanted header inclusion

[Sandeep Maheswaram]

The header file linux/usb/hcd.h is already included where we are using
xhci-plat.h so remove the header file and forward declare struct usb_hcd
to avoid multiple inclusions.

Signed-off-by: Sandeep Maheswaram <quic_c_sanm@quicinc.com>
---
This patch is to address below comment.
https://patchwork.kernel.org/project/linux-arm-msm/patch/1644949454-814-2-git-send-email-quic_c_sanm@quicinc.com/#24739885

 include/linux/usb/xhci-plat.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/linux/usb/xhci-plat.h b/include/linux/usb/xhci-plat.h
index 906e907..576e400 100644
--- a/include/linux/usb/xhci-plat.h
+++ b/include/linux/usb/xhci-plat.h
@@ -9,7 +9,8 @@
 #define _XHCI_PLAT_H
 
 #include <linux/types.h>
-#include <linux/usb/hcd.h>
+
+struct usb_hcd;
 
 struct xhci_plat_priv {
 	const char *firmware_name;
-- 
2.7.4

[PATCH v3 3/3] usb: dwc: host: add xhci_plat_priv quirk XHCI_SKIP_PHY_INIT

[Sandeep Maheswaram]

Currently the phy init is done from dwc3 and also xhci which makes the
runtime_usage value 2 for the phy which causes issue during runtime
suspend. When we run the below command the runtime_status still shows
active.
echo auto > /sys/bus/platform/devices/88e3000.phy/power/control

dwc3 manages PHY by own DRD driver, so skip the management by
HCD core by setting this quirk.

Signed-off-by: Sandeep Maheswaram <quic_c_sanm@quicinc.com>
---
 drivers/usb/dwc3/host.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/usb/dwc3/host.c b/drivers/usb/dwc3/host.c
index eda8719..d4fcf06 100644
--- a/drivers/usb/dwc3/host.c
+++ b/drivers/usb/dwc3/host.c
@@ -13,6 +13,12 @@
 #include <linux/platform_device.h>
 
 #include "core.h"
+#include <linux/usb/xhci-plat.h>
+#include <linux/usb/xhci-quirks.h>
+
+static const struct xhci_plat_priv xhci_plat_dwc3_xhci = {
+	.quirks = XHCI_SKIP_PHY_INIT,
+};
 
 static void dwc3_host_fill_xhci_irq_res(struct dwc3 *dwc,
 					int irq, char *name)
@@ -122,6 +128,13 @@ int dwc3_host_init(struct dwc3 *dwc)
 		}
 	}
 
+	ret = platform_device_add_data(xhci, &xhci_plat_dwc3_xhci,
+			sizeof(xhci_plat_dwc3_xhci));
+	if (ret) {
+		dev_err(dwc->dev, "failed to add data to xHCI\n");
+		goto err;
+	}
+
 	ret = platform_device_add(xhci);
 	if (ret) {
 		dev_err(dwc->dev, "failed to register xHCI device\n");
-- 
2.7.4

Re: [PATCH v3 3/3] usb: dwc: host: add xhci_plat_priv quirk XHCI_SKIP_PHY_INIT

[Heikki Krogerus]

On Thu, Mar 24, 2022 at 12:07:11PM +0530, Sandeep Maheswaram wrote:
> Currently the phy init is done from dwc3 and also xhci which makes the
> runtime_usage value 2 for the phy which causes issue during runtime
> suspend. When we run the below command the runtime_status still shows
> active.
> echo auto > /sys/bus/platform/devices/88e3000.phy/power/control
> 
> dwc3 manages PHY by own DRD driver, so skip the management by
> HCD core by setting this quirk.
> 
> Signed-off-by: Sandeep Maheswaram <quic_c_sanm@quicinc.com>
> ---
>  drivers/usb/dwc3/host.c | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/drivers/usb/dwc3/host.c b/drivers/usb/dwc3/host.c
> index eda8719..d4fcf06 100644
> --- a/drivers/usb/dwc3/host.c
> +++ b/drivers/usb/dwc3/host.c
> @@ -13,6 +13,12 @@
>  #include <linux/platform_device.h>
>  
>  #include "core.h"
> +#include <linux/usb/xhci-plat.h>
> +#include <linux/usb/xhci-quirks.h>
> +
> +static const struct xhci_plat_priv xhci_plat_dwc3_xhci = {
> +	.quirks = XHCI_SKIP_PHY_INIT,
> +};
>  
>  static void dwc3_host_fill_xhci_irq_res(struct dwc3 *dwc,
>  					int irq, char *name)
> @@ -122,6 +128,13 @@ int dwc3_host_init(struct dwc3 *dwc)
>  		}
>  	}
>  
> +	ret = platform_device_add_data(xhci, &xhci_plat_dwc3_xhci,
> +			sizeof(xhci_plat_dwc3_xhci));
> +	if (ret) {
> +		dev_err(dwc->dev, "failed to add data to xHCI\n");
> +		goto err;
> +	}
> +
>  	ret = platform_device_add(xhci);
>  	if (ret) {
>  		dev_err(dwc->dev, "failed to register xHCI device\n");

I think you should just use device property:

diff --git a/drivers/usb/dwc3/host.c b/drivers/usb/dwc3/host.c
index eda871973d6cc..dbff7b8ed6d5e 100644
--- a/drivers/usb/dwc3/host.c
+++ b/drivers/usb/dwc3/host.c
@@ -67,7 +67,7 @@ static int dwc3_host_get_irq(struct dwc3 *dwc)
 
 int dwc3_host_init(struct dwc3 *dwc)
 {
-       struct property_entry   props[4];
+       struct property_entry   props[5];
        struct platform_device  *xhci;
        int                     ret, irq;
        int                     prop_idx = 0;
@@ -114,12 +114,12 @@ int dwc3_host_init(struct dwc3 *dwc)
        if (DWC3_VER_IS_WITHIN(DWC3, ANY, 300A))
                props[prop_idx++] = PROPERTY_ENTRY_BOOL("quirk-broken-port-ped");
 
-       if (prop_idx) {
-               ret = device_create_managed_software_node(&xhci->dev, props, NULL);
-               if (ret) {
-                       dev_err(dwc->dev, "failed to add properties to xHCI\n");
-                       goto err;
-               }
+       props[prop_idx++] = PROPERTY_ENTRY_BOOL("skip-phy-init");
+
+       ret = device_create_managed_software_node(&xhci->dev, props, NULL);
+       if (ret) {
+               dev_err(dwc->dev, "failed to add properties to xHCI\n");
+               goto err;
        }
 
        ret = platform_device_add(xhci);
diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
index 649ffd861b44e..31ed39d06e29b 100644
--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -307,6 +307,9 @@ static int xhci_plat_probe(struct platform_device *pdev)
 
                device_property_read_u32(tmpdev, "imod-interval-ns",
                                         &xhci->imod_interval);
+
+               if (device_property_read_bool(tmpdev, "skip-phy-init"))
+                       hcd->skip_phy_initialization = 1;
        }
 
        hcd->usb_phy = devm_usb_get_phy_by_phandle(sysdev, "usb-phy", 0);

-- 
heikki

Re: [PATCH v3 3/3] usb: dwc: host: add xhci_plat_priv quirk XHCI_SKIP_PHY_INIT

[Mathias Nyman]

On 24.3.2022 14.27, Heikki Krogerus wrote:
> On Thu, Mar 24, 2022 at 12:07:11PM +0530, Sandeep Maheswaram wrote:
>> Currently the phy init is done from dwc3 and also xhci which makes the
>> runtime_usage value 2 for the phy which causes issue during runtime
>> suspend. When we run the below command the runtime_status still shows
>> active.
>> echo auto > /sys/bus/platform/devices/88e3000.phy/power/control
>>
>> dwc3 manages PHY by own DRD driver, so skip the management by
>> HCD core by setting this quirk.
>>
>> Signed-off-by: Sandeep Maheswaram <quic_c_sanm@quicinc.com>
>> ---
>>  drivers/usb/dwc3/host.c | 13 +++++++++++++
>>  1 file changed, 13 insertions(+)
>>
>> diff --git a/drivers/usb/dwc3/host.c b/drivers/usb/dwc3/host.c
>> index eda8719..d4fcf06 100644
>> --- a/drivers/usb/dwc3/host.c
>> +++ b/drivers/usb/dwc3/host.c
>> @@ -13,6 +13,12 @@
>>  #include <linux/platform_device.h>
>>  
>>  #include "core.h"
>> +#include <linux/usb/xhci-plat.h>
>> +#include <linux/usb/xhci-quirks.h>
>> +
>> +static const struct xhci_plat_priv xhci_plat_dwc3_xhci = {
>> +	.quirks = XHCI_SKIP_PHY_INIT,
>> +};
>>  
>>  static void dwc3_host_fill_xhci_irq_res(struct dwc3 *dwc,
>>  					int irq, char *name)
>> @@ -122,6 +128,13 @@ int dwc3_host_init(struct dwc3 *dwc)
>>  		}
>>  	}
>>  
>> +	ret = platform_device_add_data(xhci, &xhci_plat_dwc3_xhci,
>> +			sizeof(xhci_plat_dwc3_xhci));
>> +	if (ret) {
>> +		dev_err(dwc->dev, "failed to add data to xHCI\n");
>> +		goto err;
>> +	}
>> +
>>  	ret = platform_device_add(xhci);
>>  	if (ret) {
>>  		dev_err(dwc->dev, "failed to register xHCI device\n");
> 
> I think you should just use device property:
> 

This was suggested in an earlier series, but was rejected as it also added
the property as a device tree parameter.

I think adding more device properties can be messy in the long run, especially if we
need to add them for many of the existing xhci quirks.
We also end up with a mix where some device properties are listed as device tree
parameters, and some not.

Defining xhci quirks and platform data structure in headers shared with dwc3 and cdns3
allow those drivers to easily set any existing xhci quirk, or other possible optional
callbacks.

cdns3 driver is already doing this, but it includes the full xhci.h header.
This series cleans up that a bit so cdns3 will only include xhci quirk bits and
platform data structure.

On the downside we add a couple xhci related header files to include/linux/usb/
Let me know if you see any other issues I missed with this approach.

Thanks
Mathias

Re: [PATCH v3 3/3] usb: dwc: host: add xhci_plat_priv quirk XHCI_SKIP_PHY_INIT

[Heikki Krogerus]

On Fri, Mar 25, 2022 at 12:36:22AM +0200, Mathias Nyman wrote:
> On 24.3.2022 14.27, Heikki Krogerus wrote:
> > On Thu, Mar 24, 2022 at 12:07:11PM +0530, Sandeep Maheswaram wrote:
> >> Currently the phy init is done from dwc3 and also xhci which makes the
> >> runtime_usage value 2 for the phy which causes issue during runtime
> >> suspend. When we run the below command the runtime_status still shows
> >> active.
> >> echo auto > /sys/bus/platform/devices/88e3000.phy/power/control
> >>
> >> dwc3 manages PHY by own DRD driver, so skip the management by
> >> HCD core by setting this quirk.
> >>
> >> Signed-off-by: Sandeep Maheswaram <quic_c_sanm@quicinc.com>
> >> ---
> >>  drivers/usb/dwc3/host.c | 13 +++++++++++++
> >>  1 file changed, 13 insertions(+)
> >>
> >> diff --git a/drivers/usb/dwc3/host.c b/drivers/usb/dwc3/host.c
> >> index eda8719..d4fcf06 100644
> >> --- a/drivers/usb/dwc3/host.c
> >> +++ b/drivers/usb/dwc3/host.c
> >> @@ -13,6 +13,12 @@
> >>  #include <linux/platform_device.h>
> >>  
> >>  #include "core.h"
> >> +#include <linux/usb/xhci-plat.h>
> >> +#include <linux/usb/xhci-quirks.h>
> >> +
> >> +static const struct xhci_plat_priv xhci_plat_dwc3_xhci = {
> >> +	.quirks = XHCI_SKIP_PHY_INIT,
> >> +};
> >>  
> >>  static void dwc3_host_fill_xhci_irq_res(struct dwc3 *dwc,
> >>  					int irq, char *name)
> >> @@ -122,6 +128,13 @@ int dwc3_host_init(struct dwc3 *dwc)
> >>  		}
> >>  	}
> >>  
> >> +	ret = platform_device_add_data(xhci, &xhci_plat_dwc3_xhci,
> >> +			sizeof(xhci_plat_dwc3_xhci));
> >> +	if (ret) {
> >> +		dev_err(dwc->dev, "failed to add data to xHCI\n");
> >> +		goto err;
> >> +	}
> >> +
> >>  	ret = platform_device_add(xhci);
> >>  	if (ret) {
> >>  		dev_err(dwc->dev, "failed to register xHCI device\n");
> > 
> > I think you should just use device property:
> > 
> 
> This was suggested in an earlier series, but was rejected as it also added
> the property as a device tree parameter.
> 
> I think adding more device properties can be messy in the long run, especially if we
> need to add them for many of the existing xhci quirks.
> We also end up with a mix where some device properties are listed as device tree
> parameters, and some not.
> 
> Defining xhci quirks and platform data structure in headers shared with dwc3 and cdns3
> allow those drivers to easily set any existing xhci quirk, or other possible optional
> callbacks.
> 
> cdns3 driver is already doing this, but it includes the full xhci.h header.
> This series cleans up that a bit so cdns3 will only include xhci quirk bits and
> platform data structure.
> 
> On the downside we add a couple xhci related header files to include/linux/usb/
> Let me know if you see any other issues I missed with this approach.

The problem here is that these drivers are now coupled together, and
that should not be taken lightly. We have a dependency hell in our
hands with a lot of drivers, and the culprit is always platform data.

Build-in device properties may be messy, but I would still say they
are less messy than those quirk flags - you got to admit, they are a
mess. The benefit from build-in properties is in any case the fact
that they remove the need to couple these drivers together.

You can also use something like naming convention if you are worried
about confusion between devicetree properties and build-in only
properties ("build-in:skip-phy-init" or whatever), and of course
require that each of the build-in only property is documented clearly
in drivers/usb/host/xhci-plat.c. But this in any case really can not
be justification for a platform data blob just so you can avoid using
the properties - honestly, it really should to be the other way
around.

Platform data is in practice always problematic. On top of the driver
coupling, it creates maintenance burden, code duplication, etc. Please
don't just accept it lightly. I'm telling you, for hacks like this, the
build-in device properties is a much much safer bet.

thanks,

-- 
heikki

Re: [PATCH v3 3/3] usb: dwc: host: add xhci_plat_priv quirk XHCI_SKIP_PHY_INIT

[Mathias Nyman]

On 25.3.2022 13.27, Heikki Krogerus wrote:
> On Fri, Mar 25, 2022 at 12:36:22AM +0200, Mathias Nyman wrote:
>> On 24.3.2022 14.27, Heikki Krogerus wrote:
>>> On Thu, Mar 24, 2022 at 12:07:11PM +0530, Sandeep Maheswaram wrote:
>>>> Currently the phy init is done from dwc3 and also xhci which makes the
>>>> runtime_usage value 2 for the phy which causes issue during runtime
>>>> suspend. When we run the below command the runtime_status still shows
>>>> active.
>>>> echo auto > /sys/bus/platform/devices/88e3000.phy/power/control
>>>>
>>>> dwc3 manages PHY by own DRD driver, so skip the management by
>>>> HCD core by setting this quirk.
>>>>
>>>> Signed-off-by: Sandeep Maheswaram <quic_c_sanm@quicinc.com>
>>>> ---
>>>>  drivers/usb/dwc3/host.c | 13 +++++++++++++
>>>>  1 file changed, 13 insertions(+)
>>>>
>>>> diff --git a/drivers/usb/dwc3/host.c b/drivers/usb/dwc3/host.c
>>>> index eda8719..d4fcf06 100644
>>>> --- a/drivers/usb/dwc3/host.c
>>>> +++ b/drivers/usb/dwc3/host.c
>>>> @@ -13,6 +13,12 @@
>>>>  #include <linux/platform_device.h>
>>>>  
>>>>  #include "core.h"
>>>> +#include <linux/usb/xhci-plat.h>
>>>> +#include <linux/usb/xhci-quirks.h>
>>>> +
>>>> +static const struct xhci_plat_priv xhci_plat_dwc3_xhci = {
>>>> +	.quirks = XHCI_SKIP_PHY_INIT,
>>>> +};
>>>>  
>>>>  static void dwc3_host_fill_xhci_irq_res(struct dwc3 *dwc,
>>>>  					int irq, char *name)
>>>> @@ -122,6 +128,13 @@ int dwc3_host_init(struct dwc3 *dwc)
>>>>  		}
>>>>  	}
>>>>  
>>>> +	ret = platform_device_add_data(xhci, &xhci_plat_dwc3_xhci,
>>>> +			sizeof(xhci_plat_dwc3_xhci));
>>>> +	if (ret) {
>>>> +		dev_err(dwc->dev, "failed to add data to xHCI\n");
>>>> +		goto err;
>>>> +	}
>>>> +
>>>>  	ret = platform_device_add(xhci);
>>>>  	if (ret) {
>>>>  		dev_err(dwc->dev, "failed to register xHCI device\n");
>>>
>>> I think you should just use device property:
>>>
>>
>> This was suggested in an earlier series, but was rejected as it also added
>> the property as a device tree parameter.
>>
>> I think adding more device properties can be messy in the long run, especially if we
>> need to add them for many of the existing xhci quirks.
>> We also end up with a mix where some device properties are listed as device tree
>> parameters, and some not.
>>
>> Defining xhci quirks and platform data structure in headers shared with dwc3 and cdns3
>> allow those drivers to easily set any existing xhci quirk, or other possible optional
>> callbacks.
>>
>> cdns3 driver is already doing this, but it includes the full xhci.h header.
>> This series cleans up that a bit so cdns3 will only include xhci quirk bits and
>> platform data structure.
>>
>> On the downside we add a couple xhci related header files to include/linux/usb/
>> Let me know if you see any other issues I missed with this approach.
> 
> The problem here is that these drivers are now coupled together, and
> that should not be taken lightly. We have a dependency hell in our
> hands with a lot of drivers, and the culprit is always platform data.
> 
> Build-in device properties may be messy, but I would still say they
> are less messy than those quirk flags - you got to admit, they are a
> mess. The benefit from build-in properties is in any case the fact
> that they remove the need to couple these drivers together.

Agree, quirk bits are messy. Any suggestion that would work with
PCI xHCI devices, devicetree, and "pure" platform devices? 

> 
> You can also use something like naming convention if you are worried
> about confusion between devicetree properties and build-in only
> properties ("build-in:skip-phy-init" or whatever), and of course
> require that each of the build-in only property is documented clearly
> in drivers/usb/host/xhci-plat.c. But this in any case really can not
> be justification for a platform data blob just so you can avoid using
> the properties - honestly, it really should to be the other way
> around.
> 
> Platform data is in practice always problematic. On top of the driver
> coupling, it creates maintenance burden, code duplication, etc. Please
> don't just accept it lightly. I'm telling you, for hacks like this, the
> build-in device properties is a much much safer bet.
> 

Fair enough.

Any idea if there's a long term solution for platform devices?
Adding some type of "compatibility" id to platform devices in addition to name?

Also just noticed cdns3 driver passes a function pointer via platform_data to
xhci-plat. This should be cleared up as well.

Thanks
-Mathias

Re: [PATCH v3 3/3] usb: dwc: host: add xhci_plat_priv quirk XHCI_SKIP_PHY_INIT

[Heikki Krogerus]

On Fri, Mar 25, 2022 at 04:33:27PM +0200, Mathias Nyman wrote:
> On 25.3.2022 13.27, Heikki Krogerus wrote:
> > On Fri, Mar 25, 2022 at 12:36:22AM +0200, Mathias Nyman wrote:
> >> On 24.3.2022 14.27, Heikki Krogerus wrote:
> >>> On Thu, Mar 24, 2022 at 12:07:11PM +0530, Sandeep Maheswaram wrote:
> >>>> Currently the phy init is done from dwc3 and also xhci which makes the
> >>>> runtime_usage value 2 for the phy which causes issue during runtime
> >>>> suspend. When we run the below command the runtime_status still shows
> >>>> active.
> >>>> echo auto > /sys/bus/platform/devices/88e3000.phy/power/control
> >>>>
> >>>> dwc3 manages PHY by own DRD driver, so skip the management by
> >>>> HCD core by setting this quirk.
> >>>>
> >>>> Signed-off-by: Sandeep Maheswaram <quic_c_sanm@quicinc.com>
> >>>> ---
> >>>>  drivers/usb/dwc3/host.c | 13 +++++++++++++
> >>>>  1 file changed, 13 insertions(+)
> >>>>
> >>>> diff --git a/drivers/usb/dwc3/host.c b/drivers/usb/dwc3/host.c
> >>>> index eda8719..d4fcf06 100644
> >>>> --- a/drivers/usb/dwc3/host.c
> >>>> +++ b/drivers/usb/dwc3/host.c
> >>>> @@ -13,6 +13,12 @@
> >>>>  #include <linux/platform_device.h>
> >>>>  
> >>>>  #include "core.h"
> >>>> +#include <linux/usb/xhci-plat.h>
> >>>> +#include <linux/usb/xhci-quirks.h>
> >>>> +
> >>>> +static const struct xhci_plat_priv xhci_plat_dwc3_xhci = {
> >>>> +	.quirks = XHCI_SKIP_PHY_INIT,
> >>>> +};
> >>>>  
> >>>>  static void dwc3_host_fill_xhci_irq_res(struct dwc3 *dwc,
> >>>>  					int irq, char *name)
> >>>> @@ -122,6 +128,13 @@ int dwc3_host_init(struct dwc3 *dwc)
> >>>>  		}
> >>>>  	}
> >>>>  
> >>>> +	ret = platform_device_add_data(xhci, &xhci_plat_dwc3_xhci,
> >>>> +			sizeof(xhci_plat_dwc3_xhci));
> >>>> +	if (ret) {
> >>>> +		dev_err(dwc->dev, "failed to add data to xHCI\n");
> >>>> +		goto err;
> >>>> +	}
> >>>> +
> >>>>  	ret = platform_device_add(xhci);
> >>>>  	if (ret) {
> >>>>  		dev_err(dwc->dev, "failed to register xHCI device\n");
> >>>
> >>> I think you should just use device property:
> >>>
> >>
> >> This was suggested in an earlier series, but was rejected as it also added
> >> the property as a device tree parameter.
> >>
> >> I think adding more device properties can be messy in the long run, especially if we
> >> need to add them for many of the existing xhci quirks.
> >> We also end up with a mix where some device properties are listed as device tree
> >> parameters, and some not.
> >>
> >> Defining xhci quirks and platform data structure in headers shared with dwc3 and cdns3
> >> allow those drivers to easily set any existing xhci quirk, or other possible optional
> >> callbacks.
> >>
> >> cdns3 driver is already doing this, but it includes the full xhci.h header.
> >> This series cleans up that a bit so cdns3 will only include xhci quirk bits and
> >> platform data structure.
> >>
> >> On the downside we add a couple xhci related header files to include/linux/usb/
> >> Let me know if you see any other issues I missed with this approach.
> > 
> > The problem here is that these drivers are now coupled together, and
> > that should not be taken lightly. We have a dependency hell in our
> > hands with a lot of drivers, and the culprit is always platform data.
> > 
> > Build-in device properties may be messy, but I would still say they
> > are less messy than those quirk flags - you got to admit, they are a
> > mess. The benefit from build-in properties is in any case the fact
> > that they remove the need to couple these drivers together.
> 
> Agree, quirk bits are messy. Any suggestion that would work with
> PCI xHCI devices, devicetree, and "pure" platform devices? 

I think xHCI driver should always be able to rely on being able to
read this kind of information from the fwnode. If there is no actual
firmware node (DT or ACPI), or if it's missing some information, the
glue driver needs to populate software node for the xHCI.

Right now I just want to avoid having to pass the quirks using
platform data from drivers such as drivers/usb/cdns3/host.c and
drivers/usb/dwc3/host.c to xHCI.

One way we could do that is by defining compatibility ID for both of
them that we provide using a single device property (like I guess DT
does). Then based on that compatibility ID, xhci-plat.c can set the
actual "static" quirk flags. That we could already do easily. How
would that sound to you?

> > You can also use something like naming convention if you are worried
> > about confusion between devicetree properties and build-in only
> > properties ("build-in:skip-phy-init" or whatever), and of course
> > require that each of the build-in only property is documented clearly
> > in drivers/usb/host/xhci-plat.c. But this in any case really can not
> > be justification for a platform data blob just so you can avoid using
> > the properties - honestly, it really should to be the other way
> > around.
> > 
> > Platform data is in practice always problematic. On top of the driver
> > coupling, it creates maintenance burden, code duplication, etc. Please
> > don't just accept it lightly. I'm telling you, for hacks like this, the
> > build-in device properties is a much much safer bet.
> > 
> 
> Fair enough.
> 
> Any idea if there's a long term solution for platform devices?
> Adding some type of "compatibility" id to platform devices in addition to name?

We don't need to touch the platform devices if, and when, we have
always the fwnode. The "compatibility" id should always be possible to
pick from the fwnode.

> Also just noticed cdns3 driver passes a function pointer via platform_data to
> xhci-plat. This should be cleared up as well.

Looks like a PM quirk. For that I would propose this:
https://lore.kernel.org/linux-acpi/20201029105941.63410-2-heikki.krogerus@linux.intel.com/

So with that you can supply separate PM operations for your software
fwnode. When ever the device suspends, the suspend quirk is also
executed. xHCI core does not need to know about it.

Yeah, I guess I need to finish that series...

thanks,

-- 
heikki

Re: [PATCH v3 3/3] usb: dwc: host: add xhci_plat_priv quirk XHCI_SKIP_PHY_INIT

[Sandeep Maheswaram (Temp)]

Hi Mathias,Heikki

On 3/25/2022 9:08 PM, Heikki Krogerus wrote:
> On Fri, Mar 25, 2022 at 04:33:27PM +0200, Mathias Nyman wrote:
>> On 25.3.2022 13.27, Heikki Krogerus wrote:
>>> On Fri, Mar 25, 2022 at 12:36:22AM +0200, Mathias Nyman wrote:
>>>> On 24.3.2022 14.27, Heikki Krogerus wrote:
>>>>> On Thu, Mar 24, 2022 at 12:07:11PM +0530, Sandeep Maheswaram wrote:
>>>>>> Currently the phy init is done from dwc3 and also xhci which makes the
>>>>>> runtime_usage value 2 for the phy which causes issue during runtime
>>>>>> suspend. When we run the below command the runtime_status still shows
>>>>>> active.
>>>>>> echo auto > /sys/bus/platform/devices/88e3000.phy/power/control
>>>>>>
>>>>>> dwc3 manages PHY by own DRD driver, so skip the management by
>>>>>> HCD core by setting this quirk.
>>>>>>
>>>>>> Signed-off-by: Sandeep Maheswaram <quic_c_sanm@quicinc.com>
>>>>>> ---
>>>>>>   drivers/usb/dwc3/host.c | 13 +++++++++++++
>>>>>>   1 file changed, 13 insertions(+)
>>>>>>
>>>>>> diff --git a/drivers/usb/dwc3/host.c b/drivers/usb/dwc3/host.c
>>>>>> index eda8719..d4fcf06 100644
>>>>>> --- a/drivers/usb/dwc3/host.c
>>>>>> +++ b/drivers/usb/dwc3/host.c
>>>>>> @@ -13,6 +13,12 @@
>>>>>>   #include <linux/platform_device.h>
>>>>>>   
>>>>>>   #include "core.h"
>>>>>> +#include <linux/usb/xhci-plat.h>
>>>>>> +#include <linux/usb/xhci-quirks.h>
>>>>>> +
>>>>>> +static const struct xhci_plat_priv xhci_plat_dwc3_xhci = {
>>>>>> +	.quirks = XHCI_SKIP_PHY_INIT,
>>>>>> +};
>>>>>>   
>>>>>>   static void dwc3_host_fill_xhci_irq_res(struct dwc3 *dwc,
>>>>>>   					int irq, char *name)
>>>>>> @@ -122,6 +128,13 @@ int dwc3_host_init(struct dwc3 *dwc)
>>>>>>   		}
>>>>>>   	}
>>>>>>   
>>>>>> +	ret = platform_device_add_data(xhci, &xhci_plat_dwc3_xhci,
>>>>>> +			sizeof(xhci_plat_dwc3_xhci));
>>>>>> +	if (ret) {
>>>>>> +		dev_err(dwc->dev, "failed to add data to xHCI\n");
>>>>>> +		goto err;
>>>>>> +	}
>>>>>> +
>>>>>>   	ret = platform_device_add(xhci);
>>>>>>   	if (ret) {
>>>>>>   		dev_err(dwc->dev, "failed to register xHCI device\n");
>>>>> I think you should just use device property:
>>>>>
>>>> This was suggested in an earlier series, but was rejected as it also added
>>>> the property as a device tree parameter.
>>>>
>>>> I think adding more device properties can be messy in the long run, especially if we
>>>> need to add them for many of the existing xhci quirks.
>>>> We also end up with a mix where some device properties are listed as device tree
>>>> parameters, and some not.
>>>>
>>>> Defining xhci quirks and platform data structure in headers shared with dwc3 and cdns3
>>>> allow those drivers to easily set any existing xhci quirk, or other possible optional
>>>> callbacks.
>>>>
>>>> cdns3 driver is already doing this, but it includes the full xhci.h header.
>>>> This series cleans up that a bit so cdns3 will only include xhci quirk bits and
>>>> platform data structure.
>>>>
>>>> On the downside we add a couple xhci related header files to include/linux/usb/
>>>> Let me know if you see any other issues I missed with this approach.
>>> The problem here is that these drivers are now coupled together, and
>>> that should not be taken lightly. We have a dependency hell in our
>>> hands with a lot of drivers, and the culprit is always platform data.
>>>
>>> Build-in device properties may be messy, but I would still say they
>>> are less messy than those quirk flags - you got to admit, they are a
>>> mess. The benefit from build-in properties is in any case the fact
>>> that they remove the need to couple these drivers together.
>> Agree, quirk bits are messy. Any suggestion that would work with
>> PCI xHCI devices, devicetree, and "pure" platform devices?
> I think xHCI driver should always be able to rely on being able to
> read this kind of information from the fwnode. If there is no actual
> firmware node (DT or ACPI), or if it's missing some information, the
> glue driver needs to populate software node for the xHCI.
>
> Right now I just want to avoid having to pass the quirks using
> platform data from drivers such as drivers/usb/cdns3/host.c and
> drivers/usb/dwc3/host.c to xHCI.
>
> One way we could do that is by defining compatibility ID for both of
> them that we provide using a single device property (like I guess DT
> does). Then based on that compatibility ID, xhci-plat.c can set the
> actual "static" quirk flags. That we could already do easily. How
> would that sound to you?

This was my previous patch where I was using device tree property. 
Should we go ahead with this approach?

https://patchwork.kernel.org/project/linux-arm-msm/cover/1636353710-25582-1-git-send-email-quic_c_sanm@quicinc.com/

Any further changes to this ?

Regards

Sandeep

>
>>> You can also use something like naming convention if you are worried
>>> about confusion between devicetree properties and build-in only
>>> properties ("build-in:skip-phy-init" or whatever), and of course
>>> require that each of the build-in only property is documented clearly
>>> in drivers/usb/host/xhci-plat.c. But this in any case really can not
>>> be justification for a platform data blob just so you can avoid using
>>> the properties - honestly, it really should to be the other way
>>> around.
>>>
>>> Platform data is in practice always problematic. On top of the driver
>>> coupling, it creates maintenance burden, code duplication, etc. Please
>>> don't just accept it lightly. I'm telling you, for hacks like this, the
>>> build-in device properties is a much much safer bet.
>>>
>> Fair enough.
>>
>> Any idea if there's a long term solution for platform devices?
>> Adding some type of "compatibility" id to platform devices in addition to name?
> We don't need to touch the platform devices if, and when, we have
> always the fwnode. The "compatibility" id should always be possible to
> pick from the fwnode.
>
>> Also just noticed cdns3 driver passes a function pointer via platform_data to
>> xhci-plat. This should be cleared up as well.
> Looks like a PM quirk. For that I would propose this:
> https://lore.kernel.org/linux-acpi/20201029105941.63410-2-heikki.krogerus@linux.intel.com/
>
> So with that you can supply separate PM operations for your software
> fwnode. When ever the device suspends, the suspend quirk is also
> executed. xHCI core does not need to know about it.
>
> Yeah, I guess I need to finish that series...
>
> thanks,
>

Re: [PATCH v3 3/3] usb: dwc: host: add xhci_plat_priv quirk XHCI_SKIP_PHY_INIT

[Pavan Kondeti]

On Tue, Mar 29, 2022 at 02:48:05PM +0530, Sandeep Maheswaram (Temp) wrote:
> Hi Mathias,Heikki
> 
> On 3/25/2022 9:08 PM, Heikki Krogerus wrote:
> >On Fri, Mar 25, 2022 at 04:33:27PM +0200, Mathias Nyman wrote:
> >>On 25.3.2022 13.27, Heikki Krogerus wrote:
> >>>On Fri, Mar 25, 2022 at 12:36:22AM +0200, Mathias Nyman wrote:
> >>>>On 24.3.2022 14.27, Heikki Krogerus wrote:
> >>>>>On Thu, Mar 24, 2022 at 12:07:11PM +0530, Sandeep Maheswaram wrote:
> >>>>>>Currently the phy init is done from dwc3 and also xhci which makes the
> >>>>>>runtime_usage value 2 for the phy which causes issue during runtime
> >>>>>>suspend. When we run the below command the runtime_status still shows
> >>>>>>active.
> >>>>>>echo auto > /sys/bus/platform/devices/88e3000.phy/power/control
> >>>>>>
> >>>>>>dwc3 manages PHY by own DRD driver, so skip the management by
> >>>>>>HCD core by setting this quirk.
> >>>>>>
> >>>>>>Signed-off-by: Sandeep Maheswaram <quic_c_sanm@quicinc.com>
> >>>>>>---
> >>>>>>  drivers/usb/dwc3/host.c | 13 +++++++++++++
> >>>>>>  1 file changed, 13 insertions(+)
> >>>>>>
> >>>>>>diff --git a/drivers/usb/dwc3/host.c b/drivers/usb/dwc3/host.c
> >>>>>>index eda8719..d4fcf06 100644
> >>>>>>--- a/drivers/usb/dwc3/host.c
> >>>>>>+++ b/drivers/usb/dwc3/host.c
> >>>>>>@@ -13,6 +13,12 @@
> >>>>>>  #include <linux/platform_device.h>
> >>>>>>  #include "core.h"
> >>>>>>+#include <linux/usb/xhci-plat.h>
> >>>>>>+#include <linux/usb/xhci-quirks.h>
> >>>>>>+
> >>>>>>+static const struct xhci_plat_priv xhci_plat_dwc3_xhci = {
> >>>>>>+	.quirks = XHCI_SKIP_PHY_INIT,
> >>>>>>+};
> >>>>>>  static void dwc3_host_fill_xhci_irq_res(struct dwc3 *dwc,
> >>>>>>  					int irq, char *name)
> >>>>>>@@ -122,6 +128,13 @@ int dwc3_host_init(struct dwc3 *dwc)
> >>>>>>  		}
> >>>>>>  	}
> >>>>>>+	ret = platform_device_add_data(xhci, &xhci_plat_dwc3_xhci,
> >>>>>>+			sizeof(xhci_plat_dwc3_xhci));
> >>>>>>+	if (ret) {
> >>>>>>+		dev_err(dwc->dev, "failed to add data to xHCI\n");
> >>>>>>+		goto err;
> >>>>>>+	}
> >>>>>>+
> >>>>>>  	ret = platform_device_add(xhci);
> >>>>>>  	if (ret) {
> >>>>>>  		dev_err(dwc->dev, "failed to register xHCI device\n");
> >>>>>I think you should just use device property:
> >>>>>
> >>>>This was suggested in an earlier series, but was rejected as it also added
> >>>>the property as a device tree parameter.
> >>>>
> >>>>I think adding more device properties can be messy in the long run, especially if we
> >>>>need to add them for many of the existing xhci quirks.
> >>>>We also end up with a mix where some device properties are listed as device tree
> >>>>parameters, and some not.
> >>>>
> >>>>Defining xhci quirks and platform data structure in headers shared with dwc3 and cdns3
> >>>>allow those drivers to easily set any existing xhci quirk, or other possible optional
> >>>>callbacks.
> >>>>
> >>>>cdns3 driver is already doing this, but it includes the full xhci.h header.
> >>>>This series cleans up that a bit so cdns3 will only include xhci quirk bits and
> >>>>platform data structure.
> >>>>
> >>>>On the downside we add a couple xhci related header files to include/linux/usb/
> >>>>Let me know if you see any other issues I missed with this approach.
> >>>The problem here is that these drivers are now coupled together, and
> >>>that should not be taken lightly. We have a dependency hell in our
> >>>hands with a lot of drivers, and the culprit is always platform data.
> >>>
> >>>Build-in device properties may be messy, but I would still say they
> >>>are less messy than those quirk flags - you got to admit, they are a
> >>>mess. The benefit from build-in properties is in any case the fact
> >>>that they remove the need to couple these drivers together.
> >>Agree, quirk bits are messy. Any suggestion that would work with
> >>PCI xHCI devices, devicetree, and "pure" platform devices?
> >I think xHCI driver should always be able to rely on being able to
> >read this kind of information from the fwnode. If there is no actual
> >firmware node (DT or ACPI), or if it's missing some information, the
> >glue driver needs to populate software node for the xHCI.
> >
> >Right now I just want to avoid having to pass the quirks using
> >platform data from drivers such as drivers/usb/cdns3/host.c and
> >drivers/usb/dwc3/host.c to xHCI.
> >
> >One way we could do that is by defining compatibility ID for both of
> >them that we provide using a single device property (like I guess DT
> >does). Then based on that compatibility ID, xhci-plat.c can set the
> >actual "static" quirk flags. That we could already do easily. How
> >would that sound to you?
> 
> This was my previous patch where I was using device tree property. Should we
> go ahead with this approach?
> 
> https://patchwork.kernel.org/project/linux-arm-msm/cover/1636353710-25582-1-git-send-email-quic_c_sanm@quicinc.com/
> 
> Any further changes to this ?
> 

Actually the dT idea looks better than the platform data. Earlier, we decided
to use if (of_device_is_compatible(dev->parent->of_node, "snps,dwc3")) check
but I feel that we should just introduce a device tree param that specify
this functionality (skipping phy init). we don't want xhci-plat to know that
this is dwc3/xyz device. we expect it to be abstracted.

Thanks,
Pavan

Re: [PATCH v3 3/3] usb: dwc: host: add xhci_plat_priv quirk XHCI_SKIP_PHY_INIT

[Mathias Nyman]

On 29.3.2022 12.18, Sandeep Maheswaram (Temp) wrote:
> Hi Mathias,Heikki
> 
> On 3/25/2022 9:08 PM, Heikki Krogerus wrote:
>> On Fri, Mar 25, 2022 at 04:33:27PM +0200, Mathias Nyman wrote:
>>> On 25.3.2022 13.27, Heikki Krogerus wrote:
>>>> On Fri, Mar 25, 2022 at 12:36:22AM +0200, Mathias Nyman wrote:
>>>>> On 24.3.2022 14.27, Heikki Krogerus wrote:
>>>>>> On Thu, Mar 24, 2022 at 12:07:11PM +0530, Sandeep Maheswaram wrote:
>>>>>>> Currently the phy init is done from dwc3 and also xhci which makes the
>>>>>>> runtime_usage value 2 for the phy which causes issue during runtime
>>>>>>> suspend. When we run the below command the runtime_status still shows
>>>>>>> active.
>>>>>>> echo auto > /sys/bus/platform/devices/88e3000.phy/power/control
>>>>>>>
>>>>>>> dwc3 manages PHY by own DRD driver, so skip the management by
>>>>>>> HCD core by setting this quirk.
>>>>>>>
>>>>>>> Signed-off-by: Sandeep Maheswaram <quic_c_sanm@quicinc.com>
>>>>>>> ---
>>>>>>>   drivers/usb/dwc3/host.c | 13 +++++++++++++
>>>>>>>   1 file changed, 13 insertions(+)
>>>>>>>
>>>>>>> diff --git a/drivers/usb/dwc3/host.c b/drivers/usb/dwc3/host.c
>>>>>>> index eda8719..d4fcf06 100644
>>>>>>> --- a/drivers/usb/dwc3/host.c
>>>>>>> +++ b/drivers/usb/dwc3/host.c
>>>>>>> @@ -13,6 +13,12 @@
>>>>>>>   #include <linux/platform_device.h>
>>>>>>>     #include "core.h"
>>>>>>> +#include <linux/usb/xhci-plat.h>
>>>>>>> +#include <linux/usb/xhci-quirks.h>
>>>>>>> +
>>>>>>> +static const struct xhci_plat_priv xhci_plat_dwc3_xhci = {
>>>>>>> +    .quirks = XHCI_SKIP_PHY_INIT,
>>>>>>> +};
>>>>>>>     static void dwc3_host_fill_xhci_irq_res(struct dwc3 *dwc,
>>>>>>>                       int irq, char *name)
>>>>>>> @@ -122,6 +128,13 @@ int dwc3_host_init(struct dwc3 *dwc)
>>>>>>>           }
>>>>>>>       }
>>>>>>>   +    ret = platform_device_add_data(xhci, &xhci_plat_dwc3_xhci,
>>>>>>> +            sizeof(xhci_plat_dwc3_xhci));
>>>>>>> +    if (ret) {
>>>>>>> +        dev_err(dwc->dev, "failed to add data to xHCI\n");
>>>>>>> +        goto err;
>>>>>>> +    }
>>>>>>> +
>>>>>>>       ret = platform_device_add(xhci);
>>>>>>>       if (ret) {
>>>>>>>           dev_err(dwc->dev, "failed to register xHCI device\n");
>>>>>> I think you should just use device property:
>>>>>>
>>>>> This was suggested in an earlier series, but was rejected as it also added
>>>>> the property as a device tree parameter.
>>>>>
>>>>> I think adding more device properties can be messy in the long run, especially if we
>>>>> need to add them for many of the existing xhci quirks.
>>>>> We also end up with a mix where some device properties are listed as device tree
>>>>> parameters, and some not.
>>>>>
>>>>> Defining xhci quirks and platform data structure in headers shared with dwc3 and cdns3
>>>>> allow those drivers to easily set any existing xhci quirk, or other possible optional
>>>>> callbacks.
>>>>>
>>>>> cdns3 driver is already doing this, but it includes the full xhci.h header.
>>>>> This series cleans up that a bit so cdns3 will only include xhci quirk bits and
>>>>> platform data structure.
>>>>>
>>>>> On the downside we add a couple xhci related header files to include/linux/usb/
>>>>> Let me know if you see any other issues I missed with this approach.
>>>> The problem here is that these drivers are now coupled together, and
>>>> that should not be taken lightly. We have a dependency hell in our
>>>> hands with a lot of drivers, and the culprit is always platform data.
>>>>
>>>> Build-in device properties may be messy, but I would still say they
>>>> are less messy than those quirk flags - you got to admit, they are a
>>>> mess. The benefit from build-in properties is in any case the fact
>>>> that they remove the need to couple these drivers together.
>>> Agree, quirk bits are messy. Any suggestion that would work with
>>> PCI xHCI devices, devicetree, and "pure" platform devices?
>> I think xHCI driver should always be able to rely on being able to
>> read this kind of information from the fwnode. If there is no actual
>> firmware node (DT or ACPI), or if it's missing some information, the
>> glue driver needs to populate software node for the xHCI.
>>
>> Right now I just want to avoid having to pass the quirks using
>> platform data from drivers such as drivers/usb/cdns3/host.c and
>> drivers/usb/dwc3/host.c to xHCI.
>>
>> One way we could do that is by defining compatibility ID for both of
>> them that we provide using a single device property (like I guess DT
>> does). Then based on that compatibility ID, xhci-plat.c can set the
>> actual "static" quirk flags. That we could already do easily. How
>> would that sound to you?

Sounds good. 

> 
> This was my previous patch where I was using device tree property. Should we go ahead with this approach?
> 
> https://patchwork.kernel.org/project/linux-arm-msm/cover/1636353710-25582-1-git-send-email-quic_c_sanm@quicinc.com/
> 
> Any further changes to this ?

By dropping the DT part of that series we get a similar built-in device property
solution as Heikki initially suggested.

How about adding the compatibility ID device property that was just suggested?
Then matching the Id in xhci-plat.c against a static table containing Ids and
xhci_plat_priv structures, with the needed quirks for dwc3.

Thanks
-Mathias

Re: [PATCH v3 3/3] usb: dwc: host: add xhci_plat_priv quirk XHCI_SKIP_PHY_INIT

[Heikki Krogerus]

On Wed, Mar 30, 2022 at 08:47:34PM +0300, Mathias Nyman wrote:
> On 29.3.2022 12.18, Sandeep Maheswaram (Temp) wrote:
> > Hi Mathias,Heikki
> > 
> > On 3/25/2022 9:08 PM, Heikki Krogerus wrote:
> >> On Fri, Mar 25, 2022 at 04:33:27PM +0200, Mathias Nyman wrote:
> >>> On 25.3.2022 13.27, Heikki Krogerus wrote:
> >>>> On Fri, Mar 25, 2022 at 12:36:22AM +0200, Mathias Nyman wrote:
> >>>>> On 24.3.2022 14.27, Heikki Krogerus wrote:
> >>>>>> On Thu, Mar 24, 2022 at 12:07:11PM +0530, Sandeep Maheswaram wrote:
> >>>>>>> Currently the phy init is done from dwc3 and also xhci which makes the
> >>>>>>> runtime_usage value 2 for the phy which causes issue during runtime
> >>>>>>> suspend. When we run the below command the runtime_status still shows
> >>>>>>> active.
> >>>>>>> echo auto > /sys/bus/platform/devices/88e3000.phy/power/control
> >>>>>>>
> >>>>>>> dwc3 manages PHY by own DRD driver, so skip the management by
> >>>>>>> HCD core by setting this quirk.
> >>>>>>>
> >>>>>>> Signed-off-by: Sandeep Maheswaram <quic_c_sanm@quicinc.com>
> >>>>>>> ---
> >>>>>>>   drivers/usb/dwc3/host.c | 13 +++++++++++++
> >>>>>>>   1 file changed, 13 insertions(+)
> >>>>>>>
> >>>>>>> diff --git a/drivers/usb/dwc3/host.c b/drivers/usb/dwc3/host.c
> >>>>>>> index eda8719..d4fcf06 100644
> >>>>>>> --- a/drivers/usb/dwc3/host.c
> >>>>>>> +++ b/drivers/usb/dwc3/host.c
> >>>>>>> @@ -13,6 +13,12 @@
> >>>>>>>   #include <linux/platform_device.h>
> >>>>>>>     #include "core.h"
> >>>>>>> +#include <linux/usb/xhci-plat.h>
> >>>>>>> +#include <linux/usb/xhci-quirks.h>
> >>>>>>> +
> >>>>>>> +static const struct xhci_plat_priv xhci_plat_dwc3_xhci = {
> >>>>>>> +    .quirks = XHCI_SKIP_PHY_INIT,
> >>>>>>> +};
> >>>>>>>     static void dwc3_host_fill_xhci_irq_res(struct dwc3 *dwc,
> >>>>>>>                       int irq, char *name)
> >>>>>>> @@ -122,6 +128,13 @@ int dwc3_host_init(struct dwc3 *dwc)
> >>>>>>>           }
> >>>>>>>       }
> >>>>>>>   +    ret = platform_device_add_data(xhci, &xhci_plat_dwc3_xhci,
> >>>>>>> +            sizeof(xhci_plat_dwc3_xhci));
> >>>>>>> +    if (ret) {
> >>>>>>> +        dev_err(dwc->dev, "failed to add data to xHCI\n");
> >>>>>>> +        goto err;
> >>>>>>> +    }
> >>>>>>> +
> >>>>>>>       ret = platform_device_add(xhci);
> >>>>>>>       if (ret) {
> >>>>>>>           dev_err(dwc->dev, "failed to register xHCI device\n");
> >>>>>> I think you should just use device property:
> >>>>>>
> >>>>> This was suggested in an earlier series, but was rejected as it also added
> >>>>> the property as a device tree parameter.
> >>>>>
> >>>>> I think adding more device properties can be messy in the long run, especially if we
> >>>>> need to add them for many of the existing xhci quirks.
> >>>>> We also end up with a mix where some device properties are listed as device tree
> >>>>> parameters, and some not.
> >>>>>
> >>>>> Defining xhci quirks and platform data structure in headers shared with dwc3 and cdns3
> >>>>> allow those drivers to easily set any existing xhci quirk, or other possible optional
> >>>>> callbacks.
> >>>>>
> >>>>> cdns3 driver is already doing this, but it includes the full xhci.h header.
> >>>>> This series cleans up that a bit so cdns3 will only include xhci quirk bits and
> >>>>> platform data structure.
> >>>>>
> >>>>> On the downside we add a couple xhci related header files to include/linux/usb/
> >>>>> Let me know if you see any other issues I missed with this approach.
> >>>> The problem here is that these drivers are now coupled together, and
> >>>> that should not be taken lightly. We have a dependency hell in our
> >>>> hands with a lot of drivers, and the culprit is always platform data.
> >>>>
> >>>> Build-in device properties may be messy, but I would still say they
> >>>> are less messy than those quirk flags - you got to admit, they are a
> >>>> mess. The benefit from build-in properties is in any case the fact
> >>>> that they remove the need to couple these drivers together.
> >>> Agree, quirk bits are messy. Any suggestion that would work with
> >>> PCI xHCI devices, devicetree, and "pure" platform devices?
> >> I think xHCI driver should always be able to rely on being able to
> >> read this kind of information from the fwnode. If there is no actual
> >> firmware node (DT or ACPI), or if it's missing some information, the
> >> glue driver needs to populate software node for the xHCI.
> >>
> >> Right now I just want to avoid having to pass the quirks using
> >> platform data from drivers such as drivers/usb/cdns3/host.c and
> >> drivers/usb/dwc3/host.c to xHCI.
> >>
> >> One way we could do that is by defining compatibility ID for both of
> >> them that we provide using a single device property (like I guess DT
> >> does). Then based on that compatibility ID, xhci-plat.c can set the
> >> actual "static" quirk flags. That we could already do easily. How
> >> would that sound to you?
> 
> Sounds good. 
> 
> > 
> > This was my previous patch where I was using device tree property. Should we go ahead with this approach?
> > 
> > https://patchwork.kernel.org/project/linux-arm-msm/cover/1636353710-25582-1-git-send-email-quic_c_sanm@quicinc.com/
> > 
> > Any further changes to this ?
> 
> By dropping the DT part of that series we get a similar built-in device property
> solution as Heikki initially suggested.
> 
> How about adding the compatibility ID device property that was just suggested?
> Then matching the Id in xhci-plat.c against a static table containing Ids and
> xhci_plat_priv structures, with the needed quirks for dwc3.

There was a comment from Pavan. Is it still possible to get this
detail from DT?
I guess that would still be ideal, right?

I have another question. Can't we now just assume that if the sysdev
is the parent (or grandparent), then the phy initialization should
always be skipped? In that case we could just do something like this:

diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
index 649ffd861b44e..1018b33488046 100644
--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -212,8 +212,12 @@ static int xhci_plat_probe(struct platform_device *pdev)
 #endif
        }
 
-       if (!sysdev)
+       if (sysdev) {
+               if (sysdev != &pdev->dev)
+                       hcd->skip_phy_initialization = 1;
+       } else {
                sysdev = &pdev->dev;
+       }
 
        if (WARN_ON(!sysdev->dma_mask))
                /* Platform did not initialize dma_mask */


I did not go through all the drivers that carefully, so I may have
missed something, but it looks like the only drivers that can have the
sysdev as the parent or grandparent are cdns3 and dwc3.

thanks,

-- 
heikki

Re: [PATCH v3 3/3] usb: dwc: host: add xhci_plat_priv quirk XHCI_SKIP_PHY_INIT

[Pavan Kondeti]

Hi Heikki,

On Thu, Mar 31, 2022 at 02:16:53PM +0300, Heikki Krogerus wrote:
> On Wed, Mar 30, 2022 at 08:47:34PM +0300, Mathias Nyman wrote:
> > On 29.3.2022 12.18, Sandeep Maheswaram (Temp) wrote:
> > > Hi Mathias,Heikki
> > > 
> > > On 3/25/2022 9:08 PM, Heikki Krogerus wrote:
> > >> On Fri, Mar 25, 2022 at 04:33:27PM +0200, Mathias Nyman wrote:
> > >>> On 25.3.2022 13.27, Heikki Krogerus wrote:
> > >>>> On Fri, Mar 25, 2022 at 12:36:22AM +0200, Mathias Nyman wrote:
> > >>>>> On 24.3.2022 14.27, Heikki Krogerus wrote:
> > >>>>>> On Thu, Mar 24, 2022 at 12:07:11PM +0530, Sandeep Maheswaram wrote:
> > >>>>>>> Currently the phy init is done from dwc3 and also xhci which makes the
> > >>>>>>> runtime_usage value 2 for the phy which causes issue during runtime
> > >>>>>>> suspend. When we run the below command the runtime_status still shows
> > >>>>>>> active.
> > >>>>>>> echo auto > /sys/bus/platform/devices/88e3000.phy/power/control
> > >>>>>>>
> > >>>>>>> dwc3 manages PHY by own DRD driver, so skip the management by
> > >>>>>>> HCD core by setting this quirk.
> > >>>>>>>
> > >>>>>>> Signed-off-by: Sandeep Maheswaram <quic_c_sanm@quicinc.com>
> > >>>>>>> ---
> > >>>>>>>   drivers/usb/dwc3/host.c | 13 +++++++++++++
> > >>>>>>>   1 file changed, 13 insertions(+)
> > >>>>>>>
> > >>>>>>> diff --git a/drivers/usb/dwc3/host.c b/drivers/usb/dwc3/host.c
> > >>>>>>> index eda8719..d4fcf06 100644
> > >>>>>>> --- a/drivers/usb/dwc3/host.c
> > >>>>>>> +++ b/drivers/usb/dwc3/host.c
> > >>>>>>> @@ -13,6 +13,12 @@
> > >>>>>>>   #include <linux/platform_device.h>
> > >>>>>>>     #include "core.h"
> > >>>>>>> +#include <linux/usb/xhci-plat.h>
> > >>>>>>> +#include <linux/usb/xhci-quirks.h>
> > >>>>>>> +
> > >>>>>>> +static const struct xhci_plat_priv xhci_plat_dwc3_xhci = {
> > >>>>>>> +    .quirks = XHCI_SKIP_PHY_INIT,
> > >>>>>>> +};
> > >>>>>>>     static void dwc3_host_fill_xhci_irq_res(struct dwc3 *dwc,
> > >>>>>>>                       int irq, char *name)
> > >>>>>>> @@ -122,6 +128,13 @@ int dwc3_host_init(struct dwc3 *dwc)
> > >>>>>>>           }
> > >>>>>>>       }
> > >>>>>>>   +    ret = platform_device_add_data(xhci, &xhci_plat_dwc3_xhci,
> > >>>>>>> +            sizeof(xhci_plat_dwc3_xhci));
> > >>>>>>> +    if (ret) {
> > >>>>>>> +        dev_err(dwc->dev, "failed to add data to xHCI\n");
> > >>>>>>> +        goto err;
> > >>>>>>> +    }
> > >>>>>>> +
> > >>>>>>>       ret = platform_device_add(xhci);
> > >>>>>>>       if (ret) {
> > >>>>>>>           dev_err(dwc->dev, "failed to register xHCI device\n");
> > >>>>>> I think you should just use device property:
> > >>>>>>
> > >>>>> This was suggested in an earlier series, but was rejected as it also added
> > >>>>> the property as a device tree parameter.
> > >>>>>
> > >>>>> I think adding more device properties can be messy in the long run, especially if we
> > >>>>> need to add them for many of the existing xhci quirks.
> > >>>>> We also end up with a mix where some device properties are listed as device tree
> > >>>>> parameters, and some not.
> > >>>>>
> > >>>>> Defining xhci quirks and platform data structure in headers shared with dwc3 and cdns3
> > >>>>> allow those drivers to easily set any existing xhci quirk, or other possible optional
> > >>>>> callbacks.
> > >>>>>
> > >>>>> cdns3 driver is already doing this, but it includes the full xhci.h header.
> > >>>>> This series cleans up that a bit so cdns3 will only include xhci quirk bits and
> > >>>>> platform data structure.
> > >>>>>
> > >>>>> On the downside we add a couple xhci related header files to include/linux/usb/
> > >>>>> Let me know if you see any other issues I missed with this approach.
> > >>>> The problem here is that these drivers are now coupled together, and
> > >>>> that should not be taken lightly. We have a dependency hell in our
> > >>>> hands with a lot of drivers, and the culprit is always platform data.
> > >>>>
> > >>>> Build-in device properties may be messy, but I would still say they
> > >>>> are less messy than those quirk flags - you got to admit, they are a
> > >>>> mess. The benefit from build-in properties is in any case the fact
> > >>>> that they remove the need to couple these drivers together.
> > >>> Agree, quirk bits are messy. Any suggestion that would work with
> > >>> PCI xHCI devices, devicetree, and "pure" platform devices?
> > >> I think xHCI driver should always be able to rely on being able to
> > >> read this kind of information from the fwnode. If there is no actual
> > >> firmware node (DT or ACPI), or if it's missing some information, the
> > >> glue driver needs to populate software node for the xHCI.
> > >>
> > >> Right now I just want to avoid having to pass the quirks using
> > >> platform data from drivers such as drivers/usb/cdns3/host.c and
> > >> drivers/usb/dwc3/host.c to xHCI.
> > >>
> > >> One way we could do that is by defining compatibility ID for both of
> > >> them that we provide using a single device property (like I guess DT
> > >> does). Then based on that compatibility ID, xhci-plat.c can set the
> > >> actual "static" quirk flags. That we could already do easily. How
> > >> would that sound to you?
> > 
> > Sounds good. 
> > 
> > > 
> > > This was my previous patch where I was using device tree property. Should we go ahead with this approach?
> > > 
> > > https://patchwork.kernel.org/project/linux-arm-msm/cover/1636353710-25582-1-git-send-email-quic_c_sanm@quicinc.com/
> > > 
> > > Any further changes to this ?
> > 
> > By dropping the DT part of that series we get a similar built-in device property
> > solution as Heikki initially suggested.
> > 
> > How about adding the compatibility ID device property that was just suggested?
> > Then matching the Id in xhci-plat.c against a static table containing Ids and
> > xhci_plat_priv structures, with the needed quirks for dwc3.
> 
> There was a comment from Pavan. Is it still possible to get this
> detail from DT?
> I guess that would still be ideal, right?
> 
I was suggesting if we can have device tree param like the patch sandeep
pointed out.

How would adding a compatible index to usb_xhci_of_match[] would work
actually? I ask this because, dwc3/host.c creates platform device and
it is not associated with any of_node, so of_driver_match_device() called
from platform bus match method does not work. one way to achieve this would
be by matching against sysdev. Something like below. Is it acceptible?

diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
index 649ffd8..bd5d055 100644
--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -126,6 +126,10 @@ static const struct xhci_plat_priv xhci_plat_brcm = {
 	.quirks = XHCI_RESET_ON_RESUME,
 };
 
+static const struct xhci_plat_priv xhci_plat_dwc3 = {
+	.quirks = XHCI_SKIP_PHY_INIT,
+};
+
 static const struct of_device_id usb_xhci_of_match[] = {
 	{
 		.compatible = "generic-xhci",
@@ -167,6 +171,9 @@ static const struct of_device_id usb_xhci_of_match[] = {
 	}, {
 		.compatible = "brcm,bcm7445-xhci",
 		.data = &xhci_plat_brcm,
+	}, {
+		.compatible = "snps,dwc3",
+		.data = &xhci_plat_dwc3,
 	},
 	{},
 };
@@ -274,6 +281,15 @@ static int xhci_plat_probe(struct platform_device *pdev)
 	else
 		priv_match = dev_get_platdata(&pdev->dev);
 
+	/* allow private data mapping with the sysdev compatible */
+	if (!priv_match) {
+		struct of_device_id *match;
+
+		match = of_match_device(usb_xhci_of_match, sysdev);
+		if (match)
+			priv_match = match->data;
+	}
+
 	if (priv_match) {
 		priv = hcd_to_xhci_priv(hcd);
 		/* Just copy data for now */

> I have another question. Can't we now just assume that if the sysdev
> is the parent (or grandparent), then the phy initialization should
> always be skipped? In that case we could just do something like this:
> 
> diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
> index 649ffd861b44e..1018b33488046 100644
> --- a/drivers/usb/host/xhci-plat.c
> +++ b/drivers/usb/host/xhci-plat.c
> @@ -212,8 +212,12 @@ static int xhci_plat_probe(struct platform_device *pdev)
>  #endif
>         }
>  
> -       if (!sysdev)
> +       if (sysdev) {
> +               if (sysdev != &pdev->dev)
> +                       hcd->skip_phy_initialization = 1;
> +       } else {
>                 sysdev = &pdev->dev;
> +       }
>  
>         if (WARN_ON(!sysdev->dma_mask))
>                 /* Platform did not initialize dma_mask */
> 
> 
> I did not go through all the drivers that carefully, so I may have
> missed something, but it looks like the only drivers that can have the
> sysdev as the parent or grandparent are cdns3 and dwc3.
> 
I cross checked and these are two drivers that are creating xhci-plat device.
So this patch would definitely work. However I am not sure in future if any
device created via device tree would want to use this feature. For now,
it looks good. It Mathias, Do you see any problem with this approach?

Thanks,
Pavan

Re: [PATCH v3 3/3] usb: dwc: host: add xhci_plat_priv quirk XHCI_SKIP_PHY_INIT

[Pavan Kondeti]

Hi Heikki/Mathias,

On Mon, Apr 04, 2022 at 01:55:16PM +0530, Pavan Kondeti wrote:
> Hi Heikki,
> 
> On Thu, Mar 31, 2022 at 02:16:53PM +0300, Heikki Krogerus wrote:
> > On Wed, Mar 30, 2022 at 08:47:34PM +0300, Mathias Nyman wrote:
> > > On 29.3.2022 12.18, Sandeep Maheswaram (Temp) wrote:
> > > > Hi Mathias,Heikki
> > > > 
> > > > On 3/25/2022 9:08 PM, Heikki Krogerus wrote:
> > > >> On Fri, Mar 25, 2022 at 04:33:27PM +0200, Mathias Nyman wrote:
> > > >>> On 25.3.2022 13.27, Heikki Krogerus wrote:
> > > >>>> On Fri, Mar 25, 2022 at 12:36:22AM +0200, Mathias Nyman wrote:
> > > >>>>> On 24.3.2022 14.27, Heikki Krogerus wrote:
> > > >>>>>> On Thu, Mar 24, 2022 at 12:07:11PM +0530, Sandeep Maheswaram wrote:
> > > >>>>>>> Currently the phy init is done from dwc3 and also xhci which makes the
> > > >>>>>>> runtime_usage value 2 for the phy which causes issue during runtime
> > > >>>>>>> suspend. When we run the below command the runtime_status still shows
> > > >>>>>>> active.
> > > >>>>>>> echo auto > /sys/bus/platform/devices/88e3000.phy/power/control
> > > >>>>>>>
> > > >>>>>>> dwc3 manages PHY by own DRD driver, so skip the management by
> > > >>>>>>> HCD core by setting this quirk.
> > > >>>>>>>
> > > >>>>>>> Signed-off-by: Sandeep Maheswaram <quic_c_sanm@quicinc.com>
> > > >>>>>>> ---
> > > >>>>>>>   drivers/usb/dwc3/host.c | 13 +++++++++++++
> > > >>>>>>>   1 file changed, 13 insertions(+)
> > > >>>>>>>
> > > >>>>>>> diff --git a/drivers/usb/dwc3/host.c b/drivers/usb/dwc3/host.c
> > > >>>>>>> index eda8719..d4fcf06 100644
> > > >>>>>>> --- a/drivers/usb/dwc3/host.c
> > > >>>>>>> +++ b/drivers/usb/dwc3/host.c
> > > >>>>>>> @@ -13,6 +13,12 @@
> > > >>>>>>>   #include <linux/platform_device.h>
> > > >>>>>>>     #include "core.h"
> > > >>>>>>> +#include <linux/usb/xhci-plat.h>
> > > >>>>>>> +#include <linux/usb/xhci-quirks.h>
> > > >>>>>>> +
> > > >>>>>>> +static const struct xhci_plat_priv xhci_plat_dwc3_xhci = {
> > > >>>>>>> +    .quirks = XHCI_SKIP_PHY_INIT,
> > > >>>>>>> +};
> > > >>>>>>>     static void dwc3_host_fill_xhci_irq_res(struct dwc3 *dwc,
> > > >>>>>>>                       int irq, char *name)
> > > >>>>>>> @@ -122,6 +128,13 @@ int dwc3_host_init(struct dwc3 *dwc)
> > > >>>>>>>           }
> > > >>>>>>>       }
> > > >>>>>>>   +    ret = platform_device_add_data(xhci, &xhci_plat_dwc3_xhci,
> > > >>>>>>> +            sizeof(xhci_plat_dwc3_xhci));
> > > >>>>>>> +    if (ret) {
> > > >>>>>>> +        dev_err(dwc->dev, "failed to add data to xHCI\n");
> > > >>>>>>> +        goto err;
> > > >>>>>>> +    }
> > > >>>>>>> +
> > > >>>>>>>       ret = platform_device_add(xhci);
> > > >>>>>>>       if (ret) {
> > > >>>>>>>           dev_err(dwc->dev, "failed to register xHCI device\n");
> > > >>>>>> I think you should just use device property:
> > > >>>>>>
> > > >>>>> This was suggested in an earlier series, but was rejected as it also added
> > > >>>>> the property as a device tree parameter.
> > > >>>>>
> > > >>>>> I think adding more device properties can be messy in the long run, especially if we
> > > >>>>> need to add them for many of the existing xhci quirks.
> > > >>>>> We also end up with a mix where some device properties are listed as device tree
> > > >>>>> parameters, and some not.
> > > >>>>>
> > > >>>>> Defining xhci quirks and platform data structure in headers shared with dwc3 and cdns3
> > > >>>>> allow those drivers to easily set any existing xhci quirk, or other possible optional
> > > >>>>> callbacks.
> > > >>>>>
> > > >>>>> cdns3 driver is already doing this, but it includes the full xhci.h header.
> > > >>>>> This series cleans up that a bit so cdns3 will only include xhci quirk bits and
> > > >>>>> platform data structure.
> > > >>>>>
> > > >>>>> On the downside we add a couple xhci related header files to include/linux/usb/
> > > >>>>> Let me know if you see any other issues I missed with this approach.
> > > >>>> The problem here is that these drivers are now coupled together, and
> > > >>>> that should not be taken lightly. We have a dependency hell in our
> > > >>>> hands with a lot of drivers, and the culprit is always platform data.
> > > >>>>
> > > >>>> Build-in device properties may be messy, but I would still say they
> > > >>>> are less messy than those quirk flags - you got to admit, they are a
> > > >>>> mess. The benefit from build-in properties is in any case the fact
> > > >>>> that they remove the need to couple these drivers together.
> > > >>> Agree, quirk bits are messy. Any suggestion that would work with
> > > >>> PCI xHCI devices, devicetree, and "pure" platform devices?
> > > >> I think xHCI driver should always be able to rely on being able to
> > > >> read this kind of information from the fwnode. If there is no actual
> > > >> firmware node (DT or ACPI), or if it's missing some information, the
> > > >> glue driver needs to populate software node for the xHCI.
> > > >>
> > > >> Right now I just want to avoid having to pass the quirks using
> > > >> platform data from drivers such as drivers/usb/cdns3/host.c and
> > > >> drivers/usb/dwc3/host.c to xHCI.
> > > >>
> > > >> One way we could do that is by defining compatibility ID for both of
> > > >> them that we provide using a single device property (like I guess DT
> > > >> does). Then based on that compatibility ID, xhci-plat.c can set the
> > > >> actual "static" quirk flags. That we could already do easily. How
> > > >> would that sound to you?
> > > 
> > > Sounds good. 
> > > 
> > > > 
> > > > This was my previous patch where I was using device tree property. Should we go ahead with this approach?
> > > > 
> > > > https://patchwork.kernel.org/project/linux-arm-msm/cover/1636353710-25582-1-git-send-email-quic_c_sanm@quicinc.com/
> > > > 
> > > > Any further changes to this ?
> > > 
> > > By dropping the DT part of that series we get a similar built-in device property
> > > solution as Heikki initially suggested.
> > > 
> > > How about adding the compatibility ID device property that was just suggested?
> > > Then matching the Id in xhci-plat.c against a static table containing Ids and
> > > xhci_plat_priv structures, with the needed quirks for dwc3.
> > 
> > There was a comment from Pavan. Is it still possible to get this
> > detail from DT?
> > I guess that would still be ideal, right?
> > 
> I was suggesting if we can have device tree param like the patch sandeep
> pointed out.
> 
> How would adding a compatible index to usb_xhci_of_match[] would work
> actually? I ask this because, dwc3/host.c creates platform device and
> it is not associated with any of_node, so of_driver_match_device() called
> from platform bus match method does not work. one way to achieve this would
> be by matching against sysdev. Something like below. Is it acceptible?
> 
> diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
> index 649ffd8..bd5d055 100644
> --- a/drivers/usb/host/xhci-plat.c
> +++ b/drivers/usb/host/xhci-plat.c
> @@ -126,6 +126,10 @@ static const struct xhci_plat_priv xhci_plat_brcm = {
>  	.quirks = XHCI_RESET_ON_RESUME,
>  };
>  
> +static const struct xhci_plat_priv xhci_plat_dwc3 = {
> +	.quirks = XHCI_SKIP_PHY_INIT,
> +};
> +
>  static const struct of_device_id usb_xhci_of_match[] = {
>  	{
>  		.compatible = "generic-xhci",
> @@ -167,6 +171,9 @@ static const struct of_device_id usb_xhci_of_match[] = {
>  	}, {
>  		.compatible = "brcm,bcm7445-xhci",
>  		.data = &xhci_plat_brcm,
> +	}, {
> +		.compatible = "snps,dwc3",
> +		.data = &xhci_plat_dwc3,
>  	},
>  	{},
>  };
> @@ -274,6 +281,15 @@ static int xhci_plat_probe(struct platform_device *pdev)
>  	else
>  		priv_match = dev_get_platdata(&pdev->dev);
>  
> +	/* allow private data mapping with the sysdev compatible */
> +	if (!priv_match) {
> +		struct of_device_id *match;
> +
> +		match = of_match_device(usb_xhci_of_match, sysdev);
> +		if (match)
> +			priv_match = match->data;
> +	}
> +
>  	if (priv_match) {
>  		priv = hcd_to_xhci_priv(hcd);
>  		/* Just copy data for now */
> 
> > I have another question. Can't we now just assume that if the sysdev
> > is the parent (or grandparent), then the phy initialization should
> > always be skipped? In that case we could just do something like this:
> > 
> > diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
> > index 649ffd861b44e..1018b33488046 100644
> > --- a/drivers/usb/host/xhci-plat.c
> > +++ b/drivers/usb/host/xhci-plat.c
> > @@ -212,8 +212,12 @@ static int xhci_plat_probe(struct platform_device *pdev)
> >  #endif
> >         }
> >  
> > -       if (!sysdev)
> > +       if (sysdev) {
> > +               if (sysdev != &pdev->dev)
> > +                       hcd->skip_phy_initialization = 1;
> > +       } else {
> >                 sysdev = &pdev->dev;
> > +       }
> >  
> >         if (WARN_ON(!sysdev->dma_mask))
> >                 /* Platform did not initialize dma_mask */
> > 
> > 
> > I did not go through all the drivers that carefully, so I may have
> > missed something, but it looks like the only drivers that can have the
> > sysdev as the parent or grandparent are cdns3 and dwc3.
> > 
> I cross checked and these are two drivers that are creating xhci-plat device.
> So this patch would definitely work. However I am not sure in future if any
> device created via device tree would want to use this feature. For now,
> it looks good. It Mathias, Do you see any problem with this approach?
> 

Can you please provide your suggestions on this? We have discussed about
3 approaches here other than the whole platform data refactoring done.

(1) Introduce a new dT property and expect dwc3/host.c to set this property
to skip the phy initialization.
(2) Allow platform private data match based on the sysdev. The diff I sent
in the previous email.
(3) Heikki's suggestion of relying on the fact that the users of phy skip
init can be tested with sysdev != &pdev->dev check.

Thanks,
Pavan

Re: [PATCH v3 3/3] usb: dwc: host: add xhci_plat_priv quirk XHCI_SKIP_PHY_INIT

[Heikki Krogerus]

On Wed, Apr 06, 2022 at 11:55:43AM +0530, Pavan Kondeti wrote:
> Hi Heikki/Mathias,
> 
> On Mon, Apr 04, 2022 at 01:55:16PM +0530, Pavan Kondeti wrote:
> > Hi Heikki,
> > 
> > On Thu, Mar 31, 2022 at 02:16:53PM +0300, Heikki Krogerus wrote:
> > > On Wed, Mar 30, 2022 at 08:47:34PM +0300, Mathias Nyman wrote:
> > > > On 29.3.2022 12.18, Sandeep Maheswaram (Temp) wrote:
> > > > > Hi Mathias,Heikki
> > > > > 
> > > > > On 3/25/2022 9:08 PM, Heikki Krogerus wrote:
> > > > >> On Fri, Mar 25, 2022 at 04:33:27PM +0200, Mathias Nyman wrote:
> > > > >>> On 25.3.2022 13.27, Heikki Krogerus wrote:
> > > > >>>> On Fri, Mar 25, 2022 at 12:36:22AM +0200, Mathias Nyman wrote:
> > > > >>>>> On 24.3.2022 14.27, Heikki Krogerus wrote:
> > > > >>>>>> On Thu, Mar 24, 2022 at 12:07:11PM +0530, Sandeep Maheswaram wrote:
> > > > >>>>>>> Currently the phy init is done from dwc3 and also xhci which makes the
> > > > >>>>>>> runtime_usage value 2 for the phy which causes issue during runtime
> > > > >>>>>>> suspend. When we run the below command the runtime_status still shows
> > > > >>>>>>> active.
> > > > >>>>>>> echo auto > /sys/bus/platform/devices/88e3000.phy/power/control
> > > > >>>>>>>
> > > > >>>>>>> dwc3 manages PHY by own DRD driver, so skip the management by
> > > > >>>>>>> HCD core by setting this quirk.
> > > > >>>>>>>
> > > > >>>>>>> Signed-off-by: Sandeep Maheswaram <quic_c_sanm@quicinc.com>
> > > > >>>>>>> ---
> > > > >>>>>>>   drivers/usb/dwc3/host.c | 13 +++++++++++++
> > > > >>>>>>>   1 file changed, 13 insertions(+)
> > > > >>>>>>>
> > > > >>>>>>> diff --git a/drivers/usb/dwc3/host.c b/drivers/usb/dwc3/host.c
> > > > >>>>>>> index eda8719..d4fcf06 100644
> > > > >>>>>>> --- a/drivers/usb/dwc3/host.c
> > > > >>>>>>> +++ b/drivers/usb/dwc3/host.c
> > > > >>>>>>> @@ -13,6 +13,12 @@
> > > > >>>>>>>   #include <linux/platform_device.h>
> > > > >>>>>>>     #include "core.h"
> > > > >>>>>>> +#include <linux/usb/xhci-plat.h>
> > > > >>>>>>> +#include <linux/usb/xhci-quirks.h>
> > > > >>>>>>> +
> > > > >>>>>>> +static const struct xhci_plat_priv xhci_plat_dwc3_xhci = {
> > > > >>>>>>> +    .quirks = XHCI_SKIP_PHY_INIT,
> > > > >>>>>>> +};
> > > > >>>>>>>     static void dwc3_host_fill_xhci_irq_res(struct dwc3 *dwc,
> > > > >>>>>>>                       int irq, char *name)
> > > > >>>>>>> @@ -122,6 +128,13 @@ int dwc3_host_init(struct dwc3 *dwc)
> > > > >>>>>>>           }
> > > > >>>>>>>       }
> > > > >>>>>>>   +    ret = platform_device_add_data(xhci, &xhci_plat_dwc3_xhci,
> > > > >>>>>>> +            sizeof(xhci_plat_dwc3_xhci));
> > > > >>>>>>> +    if (ret) {
> > > > >>>>>>> +        dev_err(dwc->dev, "failed to add data to xHCI\n");
> > > > >>>>>>> +        goto err;
> > > > >>>>>>> +    }
> > > > >>>>>>> +
> > > > >>>>>>>       ret = platform_device_add(xhci);
> > > > >>>>>>>       if (ret) {
> > > > >>>>>>>           dev_err(dwc->dev, "failed to register xHCI device\n");
> > > > >>>>>> I think you should just use device property:
> > > > >>>>>>
> > > > >>>>> This was suggested in an earlier series, but was rejected as it also added
> > > > >>>>> the property as a device tree parameter.
> > > > >>>>>
> > > > >>>>> I think adding more device properties can be messy in the long run, especially if we
> > > > >>>>> need to add them for many of the existing xhci quirks.
> > > > >>>>> We also end up with a mix where some device properties are listed as device tree
> > > > >>>>> parameters, and some not.
> > > > >>>>>
> > > > >>>>> Defining xhci quirks and platform data structure in headers shared with dwc3 and cdns3
> > > > >>>>> allow those drivers to easily set any existing xhci quirk, or other possible optional
> > > > >>>>> callbacks.
> > > > >>>>>
> > > > >>>>> cdns3 driver is already doing this, but it includes the full xhci.h header.
> > > > >>>>> This series cleans up that a bit so cdns3 will only include xhci quirk bits and
> > > > >>>>> platform data structure.
> > > > >>>>>
> > > > >>>>> On the downside we add a couple xhci related header files to include/linux/usb/
> > > > >>>>> Let me know if you see any other issues I missed with this approach.
> > > > >>>> The problem here is that these drivers are now coupled together, and
> > > > >>>> that should not be taken lightly. We have a dependency hell in our
> > > > >>>> hands with a lot of drivers, and the culprit is always platform data.
> > > > >>>>
> > > > >>>> Build-in device properties may be messy, but I would still say they
> > > > >>>> are less messy than those quirk flags - you got to admit, they are a
> > > > >>>> mess. The benefit from build-in properties is in any case the fact
> > > > >>>> that they remove the need to couple these drivers together.
> > > > >>> Agree, quirk bits are messy. Any suggestion that would work with
> > > > >>> PCI xHCI devices, devicetree, and "pure" platform devices?
> > > > >> I think xHCI driver should always be able to rely on being able to
> > > > >> read this kind of information from the fwnode. If there is no actual
> > > > >> firmware node (DT or ACPI), or if it's missing some information, the
> > > > >> glue driver needs to populate software node for the xHCI.
> > > > >>
> > > > >> Right now I just want to avoid having to pass the quirks using
> > > > >> platform data from drivers such as drivers/usb/cdns3/host.c and
> > > > >> drivers/usb/dwc3/host.c to xHCI.
> > > > >>
> > > > >> One way we could do that is by defining compatibility ID for both of
> > > > >> them that we provide using a single device property (like I guess DT
> > > > >> does). Then based on that compatibility ID, xhci-plat.c can set the
> > > > >> actual "static" quirk flags. That we could already do easily. How
> > > > >> would that sound to you?
> > > > 
> > > > Sounds good. 
> > > > 
> > > > > 
> > > > > This was my previous patch where I was using device tree property. Should we go ahead with this approach?
> > > > > 
> > > > > https://patchwork.kernel.org/project/linux-arm-msm/cover/1636353710-25582-1-git-send-email-quic_c_sanm@quicinc.com/
> > > > > 
> > > > > Any further changes to this ?
> > > > 
> > > > By dropping the DT part of that series we get a similar built-in device property
> > > > solution as Heikki initially suggested.
> > > > 
> > > > How about adding the compatibility ID device property that was just suggested?
> > > > Then matching the Id in xhci-plat.c against a static table containing Ids and
> > > > xhci_plat_priv structures, with the needed quirks for dwc3.
> > > 
> > > There was a comment from Pavan. Is it still possible to get this
> > > detail from DT?
> > > I guess that would still be ideal, right?
> > > 
> > I was suggesting if we can have device tree param like the patch sandeep
> > pointed out.
> > 
> > How would adding a compatible index to usb_xhci_of_match[] would work
> > actually? I ask this because, dwc3/host.c creates platform device and
> > it is not associated with any of_node, so of_driver_match_device() called
> > from platform bus match method does not work. one way to achieve this would
> > be by matching against sysdev. Something like below. Is it acceptible?
> > 
> > diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
> > index 649ffd8..bd5d055 100644
> > --- a/drivers/usb/host/xhci-plat.c
> > +++ b/drivers/usb/host/xhci-plat.c
> > @@ -126,6 +126,10 @@ static const struct xhci_plat_priv xhci_plat_brcm = {
> >  	.quirks = XHCI_RESET_ON_RESUME,
> >  };
> >  
> > +static const struct xhci_plat_priv xhci_plat_dwc3 = {
> > +	.quirks = XHCI_SKIP_PHY_INIT,
> > +};
> > +
> >  static const struct of_device_id usb_xhci_of_match[] = {
> >  	{
> >  		.compatible = "generic-xhci",
> > @@ -167,6 +171,9 @@ static const struct of_device_id usb_xhci_of_match[] = {
> >  	}, {
> >  		.compatible = "brcm,bcm7445-xhci",
> >  		.data = &xhci_plat_brcm,
> > +	}, {
> > +		.compatible = "snps,dwc3",
> > +		.data = &xhci_plat_dwc3,
> >  	},
> >  	{},
> >  };
> > @@ -274,6 +281,15 @@ static int xhci_plat_probe(struct platform_device *pdev)
> >  	else
> >  		priv_match = dev_get_platdata(&pdev->dev);
> >  
> > +	/* allow private data mapping with the sysdev compatible */
> > +	if (!priv_match) {
> > +		struct of_device_id *match;
> > +
> > +		match = of_match_device(usb_xhci_of_match, sysdev);
> > +		if (match)
> > +			priv_match = match->data;
> > +	}
> > +
> >  	if (priv_match) {
> >  		priv = hcd_to_xhci_priv(hcd);
> >  		/* Just copy data for now */
> > 
> > > I have another question. Can't we now just assume that if the sysdev
> > > is the parent (or grandparent), then the phy initialization should
> > > always be skipped? In that case we could just do something like this:
> > > 
> > > diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
> > > index 649ffd861b44e..1018b33488046 100644
> > > --- a/drivers/usb/host/xhci-plat.c
> > > +++ b/drivers/usb/host/xhci-plat.c
> > > @@ -212,8 +212,12 @@ static int xhci_plat_probe(struct platform_device *pdev)
> > >  #endif
> > >         }
> > >  
> > > -       if (!sysdev)
> > > +       if (sysdev) {
> > > +               if (sysdev != &pdev->dev)
> > > +                       hcd->skip_phy_initialization = 1;
> > > +       } else {
> > >                 sysdev = &pdev->dev;
> > > +       }
> > >  
> > >         if (WARN_ON(!sysdev->dma_mask))
> > >                 /* Platform did not initialize dma_mask */
> > > 
> > > 
> > > I did not go through all the drivers that carefully, so I may have
> > > missed something, but it looks like the only drivers that can have the
> > > sysdev as the parent or grandparent are cdns3 and dwc3.
> > > 
> > I cross checked and these are two drivers that are creating xhci-plat device.
> > So this patch would definitely work. However I am not sure in future if any
> > device created via device tree would want to use this feature. For now,
> > it looks good. It Mathias, Do you see any problem with this approach?
> > 
> 
> Can you please provide your suggestions on this? We have discussed about
> 3 approaches here other than the whole platform data refactoring done.
> 
> (1) Introduce a new dT property and expect dwc3/host.c to set this property
> to skip the phy initialization.
> (2) Allow platform private data match based on the sysdev. The diff I sent
> in the previous email.
> (3) Heikki's suggestion of relying on the fact that the users of phy skip
> init can be tested with sysdev != &pdev->dev check.

My vote is for option 3. That would allow us to sort this out properly
later. I will in any case look at these drivers when I send the
software node PM operations patch series.

thanks,

-- 
heikki

Re: [PATCH v3 3/3] usb: dwc: host: add xhci_plat_priv quirk XHCI_SKIP_PHY_INIT

[Mathias Nyman]

Hi

Sorry about the delayed response.


On 6.4.2022 9.25, Pavan Kondeti wrote:
> Hi Heikki/Mathias,
> 
> On Mon, Apr 04, 2022 at 01:55:16PM +0530, Pavan Kondeti wrote:
>> Hi Heikki,
>>
>> On Thu, Mar 31, 2022 at 02:16:53PM +0300, Heikki Krogerus wrote:
>>> On Wed, Mar 30, 2022 at 08:47:34PM +0300, Mathias Nyman wrote:
>>>> On 29.3.2022 12.18, Sandeep Maheswaram (Temp) wrote:
>>>>> Hi Mathias,Heikki
>>>>>
>>>>> On 3/25/2022 9:08 PM, Heikki Krogerus wrote:
>>>>>> On Fri, Mar 25, 2022 at 04:33:27PM +0200, Mathias Nyman wrote:
>>>>>>> On 25.3.2022 13.27, Heikki Krogerus wrote:
>>>>>>>> On Fri, Mar 25, 2022 at 12:36:22AM +0200, Mathias Nyman wrote:
>>>>>>>>> On 24.3.2022 14.27, Heikki Krogerus wrote:
>>>>>>>>>> On Thu, Mar 24, 2022 at 12:07:11PM +0530, Sandeep Maheswaram wrote:
>>>>>>>>>>> Currently the phy init is done from dwc3 and also xhci which makes the
>>>>>>>>>>> runtime_usage value 2 for the phy which causes issue during runtime
>>>>>>>>>>> suspend. When we run the below command the runtime_status still shows
>>>>>>>>>>> active.
>>>>>>>>>>> echo auto > /sys/bus/platform/devices/88e3000.phy/power/control
>>>>>>>>>>>
>>>>>>>>>>> dwc3 manages PHY by own DRD driver, so skip the management by
>>>>>>>>>>> HCD core by setting this quirk.
>>>>>>>>>>>
>>>>>>>>>>> Signed-off-by: Sandeep Maheswaram <quic_c_sanm@quicinc.com>
>>>>>>>>>>> ---
>>>>>>>>>>>   drivers/usb/dwc3/host.c | 13 +++++++++++++
>>>>>>>>>>>   1 file changed, 13 insertions(+)
>>>>>>>>>>>
>>>>>>>>>>> diff --git a/drivers/usb/dwc3/host.c b/drivers/usb/dwc3/host.c
>>>>>>>>>>> index eda8719..d4fcf06 100644
>>>>>>>>>>> --- a/drivers/usb/dwc3/host.c
>>>>>>>>>>> +++ b/drivers/usb/dwc3/host.c
>>>>>>>>>>> @@ -13,6 +13,12 @@
>>>>>>>>>>>   #include <linux/platform_device.h>
>>>>>>>>>>>     #include "core.h"
>>>>>>>>>>> +#include <linux/usb/xhci-plat.h>
>>>>>>>>>>> +#include <linux/usb/xhci-quirks.h>
>>>>>>>>>>> +
>>>>>>>>>>> +static const struct xhci_plat_priv xhci_plat_dwc3_xhci = {
>>>>>>>>>>> +    .quirks = XHCI_SKIP_PHY_INIT,
>>>>>>>>>>> +};
>>>>>>>>>>>     static void dwc3_host_fill_xhci_irq_res(struct dwc3 *dwc,
>>>>>>>>>>>                       int irq, char *name)
>>>>>>>>>>> @@ -122,6 +128,13 @@ int dwc3_host_init(struct dwc3 *dwc)
>>>>>>>>>>>           }
>>>>>>>>>>>       }
>>>>>>>>>>>   +    ret = platform_device_add_data(xhci, &xhci_plat_dwc3_xhci,
>>>>>>>>>>> +            sizeof(xhci_plat_dwc3_xhci));
>>>>>>>>>>> +    if (ret) {
>>>>>>>>>>> +        dev_err(dwc->dev, "failed to add data to xHCI\n");
>>>>>>>>>>> +        goto err;
>>>>>>>>>>> +    }
>>>>>>>>>>> +
>>>>>>>>>>>       ret = platform_device_add(xhci);
>>>>>>>>>>>       if (ret) {
>>>>>>>>>>>           dev_err(dwc->dev, "failed to register xHCI device\n");
>>>>>>>>>> I think you should just use device property:
>>>>>>>>>>
>>>>>>>>> This was suggested in an earlier series, but was rejected as it also added
>>>>>>>>> the property as a device tree parameter.
>>>>>>>>>
>>>>>>>>> I think adding more device properties can be messy in the long run, especially if we
>>>>>>>>> need to add them for many of the existing xhci quirks.
>>>>>>>>> We also end up with a mix where some device properties are listed as device tree
>>>>>>>>> parameters, and some not.
>>>>>>>>>
>>>>>>>>> Defining xhci quirks and platform data structure in headers shared with dwc3 and cdns3
>>>>>>>>> allow those drivers to easily set any existing xhci quirk, or other possible optional
>>>>>>>>> callbacks.
>>>>>>>>>
>>>>>>>>> cdns3 driver is already doing this, but it includes the full xhci.h header.
>>>>>>>>> This series cleans up that a bit so cdns3 will only include xhci quirk bits and
>>>>>>>>> platform data structure.
>>>>>>>>>
>>>>>>>>> On the downside we add a couple xhci related header files to include/linux/usb/
>>>>>>>>> Let me know if you see any other issues I missed with this approach.
>>>>>>>> The problem here is that these drivers are now coupled together, and
>>>>>>>> that should not be taken lightly. We have a dependency hell in our
>>>>>>>> hands with a lot of drivers, and the culprit is always platform data.
>>>>>>>>
>>>>>>>> Build-in device properties may be messy, but I would still say they
>>>>>>>> are less messy than those quirk flags - you got to admit, they are a
>>>>>>>> mess. The benefit from build-in properties is in any case the fact
>>>>>>>> that they remove the need to couple these drivers together.
>>>>>>> Agree, quirk bits are messy. Any suggestion that would work with
>>>>>>> PCI xHCI devices, devicetree, and "pure" platform devices?
>>>>>> I think xHCI driver should always be able to rely on being able to
>>>>>> read this kind of information from the fwnode. If there is no actual
>>>>>> firmware node (DT or ACPI), or if it's missing some information, the
>>>>>> glue driver needs to populate software node for the xHCI.
>>>>>>
>>>>>> Right now I just want to avoid having to pass the quirks using
>>>>>> platform data from drivers such as drivers/usb/cdns3/host.c and
>>>>>> drivers/usb/dwc3/host.c to xHCI.
>>>>>>
>>>>>> One way we could do that is by defining compatibility ID for both of
>>>>>> them that we provide using a single device property (like I guess DT
>>>>>> does). Then based on that compatibility ID, xhci-plat.c can set the
>>>>>> actual "static" quirk flags. That we could already do easily. How
>>>>>> would that sound to you?
>>>>
>>>> Sounds good. 
>>>>
>>>>>
>>>>> This was my previous patch where I was using device tree property. Should we go ahead with this approach?
>>>>>
>>>>> https://patchwork.kernel.org/project/linux-arm-msm/cover/1636353710-25582-1-git-send-email-quic_c_sanm@quicinc.com/
>>>>>
>>>>> Any further changes to this ?
>>>>
>>>> By dropping the DT part of that series we get a similar built-in device property
>>>> solution as Heikki initially suggested.
>>>>
>>>> How about adding the compatibility ID device property that was just suggested?
>>>> Then matching the Id in xhci-plat.c against a static table containing Ids and
>>>> xhci_plat_priv structures, with the needed quirks for dwc3.
>>>
>>> There was a comment from Pavan. Is it still possible to get this
>>> detail from DT?
>>> I guess that would still be ideal, right?
>>>
>> I was suggesting if we can have device tree param like the patch sandeep
>> pointed out.
>>
>> How would adding a compatible index to usb_xhci_of_match[] would work
>> actually? I ask this because, dwc3/host.c creates platform device and
>> it is not associated with any of_node, so of_driver_match_device() called
>> from platform bus match method does not work. one way to achieve this would
>> be by matching against sysdev. Something like below. Is it acceptible?
>>
>> diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
>> index 649ffd8..bd5d055 100644
>> --- a/drivers/usb/host/xhci-plat.c
>> +++ b/drivers/usb/host/xhci-plat.c
>> @@ -126,6 +126,10 @@ static const struct xhci_plat_priv xhci_plat_brcm = {
>>  	.quirks = XHCI_RESET_ON_RESUME,
>>  };
>>  
>> +static const struct xhci_plat_priv xhci_plat_dwc3 = {
>> +	.quirks = XHCI_SKIP_PHY_INIT,
>> +};
>> +
>>  static const struct of_device_id usb_xhci_of_match[] = {
>>  	{
>>  		.compatible = "generic-xhci",
>> @@ -167,6 +171,9 @@ static const struct of_device_id usb_xhci_of_match[] = {
>>  	}, {
>>  		.compatible = "brcm,bcm7445-xhci",
>>  		.data = &xhci_plat_brcm,
>> +	}, {
>> +		.compatible = "snps,dwc3",
>> +		.data = &xhci_plat_dwc3,
>>  	},

Isn't there a risk that xhci-plat now binds to the parent dwc3 device?
competing with the similar of_match_table entry created in drivers/usb/dwc3/core.c

>>  	{},
>>  };
>> @@ -274,6 +281,15 @@ static int xhci_plat_probe(struct platform_device *pdev)
>>  	else
>>  		priv_match = dev_get_platdata(&pdev->dev);
>>  
>> +	/* allow private data mapping with the sysdev compatible */
>> +	if (!priv_match) {
>> +		struct of_device_id *match;
>> +
>> +		match = of_match_device(usb_xhci_of_match, sysdev);
>> +		if (match)
>> +			priv_match = match->data;
>> +	}
>> +
>>  	if (priv_match) {
>>  		priv = hcd_to_xhci_priv(hcd);
>>  		/* Just copy data for now */
>>
>>> I have another question. Can't we now just assume that if the sysdev
>>> is the parent (or grandparent), then the phy initialization should
>>> always be skipped? In that case we could just do something like this:
>>>
>>> diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
>>> index 649ffd861b44e..1018b33488046 100644
>>> --- a/drivers/usb/host/xhci-plat.c
>>> +++ b/drivers/usb/host/xhci-plat.c
>>> @@ -212,8 +212,12 @@ static int xhci_plat_probe(struct platform_device *pdev)
>>>  #endif
>>>         }
>>>  
>>> -       if (!sysdev)
>>> +       if (sysdev) {
>>> +               if (sysdev != &pdev->dev)
>>> +                       hcd->skip_phy_initialization = 1;
>>> +       } else {
>>>                 sysdev = &pdev->dev;
>>> +       }
>>>  
>>>         if (WARN_ON(!sysdev->dma_mask))
>>>                 /* Platform did not initialize dma_mask */
>>>
>>>
>>> I did not go through all the drivers that carefully, so I may have
>>> missed something, but it looks like the only drivers that can have the
>>> sysdev as the parent or grandparent are cdns3 and dwc3.
>>>
>> I cross checked and these are two drivers that are creating xhci-plat device.
>> So this patch would definitely work. However I am not sure in future if any
>> device created via device tree would want to use this feature. For now,
>> it looks good. It Mathias, Do you see any problem with this approach?
>>

Would work for now but seems like a risk to assume this would hold for all future
xhci platform devices. 

> 
> Can you please provide your suggestions on this? We have discussed about
> 3 approaches here other than the whole platform data refactoring done.
> 
> (1) Introduce a new dT property and expect dwc3/host.c to set this property
> to skip the phy initialization.

Adding one more device property to swnode in dwc3/host.c starts
to look like the best option for now even if it didn't appeal initially.

The place creating the xhci platform device should have best info on what properties
are needed for the platform device.

So this would be just like Heikki's first suggestion, or Sandeep's patches 2/3 and 3/3 in:
https://patchwork.kernel.org/project/linux-arm-msm/cover/1636353710-25582-1-git-send-email-quic_c_sanm@quicinc.com/
but without the devicetree binding documentation part.

> (2) Allow platform private data match based on the sysdev. The diff I sent
> in the previous email
-Possible risk of binding parent dwc3 to incorrect driver (xhci-plat), haven't looked at details.
-Not working with ACPI dwc3 devices.

Basic idea was similar to what I was thinking, but not matching with sysdev and
misusing the of of_device_id table. Instead create a device property similar
to "compatible".  But looks like we would need to reinvent the wheel and create
a some kind of swnode_device_id table, and custom match functions.
So option 1 looks better to get this case fixed

> (3) Heikki's suggestion of relying on the fact that the users of phy skip
> init can be tested with sysdev != &pdev->dev check.

Looks like a risky assumption for future, but could work as temporary solution
 
So I think option 1 looks best, option 3 possible

I also realize I don't know details of of_node, fwnode, swnode and device properties so
all comments from Heikki and other who know more about this are welcome.

Thanks
-Mathias

Re: [PATCH v3 3/3] usb: dwc: host: add xhci_plat_priv quirk XHCI_SKIP_PHY_INIT

[Pavan Kondeti]

Hi Mathias,

On Wed, Apr 06, 2022 at 01:52:56PM +0300, Mathias Nyman wrote:
> Hi
> 
> Sorry about the delayed response.
> 
> 
> On 6.4.2022 9.25, Pavan Kondeti wrote:
> > Hi Heikki/Mathias,
> > 
> > On Mon, Apr 04, 2022 at 01:55:16PM +0530, Pavan Kondeti wrote:
> >> Hi Heikki,
> >>
> >> On Thu, Mar 31, 2022 at 02:16:53PM +0300, Heikki Krogerus wrote:
> >>> On Wed, Mar 30, 2022 at 08:47:34PM +0300, Mathias Nyman wrote:
> >>>> On 29.3.2022 12.18, Sandeep Maheswaram (Temp) wrote:
> >>>>> Hi Mathias,Heikki
> >>>>>
> >>>>> On 3/25/2022 9:08 PM, Heikki Krogerus wrote:
> >>>>>> On Fri, Mar 25, 2022 at 04:33:27PM +0200, Mathias Nyman wrote:
> >>>>>>> On 25.3.2022 13.27, Heikki Krogerus wrote:
> >>>>>>>> On Fri, Mar 25, 2022 at 12:36:22AM +0200, Mathias Nyman wrote:
> >>>>>>>>> On 24.3.2022 14.27, Heikki Krogerus wrote:
> >>>>>>>>>> On Thu, Mar 24, 2022 at 12:07:11PM +0530, Sandeep Maheswaram wrote:
> >>>>>>>>>>> Currently the phy init is done from dwc3 and also xhci which makes the
> >>>>>>>>>>> runtime_usage value 2 for the phy which causes issue during runtime
> >>>>>>>>>>> suspend. When we run the below command the runtime_status still shows
> >>>>>>>>>>> active.
> >>>>>>>>>>> echo auto > /sys/bus/platform/devices/88e3000.phy/power/control
> >>>>>>>>>>>
> >>>>>>>>>>> dwc3 manages PHY by own DRD driver, so skip the management by
> >>>>>>>>>>> HCD core by setting this quirk.
> >>>>>>>>>>>
> >>>>>>>>>>> Signed-off-by: Sandeep Maheswaram <quic_c_sanm@quicinc.com>
> >>>>>>>>>>> ---
> >>>>>>>>>>>   drivers/usb/dwc3/host.c | 13 +++++++++++++
> >>>>>>>>>>>   1 file changed, 13 insertions(+)
> >>>>>>>>>>>
> >>>>>>>>>>> diff --git a/drivers/usb/dwc3/host.c b/drivers/usb/dwc3/host.c
> >>>>>>>>>>> index eda8719..d4fcf06 100644
> >>>>>>>>>>> --- a/drivers/usb/dwc3/host.c
> >>>>>>>>>>> +++ b/drivers/usb/dwc3/host.c
> >>>>>>>>>>> @@ -13,6 +13,12 @@
> >>>>>>>>>>>   #include <linux/platform_device.h>
> >>>>>>>>>>>     #include "core.h"
> >>>>>>>>>>> +#include <linux/usb/xhci-plat.h>
> >>>>>>>>>>> +#include <linux/usb/xhci-quirks.h>
> >>>>>>>>>>> +
> >>>>>>>>>>> +static const struct xhci_plat_priv xhci_plat_dwc3_xhci = {
> >>>>>>>>>>> +    .quirks = XHCI_SKIP_PHY_INIT,
> >>>>>>>>>>> +};
> >>>>>>>>>>>     static void dwc3_host_fill_xhci_irq_res(struct dwc3 *dwc,
> >>>>>>>>>>>                       int irq, char *name)
> >>>>>>>>>>> @@ -122,6 +128,13 @@ int dwc3_host_init(struct dwc3 *dwc)
> >>>>>>>>>>>           }
> >>>>>>>>>>>       }
> >>>>>>>>>>>   +    ret = platform_device_add_data(xhci, &xhci_plat_dwc3_xhci,
> >>>>>>>>>>> +            sizeof(xhci_plat_dwc3_xhci));
> >>>>>>>>>>> +    if (ret) {
> >>>>>>>>>>> +        dev_err(dwc->dev, "failed to add data to xHCI\n");
> >>>>>>>>>>> +        goto err;
> >>>>>>>>>>> +    }
> >>>>>>>>>>> +
> >>>>>>>>>>>       ret = platform_device_add(xhci);
> >>>>>>>>>>>       if (ret) {
> >>>>>>>>>>>           dev_err(dwc->dev, "failed to register xHCI device\n");
> >>>>>>>>>> I think you should just use device property:
> >>>>>>>>>>
> >>>>>>>>> This was suggested in an earlier series, but was rejected as it also added
> >>>>>>>>> the property as a device tree parameter.
> >>>>>>>>>
> >>>>>>>>> I think adding more device properties can be messy in the long run, especially if we
> >>>>>>>>> need to add them for many of the existing xhci quirks.
> >>>>>>>>> We also end up with a mix where some device properties are listed as device tree
> >>>>>>>>> parameters, and some not.
> >>>>>>>>>
> >>>>>>>>> Defining xhci quirks and platform data structure in headers shared with dwc3 and cdns3
> >>>>>>>>> allow those drivers to easily set any existing xhci quirk, or other possible optional
> >>>>>>>>> callbacks.
> >>>>>>>>>
> >>>>>>>>> cdns3 driver is already doing this, but it includes the full xhci.h header.
> >>>>>>>>> This series cleans up that a bit so cdns3 will only include xhci quirk bits and
> >>>>>>>>> platform data structure.
> >>>>>>>>>
> >>>>>>>>> On the downside we add a couple xhci related header files to include/linux/usb/
> >>>>>>>>> Let me know if you see any other issues I missed with this approach.
> >>>>>>>> The problem here is that these drivers are now coupled together, and
> >>>>>>>> that should not be taken lightly. We have a dependency hell in our
> >>>>>>>> hands with a lot of drivers, and the culprit is always platform data.
> >>>>>>>>
> >>>>>>>> Build-in device properties may be messy, but I would still say they
> >>>>>>>> are less messy than those quirk flags - you got to admit, they are a
> >>>>>>>> mess. The benefit from build-in properties is in any case the fact
> >>>>>>>> that they remove the need to couple these drivers together.
> >>>>>>> Agree, quirk bits are messy. Any suggestion that would work with
> >>>>>>> PCI xHCI devices, devicetree, and "pure" platform devices?
> >>>>>> I think xHCI driver should always be able to rely on being able to
> >>>>>> read this kind of information from the fwnode. If there is no actual
> >>>>>> firmware node (DT or ACPI), or if it's missing some information, the
> >>>>>> glue driver needs to populate software node for the xHCI.
> >>>>>>
> >>>>>> Right now I just want to avoid having to pass the quirks using
> >>>>>> platform data from drivers such as drivers/usb/cdns3/host.c and
> >>>>>> drivers/usb/dwc3/host.c to xHCI.
> >>>>>>
> >>>>>> One way we could do that is by defining compatibility ID for both of
> >>>>>> them that we provide using a single device property (like I guess DT
> >>>>>> does). Then based on that compatibility ID, xhci-plat.c can set the
> >>>>>> actual "static" quirk flags. That we could already do easily. How
> >>>>>> would that sound to you?
> >>>>
> >>>> Sounds good. 
> >>>>
> >>>>>
> >>>>> This was my previous patch where I was using device tree property. Should we go ahead with this approach?
> >>>>>
> >>>>> https://patchwork.kernel.org/project/linux-arm-msm/cover/1636353710-25582-1-git-send-email-quic_c_sanm@quicinc.com/
> >>>>>
> >>>>> Any further changes to this ?
> >>>>
> >>>> By dropping the DT part of that series we get a similar built-in device property
> >>>> solution as Heikki initially suggested.
> >>>>
> >>>> How about adding the compatibility ID device property that was just suggested?
> >>>> Then matching the Id in xhci-plat.c against a static table containing Ids and
> >>>> xhci_plat_priv structures, with the needed quirks for dwc3.
> >>>
> >>> There was a comment from Pavan. Is it still possible to get this
> >>> detail from DT?
> >>> I guess that would still be ideal, right?
> >>>
> >> I was suggesting if we can have device tree param like the patch sandeep
> >> pointed out.
> >>
> >> How would adding a compatible index to usb_xhci_of_match[] would work
> >> actually? I ask this because, dwc3/host.c creates platform device and
> >> it is not associated with any of_node, so of_driver_match_device() called
> >> from platform bus match method does not work. one way to achieve this would
> >> be by matching against sysdev. Something like below. Is it acceptible?
> >>
> >> diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
> >> index 649ffd8..bd5d055 100644
> >> --- a/drivers/usb/host/xhci-plat.c
> >> +++ b/drivers/usb/host/xhci-plat.c
> >> @@ -126,6 +126,10 @@ static const struct xhci_plat_priv xhci_plat_brcm = {
> >>  	.quirks = XHCI_RESET_ON_RESUME,
> >>  };
> >>  
> >> +static const struct xhci_plat_priv xhci_plat_dwc3 = {
> >> +	.quirks = XHCI_SKIP_PHY_INIT,
> >> +};
> >> +
> >>  static const struct of_device_id usb_xhci_of_match[] = {
> >>  	{
> >>  		.compatible = "generic-xhci",
> >> @@ -167,6 +171,9 @@ static const struct of_device_id usb_xhci_of_match[] = {
> >>  	}, {
> >>  		.compatible = "brcm,bcm7445-xhci",
> >>  		.data = &xhci_plat_brcm,
> >> +	}, {
> >> +		.compatible = "snps,dwc3",
> >> +		.data = &xhci_plat_dwc3,
> >>  	},
> 
> Isn't there a risk that xhci-plat now binds to the parent dwc3 device?
> competing with the similar of_match_table entry created in drivers/usb/dwc3/core.c

Sill of me. Yes, it does not work. Thanks for pointing it out.

> 
> >>  	{},
> >>  };
> >> @@ -274,6 +281,15 @@ static int xhci_plat_probe(struct platform_device *pdev)
> >>  	else
> >>  		priv_match = dev_get_platdata(&pdev->dev);
> >>  
> >> +	/* allow private data mapping with the sysdev compatible */
> >> +	if (!priv_match) {
> >> +		struct of_device_id *match;
> >> +
> >> +		match = of_match_device(usb_xhci_of_match, sysdev);
> >> +		if (match)
> >> +			priv_match = match->data;
> >> +	}
> >> +
> >>  	if (priv_match) {
> >>  		priv = hcd_to_xhci_priv(hcd);
> >>  		/* Just copy data for now */
> >>
> >>> I have another question. Can't we now just assume that if the sysdev
> >>> is the parent (or grandparent), then the phy initialization should
> >>> always be skipped? In that case we could just do something like this:
> >>>
> >>> diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
> >>> index 649ffd861b44e..1018b33488046 100644
> >>> --- a/drivers/usb/host/xhci-plat.c
> >>> +++ b/drivers/usb/host/xhci-plat.c
> >>> @@ -212,8 +212,12 @@ static int xhci_plat_probe(struct platform_device *pdev)
> >>>  #endif
> >>>         }
> >>>  
> >>> -       if (!sysdev)
> >>> +       if (sysdev) {
> >>> +               if (sysdev != &pdev->dev)
> >>> +                       hcd->skip_phy_initialization = 1;
> >>> +       } else {
> >>>                 sysdev = &pdev->dev;
> >>> +       }
> >>>  
> >>>         if (WARN_ON(!sysdev->dma_mask))
> >>>                 /* Platform did not initialize dma_mask */
> >>>
> >>>
> >>> I did not go through all the drivers that carefully, so I may have
> >>> missed something, but it looks like the only drivers that can have the
> >>> sysdev as the parent or grandparent are cdns3 and dwc3.
> >>>
> >> I cross checked and these are two drivers that are creating xhci-plat device.
> >> So this patch would definitely work. However I am not sure in future if any
> >> device created via device tree would want to use this feature. For now,
> >> it looks good. It Mathias, Do you see any problem with this approach?
> >>
> 
> Would work for now but seems like a risk to assume this would hold for all future
> xhci platform devices. 
> 
Agree that it may break in future for other drivers.

> > 
> > Can you please provide your suggestions on this? We have discussed about
> > 3 approaches here other than the whole platform data refactoring done.
> > 
> > (1) Introduce a new dT property and expect dwc3/host.c to set this property
> > to skip the phy initialization.
> 
> Adding one more device property to swnode in dwc3/host.c starts
> to look like the best option for now even if it didn't appeal initially.
> 
> The place creating the xhci platform device should have best info on what properties
> are needed for the platform device.
> 
> So this would be just like Heikki's first suggestion, or Sandeep's patches 2/3 and 3/3 in:
> https://patchwork.kernel.org/project/linux-arm-msm/cover/1636353710-25582-1-git-send-email-quic_c_sanm@quicinc.com/
> but without the devicetree binding documentation part.
> 
Why do you say devicetree binding doc is not needed in this case? Possible
that xhci-plat's device can be coming from dT and this param is passed to
skip initialization of PHY.

Thanks,
Pavan

Re: [PATCH v3 3/3] usb: dwc: host: add xhci_plat_priv quirk XHCI_SKIP_PHY_INIT

[Mathias Nyman]

On 6.4.2022 14.01, Pavan Kondeti wrote:
> Hi Mathias,
> 
> On Wed, Apr 06, 2022 at 01:52:56PM +0300, Mathias Nyman wrote:
>> Hi
>>
>> Sorry about the delayed response.
>>
>>
>> On 6.4.2022 9.25, Pavan Kondeti wrote:
>>> Hi Heikki/Mathias,
>>>
>>> On Mon, Apr 04, 2022 at 01:55:16PM +0530, Pavan Kondeti wrote:
>>>> Hi Heikki,
>>>>
>>>> On Thu, Mar 31, 2022 at 02:16:53PM +0300, Heikki Krogerus wrote:
>>>>> On Wed, Mar 30, 2022 at 08:47:34PM +0300, Mathias Nyman wrote:
>>>>>> On 29.3.2022 12.18, Sandeep Maheswaram (Temp) wrote:
>>>>>>> Hi Mathias,Heikki
>>>>>>>
>>>>>>> On 3/25/2022 9:08 PM, Heikki Krogerus wrote:
>>>>>>>> On Fri, Mar 25, 2022 at 04:33:27PM +0200, Mathias Nyman wrote:
>>>>>>>>> On 25.3.2022 13.27, Heikki Krogerus wrote:
>>>>>>>>>> On Fri, Mar 25, 2022 at 12:36:22AM +0200, Mathias Nyman wrote:
>>>>>>>>>>> On 24.3.2022 14.27, Heikki Krogerus wrote:
>>>>>>>>>>>> On Thu, Mar 24, 2022 at 12:07:11PM +0530, Sandeep Maheswaram wrote:
>>>>>>>>>>>>> Currently the phy init is done from dwc3 and also xhci which makes the
>>>>>>>>>>>>> runtime_usage value 2 for the phy which causes issue during runtime
>>>>>>>>>>>>> suspend. When we run the below command the runtime_status still shows
>>>>>>>>>>>>> active.
>>>>>>>>>>>>> echo auto > /sys/bus/platform/devices/88e3000.phy/power/control
>>>>>>>>>>>>>
>>>>>>>>>>>>> dwc3 manages PHY by own DRD driver, so skip the management by
>>>>>>>>>>>>> HCD core by setting this quirk.
>>>>>>>>>>>>>
>>>>>>>>>>>>> Signed-off-by: Sandeep Maheswaram <quic_c_sanm@quicinc.com>
>>>>>>>>>>>>> ---
>>>>>>>>>>>>>   drivers/usb/dwc3/host.c | 13 +++++++++++++
>>>>>>>>>>>>>   1 file changed, 13 insertions(+)
>>>>>>>>>>>>>
>>>>>>>>>>>>> diff --git a/drivers/usb/dwc3/host.c b/drivers/usb/dwc3/host.c
>>>>>>>>>>>>> index eda8719..d4fcf06 100644
>>>>>>>>>>>>> --- a/drivers/usb/dwc3/host.c
>>>>>>>>>>>>> +++ b/drivers/usb/dwc3/host.c
>>>>>>>>>>>>> @@ -13,6 +13,12 @@
>>>>>>>>>>>>>   #include <linux/platform_device.h>
>>>>>>>>>>>>>     #include "core.h"
>>>>>>>>>>>>> +#include <linux/usb/xhci-plat.h>
>>>>>>>>>>>>> +#include <linux/usb/xhci-quirks.h>
>>>>>>>>>>>>> +
>>>>>>>>>>>>> +static const struct xhci_plat_priv xhci_plat_dwc3_xhci = {
>>>>>>>>>>>>> +    .quirks = XHCI_SKIP_PHY_INIT,
>>>>>>>>>>>>> +};
>>>>>>>>>>>>>     static void dwc3_host_fill_xhci_irq_res(struct dwc3 *dwc,
>>>>>>>>>>>>>                       int irq, char *name)
>>>>>>>>>>>>> @@ -122,6 +128,13 @@ int dwc3_host_init(struct dwc3 *dwc)
>>>>>>>>>>>>>           }
>>>>>>>>>>>>>       }
>>>>>>>>>>>>>   +    ret = platform_device_add_data(xhci, &xhci_plat_dwc3_xhci,
>>>>>>>>>>>>> +            sizeof(xhci_plat_dwc3_xhci));
>>>>>>>>>>>>> +    if (ret) {
>>>>>>>>>>>>> +        dev_err(dwc->dev, "failed to add data to xHCI\n");
>>>>>>>>>>>>> +        goto err;
>>>>>>>>>>>>> +    }
>>>>>>>>>>>>> +
>>>>>>>>>>>>>       ret = platform_device_add(xhci);
>>>>>>>>>>>>>       if (ret) {
>>>>>>>>>>>>>           dev_err(dwc->dev, "failed to register xHCI device\n");
>>>>>>>>>>>> I think you should just use device property:
>>>>>>>>>>>>
>>>>>>>>>>> This was suggested in an earlier series, but was rejected as it also added
>>>>>>>>>>> the property as a device tree parameter.
>>>>>>>>>>>
>>>>>>>>>>> I think adding more device properties can be messy in the long run, especially if we
>>>>>>>>>>> need to add them for many of the existing xhci quirks.
>>>>>>>>>>> We also end up with a mix where some device properties are listed as device tree
>>>>>>>>>>> parameters, and some not.
>>>>>>>>>>>
>>>>>>>>>>> Defining xhci quirks and platform data structure in headers shared with dwc3 and cdns3
>>>>>>>>>>> allow those drivers to easily set any existing xhci quirk, or other possible optional
>>>>>>>>>>> callbacks.
>>>>>>>>>>>
>>>>>>>>>>> cdns3 driver is already doing this, but it includes the full xhci.h header.
>>>>>>>>>>> This series cleans up that a bit so cdns3 will only include xhci quirk bits and
>>>>>>>>>>> platform data structure.
>>>>>>>>>>>
>>>>>>>>>>> On the downside we add a couple xhci related header files to include/linux/usb/
>>>>>>>>>>> Let me know if you see any other issues I missed with this approach.
>>>>>>>>>> The problem here is that these drivers are now coupled together, and
>>>>>>>>>> that should not be taken lightly. We have a dependency hell in our
>>>>>>>>>> hands with a lot of drivers, and the culprit is always platform data.
>>>>>>>>>>
>>>>>>>>>> Build-in device properties may be messy, but I would still say they
>>>>>>>>>> are less messy than those quirk flags - you got to admit, they are a
>>>>>>>>>> mess. The benefit from build-in properties is in any case the fact
>>>>>>>>>> that they remove the need to couple these drivers together.
>>>>>>>>> Agree, quirk bits are messy. Any suggestion that would work with
>>>>>>>>> PCI xHCI devices, devicetree, and "pure" platform devices?
>>>>>>>> I think xHCI driver should always be able to rely on being able to
>>>>>>>> read this kind of information from the fwnode. If there is no actual
>>>>>>>> firmware node (DT or ACPI), or if it's missing some information, the
>>>>>>>> glue driver needs to populate software node for the xHCI.
>>>>>>>>
>>>>>>>> Right now I just want to avoid having to pass the quirks using
>>>>>>>> platform data from drivers such as drivers/usb/cdns3/host.c and
>>>>>>>> drivers/usb/dwc3/host.c to xHCI.
>>>>>>>>
>>>>>>>> One way we could do that is by defining compatibility ID for both of
>>>>>>>> them that we provide using a single device property (like I guess DT
>>>>>>>> does). Then based on that compatibility ID, xhci-plat.c can set the
>>>>>>>> actual "static" quirk flags. That we could already do easily. How
>>>>>>>> would that sound to you?
>>>>>>
>>>>>> Sounds good. 
>>>>>>
>>>>>>>
>>>>>>> This was my previous patch where I was using device tree property. Should we go ahead with this approach?
>>>>>>>
>>>>>>> https://patchwork.kernel.org/project/linux-arm-msm/cover/1636353710-25582-1-git-send-email-quic_c_sanm@quicinc.com/
>>>>>>>
>>>>>>> Any further changes to this ?
>>>>>>
>>>>>> By dropping the DT part of that series we get a similar built-in device property
>>>>>> solution as Heikki initially suggested.
>>>>>>
>>>>>> How about adding the compatibility ID device property that was just suggested?
>>>>>> Then matching the Id in xhci-plat.c against a static table containing Ids and
>>>>>> xhci_plat_priv structures, with the needed quirks for dwc3.
>>>>>
>>>>> There was a comment from Pavan. Is it still possible to get this
>>>>> detail from DT?
>>>>> I guess that would still be ideal, right?
>>>>>
>>>> I was suggesting if we can have device tree param like the patch sandeep
>>>> pointed out.
>>>>
>>>> How would adding a compatible index to usb_xhci_of_match[] would work
>>>> actually? I ask this because, dwc3/host.c creates platform device and
>>>> it is not associated with any of_node, so of_driver_match_device() called
>>>> from platform bus match method does not work. one way to achieve this would
>>>> be by matching against sysdev. Something like below. Is it acceptible?
>>>>
>>>> diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
>>>> index 649ffd8..bd5d055 100644
>>>> --- a/drivers/usb/host/xhci-plat.c
>>>> +++ b/drivers/usb/host/xhci-plat.c
>>>> @@ -126,6 +126,10 @@ static const struct xhci_plat_priv xhci_plat_brcm = {
>>>>  	.quirks = XHCI_RESET_ON_RESUME,
>>>>  };
>>>>  
>>>> +static const struct xhci_plat_priv xhci_plat_dwc3 = {
>>>> +	.quirks = XHCI_SKIP_PHY_INIT,
>>>> +};
>>>> +
>>>>  static const struct of_device_id usb_xhci_of_match[] = {
>>>>  	{
>>>>  		.compatible = "generic-xhci",
>>>> @@ -167,6 +171,9 @@ static const struct of_device_id usb_xhci_of_match[] = {
>>>>  	}, {
>>>>  		.compatible = "brcm,bcm7445-xhci",
>>>>  		.data = &xhci_plat_brcm,
>>>> +	}, {
>>>> +		.compatible = "snps,dwc3",
>>>> +		.data = &xhci_plat_dwc3,
>>>>  	},
>>
>> Isn't there a risk that xhci-plat now binds to the parent dwc3 device?
>> competing with the similar of_match_table entry created in drivers/usb/dwc3/core.c
> 
> Sill of me. Yes, it does not work. Thanks for pointing it out.
> 
>>
>>>>  	{},
>>>>  };
>>>> @@ -274,6 +281,15 @@ static int xhci_plat_probe(struct platform_device *pdev)
>>>>  	else
>>>>  		priv_match = dev_get_platdata(&pdev->dev);
>>>>  
>>>> +	/* allow private data mapping with the sysdev compatible */
>>>> +	if (!priv_match) {
>>>> +		struct of_device_id *match;
>>>> +
>>>> +		match = of_match_device(usb_xhci_of_match, sysdev);
>>>> +		if (match)
>>>> +			priv_match = match->data;
>>>> +	}
>>>> +
>>>>  	if (priv_match) {
>>>>  		priv = hcd_to_xhci_priv(hcd);
>>>>  		/* Just copy data for now */
>>>>
>>>>> I have another question. Can't we now just assume that if the sysdev
>>>>> is the parent (or grandparent), then the phy initialization should
>>>>> always be skipped? In that case we could just do something like this:
>>>>>
>>>>> diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
>>>>> index 649ffd861b44e..1018b33488046 100644
>>>>> --- a/drivers/usb/host/xhci-plat.c
>>>>> +++ b/drivers/usb/host/xhci-plat.c
>>>>> @@ -212,8 +212,12 @@ static int xhci_plat_probe(struct platform_device *pdev)
>>>>>  #endif
>>>>>         }
>>>>>  
>>>>> -       if (!sysdev)
>>>>> +       if (sysdev) {
>>>>> +               if (sysdev != &pdev->dev)
>>>>> +                       hcd->skip_phy_initialization = 1;
>>>>> +       } else {
>>>>>                 sysdev = &pdev->dev;
>>>>> +       }
>>>>>  
>>>>>         if (WARN_ON(!sysdev->dma_mask))
>>>>>                 /* Platform did not initialize dma_mask */
>>>>>
>>>>>
>>>>> I did not go through all the drivers that carefully, so I may have
>>>>> missed something, but it looks like the only drivers that can have the
>>>>> sysdev as the parent or grandparent are cdns3 and dwc3.
>>>>>
>>>> I cross checked and these are two drivers that are creating xhci-plat device.
>>>> So this patch would definitely work. However I am not sure in future if any
>>>> device created via device tree would want to use this feature. For now,
>>>> it looks good. It Mathias, Do you see any problem with this approach?
>>>>
>>
>> Would work for now but seems like a risk to assume this would hold for all future
>> xhci platform devices. 
>>
> Agree that it may break in future for other drivers.
> 
>>>
>>> Can you please provide your suggestions on this? We have discussed about
>>> 3 approaches here other than the whole platform data refactoring done.
>>>
>>> (1) Introduce a new dT property and expect dwc3/host.c to set this property
>>> to skip the phy initialization.
>>
>> Adding one more device property to swnode in dwc3/host.c starts
>> to look like the best option for now even if it didn't appeal initially.
>>
>> The place creating the xhci platform device should have best info on what properties
>> are needed for the platform device.
>>
>> So this would be just like Heikki's first suggestion, or Sandeep's patches 2/3 and 3/3 in:
>> https://patchwork.kernel.org/project/linux-arm-msm/cover/1636353710-25582-1-git-send-email-quic_c_sanm@quicinc.com/
>> but without the devicetree binding documentation part.
>>
> Why do you say devicetree binding doc is not needed in this case? Possible
> that xhci-plat's device can be coming from dT and this param is passed to
> skip initialization of PHY.

Adding it is fine by me. It was rejected earlier by Rob Herring

But we can live without it.
In dwc3 and cdns3 "pure" platform case we add the device property when
creating the device.

In dT case we should have a compatible entry, and we can add a matching
entry in usb_xhci_of_match[] which sets the needed quirk.

Thanks
-Mathias

Re: [PATCH v3 3/3] usb: dwc: host: add xhci_plat_priv quirk XHCI_SKIP_PHY_INIT

[Pavan Kondeti]

Hi Mathias,

On Wed, Apr 06, 2022 at 03:18:17PM +0300, Mathias Nyman wrote:
> On 6.4.2022 14.01, Pavan Kondeti wrote:
> > Hi Mathias,
> > 
> > On Wed, Apr 06, 2022 at 01:52:56PM +0300, Mathias Nyman wrote:
> >> Hi
> >>
> >> Sorry about the delayed response.
> >>
> >>
> >> On 6.4.2022 9.25, Pavan Kondeti wrote:
> >>> Hi Heikki/Mathias,
> >>>
> >>> On Mon, Apr 04, 2022 at 01:55:16PM +0530, Pavan Kondeti wrote:
> >>>> Hi Heikki,
> >>>>
> >>>> On Thu, Mar 31, 2022 at 02:16:53PM +0300, Heikki Krogerus wrote:
> >>>>> On Wed, Mar 30, 2022 at 08:47:34PM +0300, Mathias Nyman wrote:
> >>>>>> On 29.3.2022 12.18, Sandeep Maheswaram (Temp) wrote:
> >>>>>>> Hi Mathias,Heikki
> >>>>>>>
> >>>>>>> On 3/25/2022 9:08 PM, Heikki Krogerus wrote:
> >>>>>>>> On Fri, Mar 25, 2022 at 04:33:27PM +0200, Mathias Nyman wrote:
> >>>>>>>>> On 25.3.2022 13.27, Heikki Krogerus wrote:
> >>>>>>>>>> On Fri, Mar 25, 2022 at 12:36:22AM +0200, Mathias Nyman wrote:
> >>>>>>>>>>> On 24.3.2022 14.27, Heikki Krogerus wrote:
> >>>>>>>>>>>> On Thu, Mar 24, 2022 at 12:07:11PM +0530, Sandeep Maheswaram wrote:
> >>>>>>>>>>>>> Currently the phy init is done from dwc3 and also xhci which makes the
> >>>>>>>>>>>>> runtime_usage value 2 for the phy which causes issue during runtime
> >>>>>>>>>>>>> suspend. When we run the below command the runtime_status still shows
> >>>>>>>>>>>>> active.
> >>>>>>>>>>>>> echo auto > /sys/bus/platform/devices/88e3000.phy/power/control
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> dwc3 manages PHY by own DRD driver, so skip the management by
> >>>>>>>>>>>>> HCD core by setting this quirk.
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> Signed-off-by: Sandeep Maheswaram <quic_c_sanm@quicinc.com>
> >>>>>>>>>>>>> ---
> >>>>>>>>>>>>>   drivers/usb/dwc3/host.c | 13 +++++++++++++
> >>>>>>>>>>>>>   1 file changed, 13 insertions(+)
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> diff --git a/drivers/usb/dwc3/host.c b/drivers/usb/dwc3/host.c
> >>>>>>>>>>>>> index eda8719..d4fcf06 100644
> >>>>>>>>>>>>> --- a/drivers/usb/dwc3/host.c
> >>>>>>>>>>>>> +++ b/drivers/usb/dwc3/host.c
> >>>>>>>>>>>>> @@ -13,6 +13,12 @@
> >>>>>>>>>>>>>   #include <linux/platform_device.h>
> >>>>>>>>>>>>>     #include "core.h"
> >>>>>>>>>>>>> +#include <linux/usb/xhci-plat.h>
> >>>>>>>>>>>>> +#include <linux/usb/xhci-quirks.h>
> >>>>>>>>>>>>> +
> >>>>>>>>>>>>> +static const struct xhci_plat_priv xhci_plat_dwc3_xhci = {
> >>>>>>>>>>>>> +    .quirks = XHCI_SKIP_PHY_INIT,
> >>>>>>>>>>>>> +};
> >>>>>>>>>>>>>     static void dwc3_host_fill_xhci_irq_res(struct dwc3 *dwc,
> >>>>>>>>>>>>>                       int irq, char *name)
> >>>>>>>>>>>>> @@ -122,6 +128,13 @@ int dwc3_host_init(struct dwc3 *dwc)
> >>>>>>>>>>>>>           }
> >>>>>>>>>>>>>       }
> >>>>>>>>>>>>>   +    ret = platform_device_add_data(xhci, &xhci_plat_dwc3_xhci,
> >>>>>>>>>>>>> +            sizeof(xhci_plat_dwc3_xhci));
> >>>>>>>>>>>>> +    if (ret) {
> >>>>>>>>>>>>> +        dev_err(dwc->dev, "failed to add data to xHCI\n");
> >>>>>>>>>>>>> +        goto err;
> >>>>>>>>>>>>> +    }
> >>>>>>>>>>>>> +
> >>>>>>>>>>>>>       ret = platform_device_add(xhci);
> >>>>>>>>>>>>>       if (ret) {
> >>>>>>>>>>>>>           dev_err(dwc->dev, "failed to register xHCI device\n");
> >>>>>>>>>>>> I think you should just use device property:
> >>>>>>>>>>>>
> >>>>>>>>>>> This was suggested in an earlier series, but was rejected as it also added
> >>>>>>>>>>> the property as a device tree parameter.
> >>>>>>>>>>>
> >>>>>>>>>>> I think adding more device properties can be messy in the long run, especially if we
> >>>>>>>>>>> need to add them for many of the existing xhci quirks.
> >>>>>>>>>>> We also end up with a mix where some device properties are listed as device tree
> >>>>>>>>>>> parameters, and some not.
> >>>>>>>>>>>
> >>>>>>>>>>> Defining xhci quirks and platform data structure in headers shared with dwc3 and cdns3
> >>>>>>>>>>> allow those drivers to easily set any existing xhci quirk, or other possible optional
> >>>>>>>>>>> callbacks.
> >>>>>>>>>>>
> >>>>>>>>>>> cdns3 driver is already doing this, but it includes the full xhci.h header.
> >>>>>>>>>>> This series cleans up that a bit so cdns3 will only include xhci quirk bits and
> >>>>>>>>>>> platform data structure.
> >>>>>>>>>>>
> >>>>>>>>>>> On the downside we add a couple xhci related header files to include/linux/usb/
> >>>>>>>>>>> Let me know if you see any other issues I missed with this approach.
> >>>>>>>>>> The problem here is that these drivers are now coupled together, and
> >>>>>>>>>> that should not be taken lightly. We have a dependency hell in our
> >>>>>>>>>> hands with a lot of drivers, and the culprit is always platform data.
> >>>>>>>>>>
> >>>>>>>>>> Build-in device properties may be messy, but I would still say they
> >>>>>>>>>> are less messy than those quirk flags - you got to admit, they are a
> >>>>>>>>>> mess. The benefit from build-in properties is in any case the fact
> >>>>>>>>>> that they remove the need to couple these drivers together.
> >>>>>>>>> Agree, quirk bits are messy. Any suggestion that would work with
> >>>>>>>>> PCI xHCI devices, devicetree, and "pure" platform devices?
> >>>>>>>> I think xHCI driver should always be able to rely on being able to
> >>>>>>>> read this kind of information from the fwnode. If there is no actual
> >>>>>>>> firmware node (DT or ACPI), or if it's missing some information, the
> >>>>>>>> glue driver needs to populate software node for the xHCI.
> >>>>>>>>
> >>>>>>>> Right now I just want to avoid having to pass the quirks using
> >>>>>>>> platform data from drivers such as drivers/usb/cdns3/host.c and
> >>>>>>>> drivers/usb/dwc3/host.c to xHCI.
> >>>>>>>>
> >>>>>>>> One way we could do that is by defining compatibility ID for both of
> >>>>>>>> them that we provide using a single device property (like I guess DT
> >>>>>>>> does). Then based on that compatibility ID, xhci-plat.c can set the
> >>>>>>>> actual "static" quirk flags. That we could already do easily. How
> >>>>>>>> would that sound to you?
> >>>>>>
> >>>>>> Sounds good. 
> >>>>>>
> >>>>>>>
> >>>>>>> This was my previous patch where I was using device tree property. Should we go ahead with this approach?
> >>>>>>>
> >>>>>>> https://patchwork.kernel.org/project/linux-arm-msm/cover/1636353710-25582-1-git-send-email-quic_c_sanm@quicinc.com/
> >>>>>>>
> >>>>>>> Any further changes to this ?
> >>>>>>
> >>>>>> By dropping the DT part of that series we get a similar built-in device property
> >>>>>> solution as Heikki initially suggested.
> >>>>>>
> >>>>>> How about adding the compatibility ID device property that was just suggested?
> >>>>>> Then matching the Id in xhci-plat.c against a static table containing Ids and
> >>>>>> xhci_plat_priv structures, with the needed quirks for dwc3.
> >>>>>
> >>>>> There was a comment from Pavan. Is it still possible to get this
> >>>>> detail from DT?
> >>>>> I guess that would still be ideal, right?
> >>>>>
> >>>> I was suggesting if we can have device tree param like the patch sandeep
> >>>> pointed out.
> >>>>
> >>>> How would adding a compatible index to usb_xhci_of_match[] would work
> >>>> actually? I ask this because, dwc3/host.c creates platform device and
> >>>> it is not associated with any of_node, so of_driver_match_device() called
> >>>> from platform bus match method does not work. one way to achieve this would
> >>>> be by matching against sysdev. Something like below. Is it acceptible?
> >>>>
> >>>> diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
> >>>> index 649ffd8..bd5d055 100644
> >>>> --- a/drivers/usb/host/xhci-plat.c
> >>>> +++ b/drivers/usb/host/xhci-plat.c
> >>>> @@ -126,6 +126,10 @@ static const struct xhci_plat_priv xhci_plat_brcm = {
> >>>>  	.quirks = XHCI_RESET_ON_RESUME,
> >>>>  };
> >>>>  
> >>>> +static const struct xhci_plat_priv xhci_plat_dwc3 = {
> >>>> +	.quirks = XHCI_SKIP_PHY_INIT,
> >>>> +};
> >>>> +
> >>>>  static const struct of_device_id usb_xhci_of_match[] = {
> >>>>  	{
> >>>>  		.compatible = "generic-xhci",
> >>>> @@ -167,6 +171,9 @@ static const struct of_device_id usb_xhci_of_match[] = {
> >>>>  	}, {
> >>>>  		.compatible = "brcm,bcm7445-xhci",
> >>>>  		.data = &xhci_plat_brcm,
> >>>> +	}, {
> >>>> +		.compatible = "snps,dwc3",
> >>>> +		.data = &xhci_plat_dwc3,
> >>>>  	},
> >>
> >> Isn't there a risk that xhci-plat now binds to the parent dwc3 device?
> >> competing with the similar of_match_table entry created in drivers/usb/dwc3/core.c
> > 
> > Sill of me. Yes, it does not work. Thanks for pointing it out.
> > 
> >>
> >>>>  	{},
> >>>>  };
> >>>> @@ -274,6 +281,15 @@ static int xhci_plat_probe(struct platform_device *pdev)
> >>>>  	else
> >>>>  		priv_match = dev_get_platdata(&pdev->dev);
> >>>>  
> >>>> +	/* allow private data mapping with the sysdev compatible */
> >>>> +	if (!priv_match) {
> >>>> +		struct of_device_id *match;
> >>>> +
> >>>> +		match = of_match_device(usb_xhci_of_match, sysdev);
> >>>> +		if (match)
> >>>> +			priv_match = match->data;
> >>>> +	}
> >>>> +
> >>>>  	if (priv_match) {
> >>>>  		priv = hcd_to_xhci_priv(hcd);
> >>>>  		/* Just copy data for now */
> >>>>
> >>>>> I have another question. Can't we now just assume that if the sysdev
> >>>>> is the parent (or grandparent), then the phy initialization should
> >>>>> always be skipped? In that case we could just do something like this:
> >>>>>
> >>>>> diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
> >>>>> index 649ffd861b44e..1018b33488046 100644
> >>>>> --- a/drivers/usb/host/xhci-plat.c
> >>>>> +++ b/drivers/usb/host/xhci-plat.c
> >>>>> @@ -212,8 +212,12 @@ static int xhci_plat_probe(struct platform_device *pdev)
> >>>>>  #endif
> >>>>>         }
> >>>>>  
> >>>>> -       if (!sysdev)
> >>>>> +       if (sysdev) {
> >>>>> +               if (sysdev != &pdev->dev)
> >>>>> +                       hcd->skip_phy_initialization = 1;
> >>>>> +       } else {
> >>>>>                 sysdev = &pdev->dev;
> >>>>> +       }
> >>>>>  
> >>>>>         if (WARN_ON(!sysdev->dma_mask))
> >>>>>                 /* Platform did not initialize dma_mask */
> >>>>>
> >>>>>
> >>>>> I did not go through all the drivers that carefully, so I may have
> >>>>> missed something, but it looks like the only drivers that can have the
> >>>>> sysdev as the parent or grandparent are cdns3 and dwc3.
> >>>>>
> >>>> I cross checked and these are two drivers that are creating xhci-plat device.
> >>>> So this patch would definitely work. However I am not sure in future if any
> >>>> device created via device tree would want to use this feature. For now,
> >>>> it looks good. It Mathias, Do you see any problem with this approach?
> >>>>
> >>
> >> Would work for now but seems like a risk to assume this would hold for all future
> >> xhci platform devices. 
> >>
> > Agree that it may break in future for other drivers.
> > 
> >>>
> >>> Can you please provide your suggestions on this? We have discussed about
> >>> 3 approaches here other than the whole platform data refactoring done.
> >>>
> >>> (1) Introduce a new dT property and expect dwc3/host.c to set this property
> >>> to skip the phy initialization.
> >>
> >> Adding one more device property to swnode in dwc3/host.c starts
> >> to look like the best option for now even if it didn't appeal initially.
> >>
> >> The place creating the xhci platform device should have best info on what properties
> >> are needed for the platform device.
> >>
> >> So this would be just like Heikki's first suggestion, or Sandeep's patches 2/3 and 3/3 in:
> >> https://patchwork.kernel.org/project/linux-arm-msm/cover/1636353710-25582-1-git-send-email-quic_c_sanm@quicinc.com/
> >> but without the devicetree binding documentation part.
> >>
> > Why do you say devicetree binding doc is not needed in this case? Possible
> > that xhci-plat's device can be coming from dT and this param is passed to
> > skip initialization of PHY.
> 
> Adding it is fine by me. It was rejected earlier by Rob Herring
> 
> But we can live without it.
> In dwc3 and cdns3 "pure" platform case we add the device property when
> creating the device.
> 
> In dT case we should have a compatible entry, and we can add a matching
> entry in usb_xhci_of_match[] which sets the needed quirk.
> 
Got it. Thanks for the explanation. We can go with Sandeep's patches 2/3 and
3/3 which add dT param and can be set by the dwc3/host.c

Thanks,
Pavan