[RFC PATCH 1/4] dt-bindings: usb: Add snps,consolidate-sgl & consolidate-sgl

[RFC PATCH 1/4] dt-bindings: usb: Add snps,consolidate-sgl & consolidate-sgl

[Tejas Joglekar]

This commit adds the documentation for consolidate-sgl, and
snps,consolidate-sgl property. These when set enables the quirk for
XHCI driver for consolidation of sg list into a temporary buffer when small
buffer sizes are scattered over the sg list not making up to MPS or total
transfer size within TRB cache size with Synopsys xHC.

Signed-off-by: Tejas Joglekar <joglekar@synopsys.com>
---
 Documentation/devicetree/bindings/usb/dwc3.txt     | 3 +++
 Documentation/devicetree/bindings/usb/usb-xhci.txt | 3 +++
 2 files changed, 6 insertions(+)

diff --git a/Documentation/devicetree/bindings/usb/dwc3.txt b/Documentation/devicetree/bindings/usb/dwc3.txt
index 9946ff9ba735..292d1f7969e4 100644
--- a/Documentation/devicetree/bindings/usb/dwc3.txt
+++ b/Documentation/devicetree/bindings/usb/dwc3.txt
@@ -104,6 +104,9 @@ Optional properties:
 			this and tx-thr-num-pkt-prd to a valid, non-zero value
 			1-16 (DWC_usb31 programming guide section 1.2.3) to
 			enable periodic ESS TX threshold.
+ - snps,consolidate-sgl: enable sg list consolidation - host mode only. Set to use
+			SG buffers of at least MPS size by consolidating smaller SG
+			buffers list into a single buffer.
 
  - <DEPRECATED> tx-fifo-resize: determines if the FIFO *has* to be reallocated.
  - snps,incr-burst-type-adjustment: Value for INCR burst type of GSBUSCFG0
diff --git a/Documentation/devicetree/bindings/usb/usb-xhci.txt b/Documentation/devicetree/bindings/usb/usb-xhci.txt
index 3f378951d624..a90d853557ee 100644
--- a/Documentation/devicetree/bindings/usb/usb-xhci.txt
+++ b/Documentation/devicetree/bindings/usb/usb-xhci.txt
@@ -43,6 +43,9 @@ Optional properties:
   - quirk-broken-port-ped: set if the controller has broken port disable mechanism
   - imod-interval-ns: default interrupt moderation interval is 5000ns
   - phys : see usb-hcd.yaml in the current directory
+  - consolidate-sgl: indicate if you need to consolidate sg list into a
+    temporary buffer when small SG buffer sizes does not make upto MPS
+    size or total transfer size across the TRB cache size.
 
 additionally the properties from usb-hcd.yaml (in the current directory) are
 supported.
-- 
2.11.0

[RFC PATCH 2/4] usb: xhci: Set quirk for XHCI_CONSOLIDATE_SG_LIST

[Tejas Joglekar]

This commit enables the quirk when the consolidate_trbs property is set
for the Synopsys xHC. This patch fixes the SNPS xHC hang issue
when the data is scattered across small buffers which does not make
atleast MPS size for given TRB cache size of SNPS xHC.

Signed-off-by: Tejas Joglekar <joglekar@synopsys.com>
---
 drivers/usb/host/xhci-pci.c  | 3 +++
 drivers/usb/host/xhci-plat.c | 3 +++
 drivers/usb/host/xhci.h      | 1 +
 3 files changed, 7 insertions(+)

diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
index 766b74723e64..cdda8e2de1c2 100644
--- a/drivers/usb/host/xhci-pci.c
+++ b/drivers/usb/host/xhci-pci.c
@@ -268,6 +268,9 @@ static void xhci_pci_quirks(struct device *dev, struct xhci_hcd *xhci)
 	     pdev->device == 0x9026)
 		xhci->quirks |= XHCI_RESET_PLL_ON_DISCONNECT;
 
+	if (pdev->vendor == PCI_VENDOR_ID_SYNOPSYS)
+		xhci->quirks |= XHCI_CONSOLIDATE_SG_LIST;
+
 	if (xhci->quirks & XHCI_RESET_ON_RESUME)
 		xhci_dbg_trace(xhci, trace_xhci_dbg_quirks,
 				"QUIRK: Resetting on resume");
diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
index 315b4552693c..8333c78dcf03 100644
--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -289,6 +289,9 @@ static int xhci_plat_probe(struct platform_device *pdev)
 		if (device_property_read_bool(tmpdev, "quirk-broken-port-ped"))
 			xhci->quirks |= XHCI_BROKEN_PORT_PED;
 
+		if (device_property_read_bool(tmpdev, "consolidate-sgl"))
+			xhci->quirks |= XHCI_CONSOLIDATE_SG_LIST;
+
 		device_property_read_u32(tmpdev, "imod-interval-ns",
 					 &xhci->imod_interval);
 	}
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 3289bb516201..a093eeaec70e 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1873,6 +1873,7 @@ struct xhci_hcd {
 #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_CONSOLIDATE_SG_LIST    BIT_ULL(36)
 
 	unsigned int		num_active_eps;
 	unsigned int		limit_active_eps;
-- 
2.11.0

[RFC PATCH 3/4] usb: dwc3: Add device property consolidate-sgl

[Tejas Joglekar]

This commit adds the consolidate-sgl property to enable quirk for the
XHCI driver with Synopsys xHC. This property is enabled as initial
property for the dwc3-haps driver.

Signed-off-by: Tejas Joglekar <joglekar@synopsys.com>
---
 drivers/usb/dwc3/core.c      | 2 ++
 drivers/usb/dwc3/core.h      | 2 ++
 drivers/usb/dwc3/dwc3-haps.c | 1 +
 drivers/usb/dwc3/host.c      | 5 ++++-
 4 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index edc17155cb2b..de1747c78cd6 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -1296,6 +1296,8 @@ static void dwc3_get_properties(struct dwc3 *dwc)
 				"snps,usb3_lpm_capable");
 	dwc->usb2_lpm_disable = device_property_read_bool(dev,
 				"snps,usb2-lpm-disable");
+	dwc->consolidate_sgl  = device_property_read_bool(dev,
+				"snps,consolidate-sgl");
 	device_property_read_u8(dev, "snps,rx-thr-num-pkt-prd",
 				&rx_thr_num_pkt_prd);
 	device_property_read_u8(dev, "snps,rx-max-burst-prd",
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 6846eb0cba13..d6e15f75809e 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -1007,6 +1007,7 @@ struct dwc3_scratchpad_array {
  *			not needed for DWC_usb31 version 1.70a-ea06 and below
  * @usb3_lpm_capable: set if hadrware supports Link Power Management
  * @usb2_lpm_disable: set to disable usb2 lpm
+ * @consolidate_sgl: set to enable the SG list consolidation
  * @disable_scramble_quirk: set if we enable the disable scramble quirk
  * @u2exit_lfps_quirk: set if we enable u2exit lfps quirk
  * @u2ss_inp3_quirk: set if we enable P3 OK for U2/SS Inactive quirk
@@ -1206,6 +1207,7 @@ struct dwc3 {
 	unsigned		dis_start_transfer_quirk:1;
 	unsigned		usb3_lpm_capable:1;
 	unsigned		usb2_lpm_disable:1;
+	unsigned		consolidate_sgl:1;
 
 	unsigned		disable_scramble_quirk:1;
 	unsigned		u2exit_lfps_quirk:1;
diff --git a/drivers/usb/dwc3/dwc3-haps.c b/drivers/usb/dwc3/dwc3-haps.c
index 3cecbf169452..495815081576 100644
--- a/drivers/usb/dwc3/dwc3-haps.c
+++ b/drivers/usb/dwc3/dwc3-haps.c
@@ -29,6 +29,7 @@ static const struct property_entry initial_properties[] = {
 	PROPERTY_ENTRY_BOOL("snps,usb3_lpm_capable"),
 	PROPERTY_ENTRY_BOOL("snps,has-lpm-erratum"),
 	PROPERTY_ENTRY_BOOL("snps,dis_enblslpm_quirk"),
+	PROPERTY_ENTRY_BOOL("snps,consolidate-sgl"),
 	PROPERTY_ENTRY_BOOL("linux,sysdev_is_parent"),
 	{ },
 };
diff --git a/drivers/usb/dwc3/host.c b/drivers/usb/dwc3/host.c
index 86dbd012b984..2de8f3f74b93 100644
--- a/drivers/usb/dwc3/host.c
+++ b/drivers/usb/dwc3/host.c
@@ -44,7 +44,7 @@ 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;
 	struct resource		*res;
@@ -95,6 +95,9 @@ int dwc3_host_init(struct dwc3 *dwc)
 	if (dwc->usb2_lpm_disable)
 		props[prop_idx++] = PROPERTY_ENTRY_BOOL("usb2-lpm-disable");
 
+	if (dwc->consolidate_sgl)
+		props[prop_idx++] = PROPERTY_ENTRY_BOOL("consolidate-sgl");
+
 	/**
 	 * WORKAROUND: dwc3 revisions <=3.00a have a limitation
 	 * where Port Disable command doesn't work.
-- 
2.11.0

[RESENDING RFC PATCH 1/4] dt-bindings: usb: Add snps,consolidate-sgl & consolidate-sgl

[Tejas Joglekar]

This commit adds the documentation for consolidate-sgl, and
snps,consolidate-sgl property. These when set enables the quirk for
XHCI driver for consolidation of sg list into a temporary buffer when small
buffer sizes are scattered over the sg list not making up to MPS or total
transfer size within TRB cache size with Synopsys xHC.

Signed-off-by: Tejas Joglekar <joglekar@synopsys.com>
---
 Documentation/devicetree/bindings/usb/dwc3.txt     | 3 +++
 Documentation/devicetree/bindings/usb/usb-xhci.txt | 3 +++
 2 files changed, 6 insertions(+)

diff --git a/Documentation/devicetree/bindings/usb/dwc3.txt b/Documentation/devicetree/bindings/usb/dwc3.txt
index 9946ff9ba735..292d1f7969e4 100644
--- a/Documentation/devicetree/bindings/usb/dwc3.txt
+++ b/Documentation/devicetree/bindings/usb/dwc3.txt
@@ -104,6 +104,9 @@ Optional properties:
 			this and tx-thr-num-pkt-prd to a valid, non-zero value
 			1-16 (DWC_usb31 programming guide section 1.2.3) to
 			enable periodic ESS TX threshold.
+ - snps,consolidate-sgl: enable sg list consolidation - host mode only. Set to use
+			SG buffers of at least MPS size by consolidating smaller SG
+			buffers list into a single buffer.
 
  - <DEPRECATED> tx-fifo-resize: determines if the FIFO *has* to be reallocated.
  - snps,incr-burst-type-adjustment: Value for INCR burst type of GSBUSCFG0
diff --git a/Documentation/devicetree/bindings/usb/usb-xhci.txt b/Documentation/devicetree/bindings/usb/usb-xhci.txt
index 3f378951d624..a90d853557ee 100644
--- a/Documentation/devicetree/bindings/usb/usb-xhci.txt
+++ b/Documentation/devicetree/bindings/usb/usb-xhci.txt
@@ -43,6 +43,9 @@ Optional properties:
   - quirk-broken-port-ped: set if the controller has broken port disable mechanism
   - imod-interval-ns: default interrupt moderation interval is 5000ns
   - phys : see usb-hcd.yaml in the current directory
+  - consolidate-sgl: indicate if you need to consolidate sg list into a
+    temporary buffer when small SG buffer sizes does not make upto MPS
+    size or total transfer size across the TRB cache size.
 
 additionally the properties from usb-hcd.yaml (in the current directory) are
 supported.
-- 
2.11.0

[RESENDING RFC PATCH 2/4] usb: xhci: Set quirk for XHCI_CONSOLIDATE_SG_LIST

[Tejas Joglekar]

This commit enables the quirk when the consolidate_trbs property is set
for the Synopsys xHC. This patch fixes the SNPS xHC hang issue
when the data is scattered across small buffers which does not make
atleast MPS size for given TRB cache size of SNPS xHC.

Signed-off-by: Tejas Joglekar <joglekar@synopsys.com>
---
 drivers/usb/host/xhci-pci.c  | 3 +++
 drivers/usb/host/xhci-plat.c | 3 +++
 drivers/usb/host/xhci.h      | 1 +
 3 files changed, 7 insertions(+)

diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
index 766b74723e64..cdda8e2de1c2 100644
--- a/drivers/usb/host/xhci-pci.c
+++ b/drivers/usb/host/xhci-pci.c
@@ -268,6 +268,9 @@ static void xhci_pci_quirks(struct device *dev, struct xhci_hcd *xhci)
 	     pdev->device == 0x9026)
 		xhci->quirks |= XHCI_RESET_PLL_ON_DISCONNECT;
 
+	if (pdev->vendor == PCI_VENDOR_ID_SYNOPSYS)
+		xhci->quirks |= XHCI_CONSOLIDATE_SG_LIST;
+
 	if (xhci->quirks & XHCI_RESET_ON_RESUME)
 		xhci_dbg_trace(xhci, trace_xhci_dbg_quirks,
 				"QUIRK: Resetting on resume");
diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
index 315b4552693c..8333c78dcf03 100644
--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -289,6 +289,9 @@ static int xhci_plat_probe(struct platform_device *pdev)
 		if (device_property_read_bool(tmpdev, "quirk-broken-port-ped"))
 			xhci->quirks |= XHCI_BROKEN_PORT_PED;
 
+		if (device_property_read_bool(tmpdev, "consolidate-sgl"))
+			xhci->quirks |= XHCI_CONSOLIDATE_SG_LIST;
+
 		device_property_read_u32(tmpdev, "imod-interval-ns",
 					 &xhci->imod_interval);
 	}
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 3289bb516201..a093eeaec70e 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1873,6 +1873,7 @@ struct xhci_hcd {
 #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_CONSOLIDATE_SG_LIST    BIT_ULL(36)
 
 	unsigned int		num_active_eps;
 	unsigned int		limit_active_eps;
-- 
2.11.0

[RESENDING RFC PATCH 3/4] usb: dwc3: Add device property consolidate-sgl

[Tejas Joglekar]

This commit adds the consolidate-sgl property to enable quirk for the
XHCI driver with Synopsys xHC. This property is enabled as initial
property for the dwc3-haps driver.

Signed-off-by: Tejas Joglekar <joglekar@synopsys.com>
---
 drivers/usb/dwc3/core.c      | 2 ++
 drivers/usb/dwc3/core.h      | 2 ++
 drivers/usb/dwc3/dwc3-haps.c | 1 +
 drivers/usb/dwc3/host.c      | 5 ++++-
 4 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index edc17155cb2b..de1747c78cd6 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -1296,6 +1296,8 @@ static void dwc3_get_properties(struct dwc3 *dwc)
 				"snps,usb3_lpm_capable");
 	dwc->usb2_lpm_disable = device_property_read_bool(dev,
 				"snps,usb2-lpm-disable");
+	dwc->consolidate_sgl  = device_property_read_bool(dev,
+				"snps,consolidate-sgl");
 	device_property_read_u8(dev, "snps,rx-thr-num-pkt-prd",
 				&rx_thr_num_pkt_prd);
 	device_property_read_u8(dev, "snps,rx-max-burst-prd",
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 6846eb0cba13..d6e15f75809e 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -1007,6 +1007,7 @@ struct dwc3_scratchpad_array {
  *			not needed for DWC_usb31 version 1.70a-ea06 and below
  * @usb3_lpm_capable: set if hadrware supports Link Power Management
  * @usb2_lpm_disable: set to disable usb2 lpm
+ * @consolidate_sgl: set to enable the SG list consolidation
  * @disable_scramble_quirk: set if we enable the disable scramble quirk
  * @u2exit_lfps_quirk: set if we enable u2exit lfps quirk
  * @u2ss_inp3_quirk: set if we enable P3 OK for U2/SS Inactive quirk
@@ -1206,6 +1207,7 @@ struct dwc3 {
 	unsigned		dis_start_transfer_quirk:1;
 	unsigned		usb3_lpm_capable:1;
 	unsigned		usb2_lpm_disable:1;
+	unsigned		consolidate_sgl:1;
 
 	unsigned		disable_scramble_quirk:1;
 	unsigned		u2exit_lfps_quirk:1;
diff --git a/drivers/usb/dwc3/dwc3-haps.c b/drivers/usb/dwc3/dwc3-haps.c
index 3cecbf169452..495815081576 100644
--- a/drivers/usb/dwc3/dwc3-haps.c
+++ b/drivers/usb/dwc3/dwc3-haps.c
@@ -29,6 +29,7 @@ static const struct property_entry initial_properties[] = {
 	PROPERTY_ENTRY_BOOL("snps,usb3_lpm_capable"),
 	PROPERTY_ENTRY_BOOL("snps,has-lpm-erratum"),
 	PROPERTY_ENTRY_BOOL("snps,dis_enblslpm_quirk"),
+	PROPERTY_ENTRY_BOOL("snps,consolidate-sgl"),
 	PROPERTY_ENTRY_BOOL("linux,sysdev_is_parent"),
 	{ },
 };
diff --git a/drivers/usb/dwc3/host.c b/drivers/usb/dwc3/host.c
index 86dbd012b984..2de8f3f74b93 100644
--- a/drivers/usb/dwc3/host.c
+++ b/drivers/usb/dwc3/host.c
@@ -44,7 +44,7 @@ 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;
 	struct resource		*res;
@@ -95,6 +95,9 @@ int dwc3_host_init(struct dwc3 *dwc)
 	if (dwc->usb2_lpm_disable)
 		props[prop_idx++] = PROPERTY_ENTRY_BOOL("usb2-lpm-disable");
 
+	if (dwc->consolidate_sgl)
+		props[prop_idx++] = PROPERTY_ENTRY_BOOL("consolidate-sgl");
+
 	/**
 	 * WORKAROUND: dwc3 revisions <=3.00a have a limitation
 	 * where Port Disable command doesn't work.
-- 
2.11.0

Re: [RESENDING RFC PATCH 1/4] dt-bindings: usb: Add snps,consolidate-sgl & consolidate-sgl

[Greg KH]

On Fri, Mar 27, 2020 at 03:11:56PM +0530, Tejas Joglekar wrote:
> This commit adds the documentation for consolidate-sgl, and
> snps,consolidate-sgl property. These when set enables the quirk for
> XHCI driver for consolidation of sg list into a temporary buffer when small
> buffer sizes are scattered over the sg list not making up to MPS or total
> transfer size within TRB cache size with Synopsys xHC.
> 
> Signed-off-by: Tejas Joglekar <joglekar@synopsys.com>
> ---
>  Documentation/devicetree/bindings/usb/dwc3.txt     | 3 +++
>  Documentation/devicetree/bindings/usb/usb-xhci.txt | 3 +++
>  2 files changed, 6 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/usb/dwc3.txt b/Documentation/devicetree/bindings/usb/dwc3.txt
> index 9946ff9ba735..292d1f7969e4 100644
> --- a/Documentation/devicetree/bindings/usb/dwc3.txt
> +++ b/Documentation/devicetree/bindings/usb/dwc3.txt
> @@ -104,6 +104,9 @@ Optional properties:
>  			this and tx-thr-num-pkt-prd to a valid, non-zero value
>  			1-16 (DWC_usb31 programming guide section 1.2.3) to
>  			enable periodic ESS TX threshold.
> + - snps,consolidate-sgl: enable sg list consolidation - host mode only. Set to use
> +			SG buffers of at least MPS size by consolidating smaller SG
> +			buffers list into a single buffer.
>  
>   - <DEPRECATED> tx-fifo-resize: determines if the FIFO *has* to be reallocated.
>   - snps,incr-burst-type-adjustment: Value for INCR burst type of GSBUSCFG0
> diff --git a/Documentation/devicetree/bindings/usb/usb-xhci.txt b/Documentation/devicetree/bindings/usb/usb-xhci.txt
> index 3f378951d624..a90d853557ee 100644
> --- a/Documentation/devicetree/bindings/usb/usb-xhci.txt
> +++ b/Documentation/devicetree/bindings/usb/usb-xhci.txt
> @@ -43,6 +43,9 @@ Optional properties:
>    - quirk-broken-port-ped: set if the controller has broken port disable mechanism
>    - imod-interval-ns: default interrupt moderation interval is 5000ns
>    - phys : see usb-hcd.yaml in the current directory
> +  - consolidate-sgl: indicate if you need to consolidate sg list into a
> +    temporary buffer when small SG buffer sizes does not make upto MPS
> +    size or total transfer size across the TRB cache size.

Shouldn't this refer to the fact that the hardware is broken?  Otherwise
why would anyone know if they should, or should not, enable this option?

thanks,

greg k-h

Re: [RESENDING RFC PATCH 1/4] dt-bindings: usb: Add snps,consolidate-sgl & consolidate-sgl

[Tejas Joglekar]

Hi,
On 3/27/2020 3:24 PM, Greg KH wrote:
> On Fri, Mar 27, 2020 at 03:11:56PM +0530, Tejas Joglekar wrote:
>> This commit adds the documentation for consolidate-sgl, and
>> snps,consolidate-sgl property. These when set enables the quirk for
>> XHCI driver for consolidation of sg list into a temporary buffer when small
>> buffer sizes are scattered over the sg list not making up to MPS or total
>> transfer size within TRB cache size with Synopsys xHC.
>>
>> Signed-off-by: Tejas Joglekar <joglekar@synopsys.com>
>> ---
>>  Documentation/devicetree/bindings/usb/dwc3.txt     | 3 +++
>>  Documentation/devicetree/bindings/usb/usb-xhci.txt | 3 +++
>>  2 files changed, 6 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/usb/dwc3.txt b/Documentation/devicetree/bindings/usb/dwc3.txt
>> index 9946ff9ba735..292d1f7969e4 100644
>> --- a/Documentation/devicetree/bindings/usb/dwc3.txt
>> +++ b/Documentation/devicetree/bindings/usb/dwc3.txt
>> @@ -104,6 +104,9 @@ Optional properties:
>>  			this and tx-thr-num-pkt-prd to a valid, non-zero value
>>  			1-16 (DWC_usb31 programming guide section 1.2.3) to
>>  			enable periodic ESS TX threshold.
>> + - snps,consolidate-sgl: enable sg list consolidation - host mode only. Set to use
>> +			SG buffers of at least MPS size by consolidating smaller SG
>> +			buffers list into a single buffer.
>>  
>>   - <DEPRECATED> tx-fifo-resize: determines if the FIFO *has* to be reallocated.
>>   - snps,incr-burst-type-adjustment: Value for INCR burst type of GSBUSCFG0
>> diff --git a/Documentation/devicetree/bindings/usb/usb-xhci.txt b/Documentation/devicetree/bindings/usb/usb-xhci.txt
>> index 3f378951d624..a90d853557ee 100644
>> --- a/Documentation/devicetree/bindings/usb/usb-xhci.txt
>> +++ b/Documentation/devicetree/bindings/usb/usb-xhci.txt
>> @@ -43,6 +43,9 @@ Optional properties:
>>    - quirk-broken-port-ped: set if the controller has broken port disable mechanism
>>    - imod-interval-ns: default interrupt moderation interval is 5000ns
>>    - phys : see usb-hcd.yaml in the current directory
>> +  - consolidate-sgl: indicate if you need to consolidate sg list into a
>> +    temporary buffer when small SG buffer sizes does not make upto MPS
>> +    size or total transfer size across the TRB cache size.
> 
> Shouldn't this refer to the fact that the hardware is broken?  Otherwise
> why would anyone know if they should, or should not, enable this option?
>
We have not seen issue with Linux environment for now. But with other OS with
SG list with very small buffer sizes the xHC controller hang was seen. So 
currently introducing the binding as optional one. One could enable this 
option when xHC halt happens due to small SG list sizes.  
 
> thanks,
> 
> greg k-h
> 

Thanks & Regards,
 Tejas Joglekar

Re: [RESENDING RFC PATCH 1/4] dt-bindings: usb: Add snps,consolidate-sgl & consolidate-sgl

[Greg KH]

On Fri, Mar 27, 2020 at 10:11:59AM +0000, Tejas Joglekar wrote:
> Hi,
> On 3/27/2020 3:24 PM, Greg KH wrote:
> > On Fri, Mar 27, 2020 at 03:11:56PM +0530, Tejas Joglekar wrote:
> >> This commit adds the documentation for consolidate-sgl, and
> >> snps,consolidate-sgl property. These when set enables the quirk for
> >> XHCI driver for consolidation of sg list into a temporary buffer when small
> >> buffer sizes are scattered over the sg list not making up to MPS or total
> >> transfer size within TRB cache size with Synopsys xHC.
> >>
> >> Signed-off-by: Tejas Joglekar <joglekar@synopsys.com>
> >> ---
> >>  Documentation/devicetree/bindings/usb/dwc3.txt     | 3 +++
> >>  Documentation/devicetree/bindings/usb/usb-xhci.txt | 3 +++
> >>  2 files changed, 6 insertions(+)
> >>
> >> diff --git a/Documentation/devicetree/bindings/usb/dwc3.txt b/Documentation/devicetree/bindings/usb/dwc3.txt
> >> index 9946ff9ba735..292d1f7969e4 100644
> >> --- a/Documentation/devicetree/bindings/usb/dwc3.txt
> >> +++ b/Documentation/devicetree/bindings/usb/dwc3.txt
> >> @@ -104,6 +104,9 @@ Optional properties:
> >>  			this and tx-thr-num-pkt-prd to a valid, non-zero value
> >>  			1-16 (DWC_usb31 programming guide section 1.2.3) to
> >>  			enable periodic ESS TX threshold.
> >> + - snps,consolidate-sgl: enable sg list consolidation - host mode only. Set to use
> >> +			SG buffers of at least MPS size by consolidating smaller SG
> >> +			buffers list into a single buffer.
> >>  
> >>   - <DEPRECATED> tx-fifo-resize: determines if the FIFO *has* to be reallocated.
> >>   - snps,incr-burst-type-adjustment: Value for INCR burst type of GSBUSCFG0
> >> diff --git a/Documentation/devicetree/bindings/usb/usb-xhci.txt b/Documentation/devicetree/bindings/usb/usb-xhci.txt
> >> index 3f378951d624..a90d853557ee 100644
> >> --- a/Documentation/devicetree/bindings/usb/usb-xhci.txt
> >> +++ b/Documentation/devicetree/bindings/usb/usb-xhci.txt
> >> @@ -43,6 +43,9 @@ Optional properties:
> >>    - quirk-broken-port-ped: set if the controller has broken port disable mechanism
> >>    - imod-interval-ns: default interrupt moderation interval is 5000ns
> >>    - phys : see usb-hcd.yaml in the current directory
> >> +  - consolidate-sgl: indicate if you need to consolidate sg list into a
> >> +    temporary buffer when small SG buffer sizes does not make upto MPS
> >> +    size or total transfer size across the TRB cache size.
> > 
> > Shouldn't this refer to the fact that the hardware is broken?  Otherwise
> > why would anyone know if they should, or should not, enable this option?
> >
> We have not seen issue with Linux environment for now. But with other OS with
> SG list with very small buffer sizes the xHC controller hang was seen. So 
> currently introducing the binding as optional one. One could enable this 
> option when xHC halt happens due to small SG list sizes.  

What I mean is this should be something like,
"quirk-broken-sg-list-handler" or something like that.  Otherwise how
does anyone know if this really is needed or not.  Reading this would
seem like everyone would like to do this, as consolidating links
sounds like a good optimization, when instead this really cause more
memory allocations, making this possibly worse performance.

thanks,

greg k-h

Re: [RESENDING RFC PATCH 1/4] dt-bindings: usb: Add snps,consolidate-sgl & consolidate-sgl

[Tejas Joglekar]

On 3/27/2020 3:54 PM, Greg KH wrote:
> On Fri, Mar 27, 2020 at 10:11:59AM +0000, Tejas Joglekar wrote:
>> Hi,
>> On 3/27/2020 3:24 PM, Greg KH wrote:
>>> On Fri, Mar 27, 2020 at 03:11:56PM +0530, Tejas Joglekar wrote:
>>>> This commit adds the documentation for consolidate-sgl, and
>>>> snps,consolidate-sgl property. These when set enables the quirk for
>>>> XHCI driver for consolidation of sg list into a temporary buffer when small
>>>> buffer sizes are scattered over the sg list not making up to MPS or total
>>>> transfer size within TRB cache size with Synopsys xHC.
>>>>
>>>> Signed-off-by: Tejas Joglekar <joglekar@synopsys.com>
>>>> ---
>>>>  Documentation/devicetree/bindings/usb/dwc3.txt     | 3 +++
>>>>  Documentation/devicetree/bindings/usb/usb-xhci.txt | 3 +++
>>>>  2 files changed, 6 insertions(+)
>>>>
>>>> diff --git a/Documentation/devicetree/bindings/usb/dwc3.txt b/Documentation/devicetree/bindings/usb/dwc3.txt
>>>> index 9946ff9ba735..292d1f7969e4 100644
>>>> --- a/Documentation/devicetree/bindings/usb/dwc3.txt
>>>> +++ b/Documentation/devicetree/bindings/usb/dwc3.txt
>>>> @@ -104,6 +104,9 @@ Optional properties:
>>>>  			this and tx-thr-num-pkt-prd to a valid, non-zero value
>>>>  			1-16 (DWC_usb31 programming guide section 1.2.3) to
>>>>  			enable periodic ESS TX threshold.
>>>> + - snps,consolidate-sgl: enable sg list consolidation - host mode only. Set to use
>>>> +			SG buffers of at least MPS size by consolidating smaller SG
>>>> +			buffers list into a single buffer.
>>>>  
>>>>   - <DEPRECATED> tx-fifo-resize: determines if the FIFO *has* to be reallocated.
>>>>   - snps,incr-burst-type-adjustment: Value for INCR burst type of GSBUSCFG0
>>>> diff --git a/Documentation/devicetree/bindings/usb/usb-xhci.txt b/Documentation/devicetree/bindings/usb/usb-xhci.txt
>>>> index 3f378951d624..a90d853557ee 100644
>>>> --- a/Documentation/devicetree/bindings/usb/usb-xhci.txt
>>>> +++ b/Documentation/devicetree/bindings/usb/usb-xhci.txt
>>>> @@ -43,6 +43,9 @@ Optional properties:
>>>>    - quirk-broken-port-ped: set if the controller has broken port disable mechanism
>>>>    - imod-interval-ns: default interrupt moderation interval is 5000ns
>>>>    - phys : see usb-hcd.yaml in the current directory
>>>> +  - consolidate-sgl: indicate if you need to consolidate sg list into a
>>>> +    temporary buffer when small SG buffer sizes does not make upto MPS
>>>> +    size or total transfer size across the TRB cache size.
>>>
>>> Shouldn't this refer to the fact that the hardware is broken?  Otherwise
>>> why would anyone know if they should, or should not, enable this option?
>>>
>> We have not seen issue with Linux environment for now. But with other OS with
>> SG list with very small buffer sizes the xHC controller hang was seen. So 
>> currently introducing the binding as optional one. One could enable this 
>> option when xHC halt happens due to small SG list sizes.  
> 
> What I mean is this should be something like,
> "quirk-broken-sg-list-handler" or something like that.  Otherwise how
> does anyone know if this really is needed or not.  Reading this would
> seem like everyone would like to do this, as consolidating links
> sounds like a good optimization, when instead this really cause more
> memory allocations, making this possibly worse performance.
> 
Sure, understood. I will rename this entry.
> thanks,
> 
> greg k-h
> 

Thanks & Regards,
 Tejas Joglekar

Re: [RESENDING RFC PATCH 1/4] dt-bindings: usb: Add snps,consolidate-sgl & consolidate-sgl

[Rob Herring]

On Fri, Mar 27, 2020 at 03:11:56PM +0530, Tejas Joglekar wrote:
> This commit adds the documentation for consolidate-sgl, and
> snps,consolidate-sgl property. These when set enables the quirk for
> XHCI driver for consolidation of sg list into a temporary buffer when small
> buffer sizes are scattered over the sg list not making up to MPS or total
> transfer size within TRB cache size with Synopsys xHC.
> 
> Signed-off-by: Tejas Joglekar <joglekar@synopsys.com>
> ---
>  Documentation/devicetree/bindings/usb/dwc3.txt     | 3 +++
>  Documentation/devicetree/bindings/usb/usb-xhci.txt | 3 +++
>  2 files changed, 6 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/usb/dwc3.txt b/Documentation/devicetree/bindings/usb/dwc3.txt
> index 9946ff9ba735..292d1f7969e4 100644
> --- a/Documentation/devicetree/bindings/usb/dwc3.txt
> +++ b/Documentation/devicetree/bindings/usb/dwc3.txt
> @@ -104,6 +104,9 @@ Optional properties:
>  			this and tx-thr-num-pkt-prd to a valid, non-zero value
>  			1-16 (DWC_usb31 programming guide section 1.2.3) to
>  			enable periodic ESS TX threshold.
> + - snps,consolidate-sgl: enable sg list consolidation - host mode only. Set to use
> +			SG buffers of at least MPS size by consolidating smaller SG
> +			buffers list into a single buffer.

The preference is not to keep adding properties for every single quirk 
or feature. These should be implied by specific compatibles. As Synopsys 
knows what quirks/errata/features are in each version of IP, the 
compatible strings should reflect those versions. (And yes, I'm sure 
there's customer ECO fixes that aren't reflected in the version, but 
that's why we have SoC specific compatibles too.) This is the only way 
we can fix quirks in the OS without doing DT updates. For comparison, do 
you want to have to update your PC BIOS so an OS can work-around issues?

Rob

Re: [RESENDING RFC PATCH 1/4] dt-bindings: usb: Add snps,consolidate-sgl & consolidate-sgl

[Tejas Joglekar]

Hi,
On 4/5/2020 7:15 AM, Rob Herring wrote:
> On Fri, Mar 27, 2020 at 03:11:56PM +0530, Tejas Joglekar wrote:
>> This commit adds the documentation for consolidate-sgl, and
>> snps,consolidate-sgl property. These when set enables the quirk for
>> XHCI driver for consolidation of sg list into a temporary buffer when small
>> buffer sizes are scattered over the sg list not making up to MPS or total
>> transfer size within TRB cache size with Synopsys xHC.
>>
>> Signed-off-by: Tejas Joglekar <joglekar@synopsys.com>
>> ---
>>  Documentation/devicetree/bindings/usb/dwc3.txt     | 3 +++
>>  Documentation/devicetree/bindings/usb/usb-xhci.txt | 3 +++
>>  2 files changed, 6 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/usb/dwc3.txt b/Documentation/devicetree/bindings/usb/dwc3.txt
>> index 9946ff9ba735..292d1f7969e4 100644
>> --- a/Documentation/devicetree/bindings/usb/dwc3.txt
>> +++ b/Documentation/devicetree/bindings/usb/dwc3.txt
>> @@ -104,6 +104,9 @@ Optional properties:
>>  			this and tx-thr-num-pkt-prd to a valid, non-zero value
>>  			1-16 (DWC_usb31 programming guide section 1.2.3) to
>>  			enable periodic ESS TX threshold.
>> + - snps,consolidate-sgl: enable sg list consolidation - host mode only. Set to use
>> +			SG buffers of at least MPS size by consolidating smaller SG
>> +			buffers list into a single buffer.
> 
> The preference is not to keep adding properties for every single quirk 
> or feature. These should be implied by specific compatibles. As Synopsys 
> knows what quirks/errata/features are in each version of IP, the 
> compatible strings should reflect those versions. (And yes, I'm sure 
> there's customer ECO fixes that aren't reflected in the version, but 
> that's why we have SoC specific compatibles too.) This is the only way 
> we can fix quirks in the OS without doing DT updates. For comparison, do 
> you want to have to update your PC BIOS so an OS can work-around issues?
>
Yes, I understand what you want to say here. But I think this compatible string
does not work with the platform drivers with PCI based systems. So based on the vendor 
id and device id then I need to set the quirk required. 

@Felipe: What do you suggest for setting up quirk without the DT update for dwc3?
 
> Rob
> 

Thanks & Regards,
 Tejas Joglekar

Re: [RESENDING RFC PATCH 1/4] dt-bindings: usb: Add snps,consolidate-sgl & consolidate-sgl

[Felipe Balbi]

[-- Attachment #1: Type: text/plain, Size: 2694 bytes --]


Hi,

Tejas Joglekar <Tejas.Joglekar@synopsys.com> writes:
> Hi,
> On 4/5/2020 7:15 AM, Rob Herring wrote:
>> On Fri, Mar 27, 2020 at 03:11:56PM +0530, Tejas Joglekar wrote:
>>> This commit adds the documentation for consolidate-sgl, and
>>> snps,consolidate-sgl property. These when set enables the quirk for
>>> XHCI driver for consolidation of sg list into a temporary buffer when small
>>> buffer sizes are scattered over the sg list not making up to MPS or total
>>> transfer size within TRB cache size with Synopsys xHC.
>>>
>>> Signed-off-by: Tejas Joglekar <joglekar@synopsys.com>
>>> ---
>>>  Documentation/devicetree/bindings/usb/dwc3.txt     | 3 +++
>>>  Documentation/devicetree/bindings/usb/usb-xhci.txt | 3 +++
>>>  2 files changed, 6 insertions(+)
>>>
>>> diff --git a/Documentation/devicetree/bindings/usb/dwc3.txt b/Documentation/devicetree/bindings/usb/dwc3.txt
>>> index 9946ff9ba735..292d1f7969e4 100644
>>> --- a/Documentation/devicetree/bindings/usb/dwc3.txt
>>> +++ b/Documentation/devicetree/bindings/usb/dwc3.txt
>>> @@ -104,6 +104,9 @@ Optional properties:
>>>  			this and tx-thr-num-pkt-prd to a valid, non-zero value
>>>  			1-16 (DWC_usb31 programming guide section 1.2.3) to
>>>  			enable periodic ESS TX threshold.
>>> + - snps,consolidate-sgl: enable sg list consolidation - host mode only. Set to use
>>> +			SG buffers of at least MPS size by consolidating smaller SG
>>> +			buffers list into a single buffer.
>> 
>> The preference is not to keep adding properties for every single quirk 
>> or feature. These should be implied by specific compatibles. As Synopsys 
>> knows what quirks/errata/features are in each version of IP, the 
>> compatible strings should reflect those versions. (And yes, I'm sure 
>> there's customer ECO fixes that aren't reflected in the version, but 
>> that's why we have SoC specific compatibles too.) This is the only way 
>> we can fix quirks in the OS without doing DT updates. For comparison, do 
>> you want to have to update your PC BIOS so an OS can work-around issues?
>>
> Yes, I understand what you want to say here. But I think this compatible string
> does not work with the platform drivers with PCI based systems. So based on the vendor 
> id and device id then I need to set the quirk required. 
>
> @Felipe: What do you suggest for setting up quirk without the DT update for dwc3?

We have been using Synopsys controller's revision register, but that's
not visible to xhci driver and we don't have a separate compatible for
each synopsys version on the xhci driver side. One option would be to
add "snps,xhci-foo-bar" to xhci-plat and use that.

-- 
balbi

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 832 bytes --]

Re: [RESENDING RFC PATCH 1/4] dt-bindings: usb: Add snps,consolidate-sgl & consolidate-sgl

[Tejas Joglekar]

Hi,
On 4/16/2020 1:52 PM, Felipe Balbi wrote:
> 
> Hi,
> 
> Tejas Joglekar <Tejas.Joglekar@synopsys.com> writes:
>> Hi,
>> On 4/5/2020 7:15 AM, Rob Herring wrote:
>>> On Fri, Mar 27, 2020 at 03:11:56PM +0530, Tejas Joglekar wrote:
>>>> This commit adds the documentation for consolidate-sgl, and
>>>> snps,consolidate-sgl property. These when set enables the quirk for
>>>> XHCI driver for consolidation of sg list into a temporary buffer when small
>>>> buffer sizes are scattered over the sg list not making up to MPS or total
>>>> transfer size within TRB cache size with Synopsys xHC.
>>>>
>>>> Signed-off-by: Tejas Joglekar <joglekar@synopsys.com>
>>>> ---
>>>>  Documentation/devicetree/bindings/usb/dwc3.txt     | 3 +++
>>>>  Documentation/devicetree/bindings/usb/usb-xhci.txt | 3 +++
>>>>  2 files changed, 6 insertions(+)
>>>>
>>>> diff --git a/Documentation/devicetree/bindings/usb/dwc3.txt b/Documentation/devicetree/bindings/usb/dwc3.txt
>>>> index 9946ff9ba735..292d1f7969e4 100644
>>>> --- a/Documentation/devicetree/bindings/usb/dwc3.txt
>>>> +++ b/Documentation/devicetree/bindings/usb/dwc3.txt
>>>> @@ -104,6 +104,9 @@ Optional properties:
>>>>  			this and tx-thr-num-pkt-prd to a valid, non-zero value
>>>>  			1-16 (DWC_usb31 programming guide section 1.2.3) to
>>>>  			enable periodic ESS TX threshold.
>>>> + - snps,consolidate-sgl: enable sg list consolidation - host mode only. Set to use
>>>> +			SG buffers of at least MPS size by consolidating smaller SG
>>>> +			buffers list into a single buffer.
>>>
>>> The preference is not to keep adding properties for every single quirk 
>>> or feature. These should be implied by specific compatibles. As Synopsys 
>>> knows what quirks/errata/features are in each version of IP, the 
>>> compatible strings should reflect those versions. (And yes, I'm sure 
>>> there's customer ECO fixes that aren't reflected in the version, but 
>>> that's why we have SoC specific compatibles too.) This is the only way 
>>> we can fix quirks in the OS without doing DT updates. For comparison, do 
>>> you want to have to update your PC BIOS so an OS can work-around issues?
>>>
>> Yes, I understand what you want to say here. But I think this compatible string
>> does not work with the platform drivers with PCI based systems. So based on the vendor 
>> id and device id then I need to set the quirk required. 
>>
>> @Felipe: What do you suggest for setting up quirk without the DT update for dwc3?
> 
> We have been using Synopsys controller's revision register, but that's
> not visible to xhci driver and we don't have a separate compatible for
> each synopsys version on the xhci driver side. One option would be to
> add "snps,xhci-foo-bar" to xhci-plat and use that.
> 
@Felipe: Thanks for suggestion

@Mathias: Do you prefer parameter passed this way? I can send the v2 patch set,
after your input.


Thanks & Regards,
 Tejas Joglekar 

Re: [RESENDING RFC PATCH 1/4] dt-bindings: usb: Add snps,consolidate-sgl & consolidate-sgl

[Mathias Nyman]

On 16.4.2020 19.37, Tejas Joglekar wrote:
> Hi,
> On 4/16/2020 1:52 PM, Felipe Balbi wrote:
>>
>> Hi,
>>
>> Tejas Joglekar <Tejas.Joglekar@synopsys.com> writes:
>>> Hi,
>>> On 4/5/2020 7:15 AM, Rob Herring wrote:
>>>> On Fri, Mar 27, 2020 at 03:11:56PM +0530, Tejas Joglekar wrote:
>>>>> This commit adds the documentation for consolidate-sgl, and
>>>>> snps,consolidate-sgl property. These when set enables the quirk for
>>>>> XHCI driver for consolidation of sg list into a temporary buffer when small
>>>>> buffer sizes are scattered over the sg list not making up to MPS or total
>>>>> transfer size within TRB cache size with Synopsys xHC.
>>>>>
>>>>> Signed-off-by: Tejas Joglekar <joglekar@synopsys.com>
>>>>> ---
>>>>>  Documentation/devicetree/bindings/usb/dwc3.txt     | 3 +++
>>>>>  Documentation/devicetree/bindings/usb/usb-xhci.txt | 3 +++
>>>>>  2 files changed, 6 insertions(+)
>>>>>
>>>>> diff --git a/Documentation/devicetree/bindings/usb/dwc3.txt b/Documentation/devicetree/bindings/usb/dwc3.txt
>>>>> index 9946ff9ba735..292d1f7969e4 100644
>>>>> --- a/Documentation/devicetree/bindings/usb/dwc3.txt
>>>>> +++ b/Documentation/devicetree/bindings/usb/dwc3.txt
>>>>> @@ -104,6 +104,9 @@ Optional properties:
>>>>>  			this and tx-thr-num-pkt-prd to a valid, non-zero value
>>>>>  			1-16 (DWC_usb31 programming guide section 1.2.3) to
>>>>>  			enable periodic ESS TX threshold.
>>>>> + - snps,consolidate-sgl: enable sg list consolidation - host mode only. Set to use
>>>>> +			SG buffers of at least MPS size by consolidating smaller SG
>>>>> +			buffers list into a single buffer.
>>>>
>>>> The preference is not to keep adding properties for every single quirk 
>>>> or feature. These should be implied by specific compatibles. As Synopsys 
>>>> knows what quirks/errata/features are in each version of IP, the 
>>>> compatible strings should reflect those versions. (And yes, I'm sure 
>>>> there's customer ECO fixes that aren't reflected in the version, but 
>>>> that's why we have SoC specific compatibles too.) This is the only way 
>>>> we can fix quirks in the OS without doing DT updates. For comparison, do 
>>>> you want to have to update your PC BIOS so an OS can work-around issues?
>>>>
>>> Yes, I understand what you want to say here. But I think this compatible string
>>> does not work with the platform drivers with PCI based systems. So based on the vendor 
>>> id and device id then I need to set the quirk required. 
>>>
>>> @Felipe: What do you suggest for setting up quirk without the DT update for dwc3?
>>
>> We have been using Synopsys controller's revision register, but that's
>> not visible to xhci driver and we don't have a separate compatible for
>> each synopsys version on the xhci driver side. One option would be to
>> add "snps,xhci-foo-bar" to xhci-plat and use that.
>>
> @Felipe: Thanks for suggestion
> 
> @Mathias: Do you prefer parameter passed this way? I can send the v2 patch set,
> after your input.

should work, I don't see any issues with that.

-Mathias