[PATCH RESEND v3 01/11] usb: early: convert to readl_poll_timeout_atomic()

[PATCH RESEND v3 01/11] usb: early: convert to readl_poll_timeout_atomic()

[Chunfeng Yun]

Use readl_poll_timeout_atomic() to simplify code

Cc: Lu Baolu <baolu.lu@linux.intel.com>
Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
---
v2~v3: no changes
---
 drivers/usb/early/xhci-dbc.c | 14 ++++----------
 1 file changed, 4 insertions(+), 10 deletions(-)

diff --git a/drivers/usb/early/xhci-dbc.c b/drivers/usb/early/xhci-dbc.c
index c050776..be4ecba 100644
--- a/drivers/usb/early/xhci-dbc.c
+++ b/drivers/usb/early/xhci-dbc.c
@@ -14,6 +14,7 @@
 #include <linux/pci_ids.h>
 #include <linux/memblock.h>
 #include <linux/io.h>
+#include <linux/iopoll.h>
 #include <asm/pci-direct.h>
 #include <asm/fixmap.h>
 #include <linux/bcd.h>
@@ -135,16 +136,9 @@ static int handshake(void __iomem *ptr, u32 mask, u32 done, int wait, int delay)
 {
 	u32 result;
 
-	do {
-		result = readl(ptr);
-		result &= mask;
-		if (result == done)
-			return 0;
-		udelay(delay);
-		wait -= delay;
-	} while (wait > 0);
-
-	return -ETIMEDOUT;
+	return readl_poll_timeout_atomic(ptr, result,
+					 ((result & mask) == done),
+					 delay, wait);
 }
 
 static void __init xdbc_bios_handoff(void)
-- 
1.9.1
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[PATCH RESEND v3 02/11] usb: early: ehci-dbgp: convert to readl_poll_timeout_atomic()

[Chunfeng Yun]

Use readl_poll_timeout_atomic() to simplify code

Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Petr Mladek <pmladek@suse.com>
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
---
v2~v3: no changes
---
 drivers/usb/early/ehci-dbgp.c | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/drivers/usb/early/ehci-dbgp.c b/drivers/usb/early/ehci-dbgp.c
index b075dbf..45b42d8 100644
--- a/drivers/usb/early/ehci-dbgp.c
+++ b/drivers/usb/early/ehci-dbgp.c
@@ -15,6 +15,7 @@
 #include <linux/console.h>
 #include <linux/errno.h>
 #include <linux/init.h>
+#include <linux/iopoll.h>
 #include <linux/pci_regs.h>
 #include <linux/pci_ids.h>
 #include <linux/usb/ch9.h>
@@ -161,17 +162,11 @@ static inline u32 dbgp_pid_read_update(u32 x, u32 tok)
 static int dbgp_wait_until_complete(void)
 {
 	u32 ctrl;
-	int loop = DBGP_TIMEOUT;
-
-	do {
-		ctrl = readl(&ehci_debug->control);
-		/* Stop when the transaction is finished */
-		if (ctrl & DBGP_DONE)
-			break;
-		udelay(1);
-	} while (--loop > 0);
+	int ret;
 
-	if (!loop)
+	ret = readl_poll_timeout_atomic(&ehci_debug->control, ctrl,
+				(ctrl & DBGP_DONE), 1, DBGP_TIMEOUT);
+	if (ret)
 		return -DBGP_TIMEOUT;
 
 	/*
-- 
1.9.1
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[PATCH RESEND v3 03/11] usb: pci-quirks: convert to readl_poll_timeout_atomic()

[Chunfeng Yun]

Use readl_poll_timeout_atomic() to simplify code

Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
---
v2~v3: no changes
---
 drivers/usb/host/pci-quirks.c | 13 ++++---------
 1 file changed, 4 insertions(+), 9 deletions(-)

diff --git a/drivers/usb/host/pci-quirks.c b/drivers/usb/host/pci-quirks.c
index b8961c0..8920566 100644
--- a/drivers/usb/host/pci-quirks.c
+++ b/drivers/usb/host/pci-quirks.c
@@ -16,6 +16,7 @@
 #include <linux/export.h>
 #include <linux/acpi.h>
 #include <linux/dmi.h>
+#include <linux/iopoll.h>
 
 #include <soc/bcm2835/raspberrypi-firmware.h>
 
@@ -1012,15 +1013,9 @@ static int handshake(void __iomem *ptr, u32 mask, u32 done,
 {
 	u32	result;
 
-	do {
-		result = readl(ptr);
-		result &= mask;
-		if (result == done)
-			return 0;
-		udelay(delay_usec);
-		wait_usec -= delay_usec;
-	} while (wait_usec > 0);
-	return -ETIMEDOUT;
+	return readl_poll_timeout_atomic(ptr, result,
+					 ((result & mask) == done),
+					 delay_usec, wait_usec);
 }
 
 /*
-- 
1.9.1
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[PATCH RESEND v3 04/11] usb: xhci-rcar: convert to readl_poll_timeout_atomic()

[Chunfeng Yun]

Use readl_poll_timeout_atomic() to simplify code

Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
---
v2~v3: no changes
---
 drivers/usb/host/xhci-rcar.c | 43 ++++++++++++-------------------------------
 1 file changed, 12 insertions(+), 31 deletions(-)

diff --git a/drivers/usb/host/xhci-rcar.c b/drivers/usb/host/xhci-rcar.c
index c1025d3..74f836f 100644
--- a/drivers/usb/host/xhci-rcar.c
+++ b/drivers/usb/host/xhci-rcar.c
@@ -6,6 +6,7 @@
  */
 
 #include <linux/firmware.h>
+#include <linux/iopoll.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/of.h>
@@ -127,8 +128,7 @@ static int xhci_rcar_download_firmware(struct usb_hcd *hcd)
 	void __iomem *regs = hcd->regs;
 	struct xhci_plat_priv *priv = hcd_to_xhci_priv(hcd);
 	const struct firmware *fw;
-	int retval, index, j, time;
-	int timeout = 10000;
+	int retval, index, j;
 	u32 data, val, temp;
 	u32 quirks = 0;
 	const struct soc_device_attribute *attr;
@@ -166,32 +166,19 @@ static int xhci_rcar_download_firmware(struct usb_hcd *hcd)
 		temp |= RCAR_USB3_DL_CTRL_FW_SET_DATA0;
 		writel(temp, regs + RCAR_USB3_DL_CTRL);
 
-		for (time = 0; time < timeout; time++) {
-			val = readl(regs + RCAR_USB3_DL_CTRL);
-			if ((val & RCAR_USB3_DL_CTRL_FW_SET_DATA0) == 0)
-				break;
-			udelay(1);
-		}
-		if (time == timeout) {
-			retval = -ETIMEDOUT;
+		retval = readl_poll_timeout_atomic(regs + RCAR_USB3_DL_CTRL,
+				val, !(val & RCAR_USB3_DL_CTRL_FW_SET_DATA0),
+				1, 10000);
+		if (retval < 0)
 			break;
-		}
 	}
 
 	temp = readl(regs + RCAR_USB3_DL_CTRL);
 	temp &= ~RCAR_USB3_DL_CTRL_ENABLE;
 	writel(temp, regs + RCAR_USB3_DL_CTRL);
 
-	for (time = 0; time < timeout; time++) {
-		val = readl(regs + RCAR_USB3_DL_CTRL);
-		if (val & RCAR_USB3_DL_CTRL_FW_SUCCESS) {
-			retval = 0;
-			break;
-		}
-		udelay(1);
-	}
-	if (time == timeout)
-		retval = -ETIMEDOUT;
+	retval = readl_poll_timeout_atomic((regs + RCAR_USB3_DL_CTRL),
+			val, (val & RCAR_USB3_DL_CTRL_FW_SUCCESS), 1, 10000);
 
 	release_firmware(fw);
 
@@ -200,18 +187,12 @@ static int xhci_rcar_download_firmware(struct usb_hcd *hcd)
 
 static bool xhci_rcar_wait_for_pll_active(struct usb_hcd *hcd)
 {
-	int timeout = 1000;
+	int retval;
 	u32 val, mask = RCAR_USB3_AXH_STA_PLL_ACTIVE_MASK;
 
-	while (timeout > 0) {
-		val = readl(hcd->regs + RCAR_USB3_AXH_STA);
-		if ((val & mask) == mask)
-			return true;
-		udelay(1);
-		timeout--;
-	}
-
-	return false;
+	retval = readl_poll_timeout_atomic(hcd->regs + RCAR_USB3_AXH_STA,
+			val, ((val & mask) == mask), 1, 1000);
+	return !!retval;
 }
 
 /* This function needs to initialize a "phy" of usb before */
-- 
1.9.1
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[PATCH RESEND v3 05/11] usb: oxu210hp-hcd: convert to readl_poll_timeout_atomic()

[Chunfeng Yun]

Use readl_poll_timeout_atomic() to simplify code

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
---
v2~v3: no changes
---
 drivers/usb/host/oxu210hp-hcd.c | 21 ++++++++++-----------
 1 file changed, 10 insertions(+), 11 deletions(-)

diff --git a/drivers/usb/host/oxu210hp-hcd.c b/drivers/usb/host/oxu210hp-hcd.c
index cfa7dd2..27dbbe1 100644
--- a/drivers/usb/host/oxu210hp-hcd.c
+++ b/drivers/usb/host/oxu210hp-hcd.c
@@ -24,6 +24,7 @@
 #include <linux/moduleparam.h>
 #include <linux/dma-mapping.h>
 #include <linux/io.h>
+#include <linux/iopoll.h>
 
 #include <asm/irq.h>
 #include <asm/unaligned.h>
@@ -748,18 +749,16 @@ static int handshake(struct oxu_hcd *oxu, void __iomem *ptr,
 					u32 mask, u32 done, int usec)
 {
 	u32 result;
+	int ret;
 
-	do {
-		result = readl(ptr);
-		if (result == ~(u32)0)		/* card removed */
-			return -ENODEV;
-		result &= mask;
-		if (result == done)
-			return 0;
-		udelay(1);
-		usec--;
-	} while (usec > 0);
-	return -ETIMEDOUT;
+	ret = readl_poll_timeout_atomic(ptr, result,
+					((result & mask) == done ||
+					 result == U32_MAX),
+					1, usec);
+	if (result == U32_MAX)		/* card removed */
+		return -ENODEV;
+
+	return ret;
 }
 
 /* Force HC to halt state from unknown (EHCI spec section 2.3) */
-- 
1.9.1
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[PATCH RESEND v3 06/11] usb: fotg210-hcd: convert to readl_poll_timeout_atomic()

[Chunfeng Yun]

Use readl_poll_timeout_atomic() to simplify code

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
---
v2~v3: no changes
---
 drivers/usb/host/fotg210-hcd.c | 20 +++++++++-----------
 1 file changed, 9 insertions(+), 11 deletions(-)

diff --git a/drivers/usb/host/fotg210-hcd.c b/drivers/usb/host/fotg210-hcd.c
index 194df82..1d94fcf 100644
--- a/drivers/usb/host/fotg210-hcd.c
+++ b/drivers/usb/host/fotg210-hcd.c
@@ -32,6 +32,7 @@
 #include <linux/uaccess.h>
 #include <linux/platform_device.h>
 #include <linux/io.h>
+#include <linux/iopoll.h>
 #include <linux/clk.h>
 
 #include <asm/byteorder.h>
@@ -883,18 +884,15 @@ static int handshake(struct fotg210_hcd *fotg210, void __iomem *ptr,
 		u32 mask, u32 done, int usec)
 {
 	u32 result;
+	int ret;
 
-	do {
-		result = fotg210_readl(fotg210, ptr);
-		if (result == ~(u32)0)		/* card removed */
-			return -ENODEV;
-		result &= mask;
-		if (result == done)
-			return 0;
-		udelay(1);
-		usec--;
-	} while (usec > 0);
-	return -ETIMEDOUT;
+	ret = readl_poll_timeout_atomic(ptr, result,
+					((result & mask) == done ||
+					 result == U32_MAX), 1, usec);
+	if (result == U32_MAX)		/* card removed */
+		return -ENODEV;
+
+	return ret;
 }
 
 /* Force HC to halt state from unknown (EHCI spec section 2.3).
-- 
1.9.1
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[PATCH RESEND v3 07/11] usb: isp1760-hcd: convert to readl_poll_timeout_atomic()

[Chunfeng Yun]

Use readl_poll_timeout_atomic() to simplify code

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
---
v2~v3: no changes
---
 drivers/usb/isp1760/isp1760-hcd.c | 20 +++++++++-----------
 1 file changed, 9 insertions(+), 11 deletions(-)

diff --git a/drivers/usb/isp1760/isp1760-hcd.c b/drivers/usb/isp1760/isp1760-hcd.c
index dd74ab7a..33ae656 100644
--- a/drivers/usb/isp1760/isp1760-hcd.c
+++ b/drivers/usb/isp1760/isp1760-hcd.c
@@ -22,6 +22,7 @@
 #include <linux/debugfs.h>
 #include <linux/uaccess.h>
 #include <linux/io.h>
+#include <linux/iopoll.h>
 #include <linux/mm.h>
 #include <linux/timer.h>
 #include <asm/unaligned.h>
@@ -380,18 +381,15 @@ static int handshake(struct usb_hcd *hcd, u32 reg,
 		      u32 mask, u32 done, int usec)
 {
 	u32 result;
+	int ret;
+
+	ret = readl_poll_timeout_atomic(hcd->regs + reg, result,
+					((result & mask) == done ||
+					 result == U32_MAX), 1, usec);
+	if (result == U32_MAX)
+		return -ENODEV;
 
-	do {
-		result = reg_read32(hcd->regs, reg);
-		if (result == ~0)
-			return -ENODEV;
-		result &= mask;
-		if (result == done)
-			return 0;
-		udelay(1);
-		usec--;
-	} while (usec > 0);
-	return -ETIMEDOUT;
+	return ret;
 }
 
 /* reset a non-running (STS_HALT == 1) controller */
-- 
1.9.1
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[PATCH RESEND v3 08/11] usb: phy-ulpi-viewport: convert to readl_poll_timeout_atomic()

[Chunfeng Yun]

Use readl_poll_timeout_atomic() to simplify code

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
---
v2~v3: no changes
---
 drivers/usb/phy/phy-ulpi-viewport.c | 12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/drivers/usb/phy/phy-ulpi-viewport.c b/drivers/usb/phy/phy-ulpi-viewport.c
index 7a14e0e..0f61e32 100644
--- a/drivers/usb/phy/phy-ulpi-viewport.c
+++ b/drivers/usb/phy/phy-ulpi-viewport.c
@@ -7,6 +7,7 @@
 #include <linux/kernel.h>
 #include <linux/usb.h>
 #include <linux/io.h>
+#include <linux/iopoll.h>
 #include <linux/usb/otg.h>
 #include <linux/usb/ulpi.h>
 
@@ -20,16 +21,9 @@
 
 static int ulpi_viewport_wait(void __iomem *view, u32 mask)
 {
-	unsigned long usec = 2000;
+	u32 val;
 
-	while (usec--) {
-		if (!(readl(view) & mask))
-			return 0;
-
-		udelay(1);
-	}
-
-	return -ETIMEDOUT;
+	return readl_poll_timeout_atomic(view, val, !(val & mask), 1, 2000);
 }
 
 static int ulpi_viewport_read(struct usb_phy *otg, u32 reg)
-- 
1.9.1
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[PATCH RESEND v3 09/11] usb: phy: phy-mv-usb: convert to readl_poll_timeout_atomic()

[Chunfeng Yun]

Use readl_poll_timeout_atomic() to simplify code

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
---
v3: re-align argument of log suggested by Sergei

v2: udelay 10us instead of 20us according to kerneldoc
---
 drivers/usb/phy/phy-mv-usb.c | 18 ++++++++----------
 1 file changed, 8 insertions(+), 10 deletions(-)

diff --git a/drivers/usb/phy/phy-mv-usb.c b/drivers/usb/phy/phy-mv-usb.c
index ce767ec..576d925 100644
--- a/drivers/usb/phy/phy-mv-usb.c
+++ b/drivers/usb/phy/phy-mv-usb.c
@@ -8,6 +8,7 @@
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/io.h>
+#include <linux/iopoll.h>
 #include <linux/uaccess.h>
 #include <linux/device.h>
 #include <linux/proc_fs.h>
@@ -135,8 +136,8 @@ static int mv_otg_set_timer(struct mv_otg *mvotg, unsigned int id,
 
 static int mv_otg_reset(struct mv_otg *mvotg)
 {
-	unsigned int loops;
 	u32 tmp;
+	int ret;
 
 	/* Stop the controller */
 	tmp = readl(&mvotg->op_regs->usbcmd);
@@ -146,15 +147,12 @@ static int mv_otg_reset(struct mv_otg *mvotg)
 	/* Reset the controller to get default values */
 	writel(USBCMD_CTRL_RESET, &mvotg->op_regs->usbcmd);
 
-	loops = 500;
-	while (readl(&mvotg->op_regs->usbcmd) & USBCMD_CTRL_RESET) {
-		if (loops == 0) {
-			dev_err(&mvotg->pdev->dev,
-				"Wait for RESET completed TIMEOUT\n");
-			return -ETIMEDOUT;
-		}
-		loops--;
-		udelay(20);
+	ret = readl_poll_timeout_atomic(&mvotg->op_regs->usbcmd, tmp,
+				(tmp & USBCMD_CTRL_RESET), 10, 10000);
+	if (ret < 0) {
+		dev_err(&mvotg->pdev->dev,
+			"Wait for RESET completed TIMEOUT\n");
+		return ret;
 	}
 
 	writel(0x0, &mvotg->op_regs->usbintr);
-- 
1.9.1
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[PATCH RESEND v3 10/11] usb: udc: net2280: convert to readl_poll_timeout_atomic()

[Chunfeng Yun]

Use readl_poll_timeout_atomic() to simplify code

Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
---
v3: no changes

v2: add Acked-by Alan
---
 drivers/usb/gadget/udc/net2280.c | 21 ++++++++++-----------
 1 file changed, 10 insertions(+), 11 deletions(-)

diff --git a/drivers/usb/gadget/udc/net2280.c b/drivers/usb/gadget/udc/net2280.c
index 7530bd9..f1a21f4 100644
--- a/drivers/usb/gadget/udc/net2280.c
+++ b/drivers/usb/gadget/udc/net2280.c
@@ -52,6 +52,7 @@
 #include <linux/usb/gadget.h>
 #include <linux/prefetch.h>
 #include <linux/io.h>
+#include <linux/iopoll.h>
 
 #include <asm/byteorder.h>
 #include <asm/irq.h>
@@ -360,18 +361,16 @@ static inline void enable_pciirqenb(struct net2280_ep *ep)
 static int handshake(u32 __iomem *ptr, u32 mask, u32 done, int usec)
 {
 	u32	result;
+	int	ret;
 
-	do {
-		result = readl(ptr);
-		if (result == ~(u32)0)		/* "device unplugged" */
-			return -ENODEV;
-		result &= mask;
-		if (result == done)
-			return 0;
-		udelay(1);
-		usec--;
-	} while (usec > 0);
-	return -ETIMEDOUT;
+	ret = readl_poll_timeout_atomic(ptr, result,
+					((result & mask) == done ||
+					 result == U32_MAX),
+					1, usec);
+	if (result == U32_MAX)		/* device unplugged */
+		return -ENODEV;
+
+	return ret;
 }
 
 static const struct usb_ep_ops net2280_ep_ops;
-- 
1.9.1
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[PATCH RESEND v3 11/11] iopoll: update kerneldoc of read_poll_timeout_atomic()

[Chunfeng Yun]

Arguments description of read_poll_timeout_atomic() is out of date,
update it.

Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
---
v3: fix typo in commit message suggested by Sergei

v2: new patch, suggested by Alan
---
 include/linux/iopoll.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/linux/iopoll.h b/include/linux/iopoll.h
index bc89ac6..2c8860e 100644
--- a/include/linux/iopoll.h
+++ b/include/linux/iopoll.h
@@ -60,8 +60,7 @@
 /**
  * read_poll_timeout_atomic - Periodically poll an address until a condition is
  * 				met or a timeout occurs
- * @op: accessor function (takes @addr as its only argument)
- * @addr: Address to poll
+ * @op: accessor function (takes @args as its arguments)
  * @val: Variable to read the value into
  * @cond: Break condition (usually involving @val)
  * @delay_us: Time to udelay between reads in us (0 tight-loops).  Should
@@ -69,6 +68,7 @@
  *            Documentation/timers/timers-howto.rst).
  * @timeout_us: Timeout in us, 0 means never timeout
  * @delay_before_read: if it is true, delay @delay_us before read.
+ * @args: arguments for @op poll
  *
  * Returns 0 on success and -ETIMEDOUT upon a timeout. In either
  * case, the last read value at @args is stored in @val.
-- 
1.9.1
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Re: [PATCH RESEND v3 01/11] usb: early: convert to readl_poll_timeout_atomic()

[Jann Horn]

On Thu, Sep 10, 2020 at 10:24 AM Chunfeng Yun <chunfeng.yun@mediatek.com> wrote:
> Use readl_poll_timeout_atomic() to simplify code
>
> Cc: Lu Baolu <baolu.lu@linux.intel.com>
> Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
> Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>

Reviewed-by: Jann Horn <jannh@google.com>

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RE: [PATCH RESEND v3 04/11] usb: xhci-rcar: convert to readl_poll_timeout_atomic()

[Yoshihiro Shimoda]

Hi Chunfeng,

Thank you for the patch!

> From: Chunfeng Yun, Sent: Thursday, September 10, 2020 5:22 PM
> 
> Use readl_poll_timeout_atomic() to simplify code
> 
> Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
> Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
> ---
> v2~v3: no changes
> ---
>  drivers/usb/host/xhci-rcar.c | 43 ++++++++++++-------------------------------
>  1 file changed, 12 insertions(+), 31 deletions(-)
> 
> diff --git a/drivers/usb/host/xhci-rcar.c b/drivers/usb/host/xhci-rcar.c
> index c1025d3..74f836f 100644
> --- a/drivers/usb/host/xhci-rcar.c
> +++ b/drivers/usb/host/xhci-rcar.c
> @@ -6,6 +6,7 @@
>   */
> 
>  #include <linux/firmware.h>
> +#include <linux/iopoll.h>
>  #include <linux/module.h>
>  #include <linux/platform_device.h>
>  #include <linux/of.h>
> @@ -127,8 +128,7 @@ static int xhci_rcar_download_firmware(struct usb_hcd *hcd)
>  	void __iomem *regs = hcd->regs;
>  	struct xhci_plat_priv *priv = hcd_to_xhci_priv(hcd);
>  	const struct firmware *fw;
> -	int retval, index, j, time;
> -	int timeout = 10000;
> +	int retval, index, j;
>  	u32 data, val, temp;
>  	u32 quirks = 0;
>  	const struct soc_device_attribute *attr;
> @@ -166,32 +166,19 @@ static int xhci_rcar_download_firmware(struct usb_hcd *hcd)
>  		temp |= RCAR_USB3_DL_CTRL_FW_SET_DATA0;
>  		writel(temp, regs + RCAR_USB3_DL_CTRL);
> 
> -		for (time = 0; time < timeout; time++) {
> -			val = readl(regs + RCAR_USB3_DL_CTRL);
> -			if ((val & RCAR_USB3_DL_CTRL_FW_SET_DATA0) == 0)
> -				break;
> -			udelay(1);
> -		}
> -		if (time == timeout) {
> -			retval = -ETIMEDOUT;
> +		retval = readl_poll_timeout_atomic(regs + RCAR_USB3_DL_CTRL,
> +				val, !(val & RCAR_USB3_DL_CTRL_FW_SET_DATA0),
> +				1, 10000);
> +		if (retval < 0)
>  			break;
> -		}
>  	}
> 
>  	temp = readl(regs + RCAR_USB3_DL_CTRL);
>  	temp &= ~RCAR_USB3_DL_CTRL_ENABLE;
>  	writel(temp, regs + RCAR_USB3_DL_CTRL);
> 
> -	for (time = 0; time < timeout; time++) {
> -		val = readl(regs + RCAR_USB3_DL_CTRL);
> -		if (val & RCAR_USB3_DL_CTRL_FW_SUCCESS) {
> -			retval = 0;
> -			break;
> -		}
> -		udelay(1);
> -	}
> -	if (time == timeout)
> -		retval = -ETIMEDOUT;
> +	retval = readl_poll_timeout_atomic((regs + RCAR_USB3_DL_CTRL),
> +			val, (val & RCAR_USB3_DL_CTRL_FW_SUCCESS), 1, 10000);

Some parentheses are not needed like below:

	retval = readl_poll_timeout_atomic(regs + RCAR_USB3_DL_CTRL,
			val, val & RCAR_USB3_DL_CTRL_FW_SUCCESS, 1, 10000);


>  	release_firmware(fw);
> 
> @@ -200,18 +187,12 @@ static int xhci_rcar_download_firmware(struct usb_hcd *hcd)
> 
>  static bool xhci_rcar_wait_for_pll_active(struct usb_hcd *hcd)
>  {
> -	int timeout = 1000;
> +	int retval;
>  	u32 val, mask = RCAR_USB3_AXH_STA_PLL_ACTIVE_MASK;
> 
> -	while (timeout > 0) {
> -		val = readl(hcd->regs + RCAR_USB3_AXH_STA);
> -		if ((val & mask) == mask)
> -			return true;
> -		udelay(1);
> -		timeout--;
> -	}
> -
> -	return false;
> +	retval = readl_poll_timeout_atomic(hcd->regs + RCAR_USB3_AXH_STA,
> +			val, ((val & mask) == mask), 1, 1000);

Likewise above:
	retval = readl_poll_timeout_atomic(hcd->regs + RCAR_USB3_AXH_STA,
			val, (val & mask) == mask, 1, 1000);

> +	return !!retval;

This breaks the code. If I changed this to "return retval < 0 ? false : true;",
it works again.

Best regards,
Yoshihiro Shimoda


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Re: [PATCH RESEND v3 04/11] usb: xhci-rcar: convert to readl_poll_timeout_atomic()

[Daniel Thompson]

On Thu, Sep 10, 2020 at 04:21:45PM +0800, Chunfeng Yun wrote:
> Use readl_poll_timeout_atomic() to simplify code
> 
> Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
> Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
> ---
> v2~v3: no changes
> ---
>  drivers/usb/host/xhci-rcar.c | 43 ++++++++++++-------------------------------
>  1 file changed, 12 insertions(+), 31 deletions(-)
> 
> diff --git a/drivers/usb/host/xhci-rcar.c b/drivers/usb/host/xhci-rcar.c
> index c1025d3..74f836f 100644
> --- a/drivers/usb/host/xhci-rcar.c
> +++ b/drivers/usb/host/xhci-rcar.c
> @@ -6,6 +6,7 @@
>   */
>  
>  #include <linux/firmware.h>
> +#include <linux/iopoll.h>
>  #include <linux/module.h>
>  #include <linux/platform_device.h>
>  #include <linux/of.h>
> @@ -127,8 +128,7 @@ static int xhci_rcar_download_firmware(struct usb_hcd *hcd)
>  	void __iomem *regs = hcd->regs;
>  	struct xhci_plat_priv *priv = hcd_to_xhci_priv(hcd);
>  	const struct firmware *fw;
> -	int retval, index, j, time;
> -	int timeout = 10000;
> +	int retval, index, j;
>  	u32 data, val, temp;
>  	u32 quirks = 0;
>  	const struct soc_device_attribute *attr;
> @@ -166,32 +166,19 @@ static int xhci_rcar_download_firmware(struct usb_hcd *hcd)
>  		temp |= RCAR_USB3_DL_CTRL_FW_SET_DATA0;
>  		writel(temp, regs + RCAR_USB3_DL_CTRL);
>  
> -		for (time = 0; time < timeout; time++) {
> -			val = readl(regs + RCAR_USB3_DL_CTRL);
> -			if ((val & RCAR_USB3_DL_CTRL_FW_SET_DATA0) == 0)
> -				break;
> -			udelay(1);
> -		}
> -		if (time == timeout) {
> -			retval = -ETIMEDOUT;
> +		retval = readl_poll_timeout_atomic(regs + RCAR_USB3_DL_CTRL,
> +				val, !(val & RCAR_USB3_DL_CTRL_FW_SET_DATA0),
> +				1, 10000);
> +		if (retval < 0)
>  			break;
> -		}
>  	}
>  
>  	temp = readl(regs + RCAR_USB3_DL_CTRL);
>  	temp &= ~RCAR_USB3_DL_CTRL_ENABLE;
>  	writel(temp, regs + RCAR_USB3_DL_CTRL);
>  
> -	for (time = 0; time < timeout; time++) {
> -		val = readl(regs + RCAR_USB3_DL_CTRL);
> -		if (val & RCAR_USB3_DL_CTRL_FW_SUCCESS) {
> -			retval = 0;
> -			break;
> -		}
> -		udelay(1);
> -	}
> -	if (time == timeout)
> -		retval = -ETIMEDOUT;
> +	retval = readl_poll_timeout_atomic((regs + RCAR_USB3_DL_CTRL),
> +			val, (val & RCAR_USB3_DL_CTRL_FW_SUCCESS), 1, 10000);

Directly assigning to retval at this point will clobber a previous
-ETIMEDOUT error.

In other words if there is a timeout waiting for FW_SET_DATA0, but not for
DW_SUCCESS, then we will return the wrong return value.


Daniel.


>  
>  	release_firmware(fw);
>  
> @@ -200,18 +187,12 @@ static int xhci_rcar_download_firmware(struct usb_hcd *hcd)
>  
>  static bool xhci_rcar_wait_for_pll_active(struct usb_hcd *hcd)
>  {
> -	int timeout = 1000;
> +	int retval;
>  	u32 val, mask = RCAR_USB3_AXH_STA_PLL_ACTIVE_MASK;
>  
> -	while (timeout > 0) {
> -		val = readl(hcd->regs + RCAR_USB3_AXH_STA);
> -		if ((val & mask) == mask)
> -			return true;
> -		udelay(1);
> -		timeout--;
> -	}
> -
> -	return false;
> +	retval = readl_poll_timeout_atomic(hcd->regs + RCAR_USB3_AXH_STA,
> +			val, ((val & mask) == mask), 1, 1000);
> +	return !!retval;

This function returns a bool so !! is either wrong or redundant... I
think in this case it is wrong and should be a single ! .


Daniel.

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Re: [PATCH RESEND v3 04/11] usb: xhci-rcar: convert to readl_poll_timeout_atomic()

[Chunfeng Yun]

On Thu, 2020-09-10 at 12:56 +0000, Yoshihiro Shimoda wrote:
> Hi Chunfeng,
> 
> Thank you for the patch!
> 
> > From: Chunfeng Yun, Sent: Thursday, September 10, 2020 5:22 PM
> > 
> > Use readl_poll_timeout_atomic() to simplify code
> > 
> > Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
> > Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> > Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
> > ---
> > v2~v3: no changes
> > ---
> >  drivers/usb/host/xhci-rcar.c | 43 ++++++++++++-------------------------------
> >  1 file changed, 12 insertions(+), 31 deletions(-)
> > 
> > diff --git a/drivers/usb/host/xhci-rcar.c b/drivers/usb/host/xhci-rcar.c
> > index c1025d3..74f836f 100644
> > --- a/drivers/usb/host/xhci-rcar.c
> > +++ b/drivers/usb/host/xhci-rcar.c
> > @@ -6,6 +6,7 @@
> >   */
> > 
> >  #include <linux/firmware.h>
> > +#include <linux/iopoll.h>
> >  #include <linux/module.h>
> >  #include <linux/platform_device.h>
> >  #include <linux/of.h>
> > @@ -127,8 +128,7 @@ static int xhci_rcar_download_firmware(struct usb_hcd *hcd)
> >  	void __iomem *regs = hcd->regs;
> >  	struct xhci_plat_priv *priv = hcd_to_xhci_priv(hcd);
> >  	const struct firmware *fw;
> > -	int retval, index, j, time;
> > -	int timeout = 10000;
> > +	int retval, index, j;
> >  	u32 data, val, temp;
> >  	u32 quirks = 0;
> >  	const struct soc_device_attribute *attr;
> > @@ -166,32 +166,19 @@ static int xhci_rcar_download_firmware(struct usb_hcd *hcd)
> >  		temp |= RCAR_USB3_DL_CTRL_FW_SET_DATA0;
> >  		writel(temp, regs + RCAR_USB3_DL_CTRL);
> > 
> > -		for (time = 0; time < timeout; time++) {
> > -			val = readl(regs + RCAR_USB3_DL_CTRL);
> > -			if ((val & RCAR_USB3_DL_CTRL_FW_SET_DATA0) == 0)
> > -				break;
> > -			udelay(1);
> > -		}
> > -		if (time == timeout) {
> > -			retval = -ETIMEDOUT;
> > +		retval = readl_poll_timeout_atomic(regs + RCAR_USB3_DL_CTRL,
> > +				val, !(val & RCAR_USB3_DL_CTRL_FW_SET_DATA0),
> > +				1, 10000);
> > +		if (retval < 0)
> >  			break;
> > -		}
> >  	}
> > 
> >  	temp = readl(regs + RCAR_USB3_DL_CTRL);
> >  	temp &= ~RCAR_USB3_DL_CTRL_ENABLE;
> >  	writel(temp, regs + RCAR_USB3_DL_CTRL);
> > 
> > -	for (time = 0; time < timeout; time++) {
> > -		val = readl(regs + RCAR_USB3_DL_CTRL);
> > -		if (val & RCAR_USB3_DL_CTRL_FW_SUCCESS) {
> > -			retval = 0;
> > -			break;
> > -		}
> > -		udelay(1);
> > -	}
> > -	if (time == timeout)
> > -		retval = -ETIMEDOUT;
> > +	retval = readl_poll_timeout_atomic((regs + RCAR_USB3_DL_CTRL),
> > +			val, (val & RCAR_USB3_DL_CTRL_FW_SUCCESS), 1, 10000);
> 
> Some parentheses are not needed like below:
> 
> 	retval = readl_poll_timeout_atomic(regs + RCAR_USB3_DL_CTRL,
> 			val, val & RCAR_USB3_DL_CTRL_FW_SUCCESS, 1, 10000);
> 
Ok, will modify it

> 
> >  	release_firmware(fw);
> > 
> > @@ -200,18 +187,12 @@ static int xhci_rcar_download_firmware(struct usb_hcd *hcd)
> > 
> >  static bool xhci_rcar_wait_for_pll_active(struct usb_hcd *hcd)
> >  {
> > -	int timeout = 1000;
> > +	int retval;
> >  	u32 val, mask = RCAR_USB3_AXH_STA_PLL_ACTIVE_MASK;
> > 
> > -	while (timeout > 0) {
> > -		val = readl(hcd->regs + RCAR_USB3_AXH_STA);
> > -		if ((val & mask) == mask)
> > -			return true;
> > -		udelay(1);
> > -		timeout--;
> > -	}
> > -
> > -	return false;
> > +	retval = readl_poll_timeout_atomic(hcd->regs + RCAR_USB3_AXH_STA,
> > +			val, ((val & mask) == mask), 1, 1000);
> 
> Likewise above:
> 	retval = readl_poll_timeout_atomic(hcd->regs + RCAR_USB3_AXH_STA,
> 			val, (val & mask) == mask, 1, 1000);
> 
> > +	return !!retval;
> 
> This breaks the code. If I changed this to "return retval < 0 ? false : true;",
> it works again.
Oops, my bad, will fix it

Thanks a lot

> 
> Best regards,
> Yoshihiro Shimoda
> 

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Re: [PATCH RESEND v3 04/11] usb: xhci-rcar: convert to readl_poll_timeout_atomic()

[Chunfeng Yun]

On Thu, 2020-09-10 at 14:12 +0100, Daniel Thompson wrote:
> On Thu, Sep 10, 2020 at 04:21:45PM +0800, Chunfeng Yun wrote:
> > Use readl_poll_timeout_atomic() to simplify code
> > 
> > Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
> > Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> > Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
> > ---
> > v2~v3: no changes
> > ---
> >  drivers/usb/host/xhci-rcar.c | 43 ++++++++++++-------------------------------
> >  1 file changed, 12 insertions(+), 31 deletions(-)
> > 
> > diff --git a/drivers/usb/host/xhci-rcar.c b/drivers/usb/host/xhci-rcar.c
> > index c1025d3..74f836f 100644
> > --- a/drivers/usb/host/xhci-rcar.c
> > +++ b/drivers/usb/host/xhci-rcar.c
> > @@ -6,6 +6,7 @@
> >   */
> >  
> >  #include <linux/firmware.h>
> > +#include <linux/iopoll.h>
> >  #include <linux/module.h>
> >  #include <linux/platform_device.h>
> >  #include <linux/of.h>
> > @@ -127,8 +128,7 @@ static int xhci_rcar_download_firmware(struct usb_hcd *hcd)
> >  	void __iomem *regs = hcd->regs;
> >  	struct xhci_plat_priv *priv = hcd_to_xhci_priv(hcd);
> >  	const struct firmware *fw;
> > -	int retval, index, j, time;
> > -	int timeout = 10000;
> > +	int retval, index, j;
> >  	u32 data, val, temp;
> >  	u32 quirks = 0;
> >  	const struct soc_device_attribute *attr;
> > @@ -166,32 +166,19 @@ static int xhci_rcar_download_firmware(struct usb_hcd *hcd)
> >  		temp |= RCAR_USB3_DL_CTRL_FW_SET_DATA0;
> >  		writel(temp, regs + RCAR_USB3_DL_CTRL);
> >  
> > -		for (time = 0; time < timeout; time++) {
> > -			val = readl(regs + RCAR_USB3_DL_CTRL);
> > -			if ((val & RCAR_USB3_DL_CTRL_FW_SET_DATA0) == 0)
> > -				break;
> > -			udelay(1);
> > -		}
> > -		if (time == timeout) {
> > -			retval = -ETIMEDOUT;
> > +		retval = readl_poll_timeout_atomic(regs + RCAR_USB3_DL_CTRL,
> > +				val, !(val & RCAR_USB3_DL_CTRL_FW_SET_DATA0),
> > +				1, 10000);
> > +		if (retval < 0)
> >  			break;
> > -		}
> >  	}
> >  
> >  	temp = readl(regs + RCAR_USB3_DL_CTRL);
> >  	temp &= ~RCAR_USB3_DL_CTRL_ENABLE;
> >  	writel(temp, regs + RCAR_USB3_DL_CTRL);
> >  
> > -	for (time = 0; time < timeout; time++) {
> > -		val = readl(regs + RCAR_USB3_DL_CTRL);
> > -		if (val & RCAR_USB3_DL_CTRL_FW_SUCCESS) {
> > -			retval = 0;
> > -			break;
> > -		}
> > -		udelay(1);
> > -	}
> > -	if (time == timeout)
> > -		retval = -ETIMEDOUT;
> > +	retval = readl_poll_timeout_atomic((regs + RCAR_USB3_DL_CTRL),
> > +			val, (val & RCAR_USB3_DL_CTRL_FW_SUCCESS), 1, 10000);
> 
> Directly assigning to retval at this point will clobber a previous
> -ETIMEDOUT error.
> 
> In other words if there is a timeout waiting for FW_SET_DATA0, but not for
> DW_SUCCESS, then we will return the wrong return value.
Yes, agree with you, but seems I keep its original logic unchanged.

Hi Yoshihiro,

  What do think about Daniel's suggestion? should I fix it up?

> 
> 
> Daniel.
> 
> 
> >  
> >  	release_firmware(fw);
> >  
> > @@ -200,18 +187,12 @@ static int xhci_rcar_download_firmware(struct usb_hcd *hcd)
> >  
> >  static bool xhci_rcar_wait_for_pll_active(struct usb_hcd *hcd)
> >  {
> > -	int timeout = 1000;
> > +	int retval;
> >  	u32 val, mask = RCAR_USB3_AXH_STA_PLL_ACTIVE_MASK;
> >  
> > -	while (timeout > 0) {
> > -		val = readl(hcd->regs + RCAR_USB3_AXH_STA);
> > -		if ((val & mask) == mask)
> > -			return true;
> > -		udelay(1);
> > -		timeout--;
> > -	}
> > -
> > -	return false;
> > +	retval = readl_poll_timeout_atomic(hcd->regs + RCAR_USB3_AXH_STA,
> > +			val, ((val & mask) == mask), 1, 1000);
> > +	return !!retval;
> 
> This function returns a bool so !! is either wrong or redundant... I
> think in this case it is wrong and should be a single ! .
Yes, will fix it

Thanks a lot
> 
> 
> Daniel.

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RE: [PATCH RESEND v3 04/11] usb: xhci-rcar: convert to readl_poll_timeout_atomic()

[Yoshihiro Shimoda]

Hi Daniel, Chunfeng,

> From: Chunfeng Yun, Sent: Friday, September 11, 2020 11:33 AM
> 
> On Thu, 2020-09-10 at 14:12 +0100, Daniel Thompson wrote:
> > On Thu, Sep 10, 2020 at 04:21:45PM +0800, Chunfeng Yun wrote:
> > > Use readl_poll_timeout_atomic() to simplify code
> > >
> > > Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
> > > Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> > > Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
> > > ---
> > > v2~v3: no changes
> > > ---
> > >  drivers/usb/host/xhci-rcar.c | 43 ++++++++++++-------------------------------
> > >  1 file changed, 12 insertions(+), 31 deletions(-)
> > >
> > > diff --git a/drivers/usb/host/xhci-rcar.c b/drivers/usb/host/xhci-rcar.c
> > > index c1025d3..74f836f 100644
> > > --- a/drivers/usb/host/xhci-rcar.c
> > > +++ b/drivers/usb/host/xhci-rcar.c
> > > @@ -6,6 +6,7 @@
> > >   */
> > >
> > >  #include <linux/firmware.h>
> > > +#include <linux/iopoll.h>
> > >  #include <linux/module.h>
> > >  #include <linux/platform_device.h>
> > >  #include <linux/of.h>
> > > @@ -127,8 +128,7 @@ static int xhci_rcar_download_firmware(struct usb_hcd *hcd)
> > >  	void __iomem *regs = hcd->regs;
> > >  	struct xhci_plat_priv *priv = hcd_to_xhci_priv(hcd);
> > >  	const struct firmware *fw;
> > > -	int retval, index, j, time;
> > > -	int timeout = 10000;
> > > +	int retval, index, j;
> > >  	u32 data, val, temp;
> > >  	u32 quirks = 0;
> > >  	const struct soc_device_attribute *attr;
> > > @@ -166,32 +166,19 @@ static int xhci_rcar_download_firmware(struct usb_hcd *hcd)
> > >  		temp |= RCAR_USB3_DL_CTRL_FW_SET_DATA0;
> > >  		writel(temp, regs + RCAR_USB3_DL_CTRL);
> > >
> > > -		for (time = 0; time < timeout; time++) {
> > > -			val = readl(regs + RCAR_USB3_DL_CTRL);
> > > -			if ((val & RCAR_USB3_DL_CTRL_FW_SET_DATA0) == 0)
> > > -				break;
> > > -			udelay(1);
> > > -		}
> > > -		if (time == timeout) {
> > > -			retval = -ETIMEDOUT;
> > > +		retval = readl_poll_timeout_atomic(regs + RCAR_USB3_DL_CTRL,
> > > +				val, !(val & RCAR_USB3_DL_CTRL_FW_SET_DATA0),
> > > +				1, 10000);
> > > +		if (retval < 0)
> > >  			break;
> > > -		}
> > >  	}
> > >
> > >  	temp = readl(regs + RCAR_USB3_DL_CTRL);
> > >  	temp &= ~RCAR_USB3_DL_CTRL_ENABLE;
> > >  	writel(temp, regs + RCAR_USB3_DL_CTRL);
> > >
> > > -	for (time = 0; time < timeout; time++) {
> > > -		val = readl(regs + RCAR_USB3_DL_CTRL);
> > > -		if (val & RCAR_USB3_DL_CTRL_FW_SUCCESS) {
> > > -			retval = 0;
> > > -			break;
> > > -		}
> > > -		udelay(1);
> > > -	}
> > > -	if (time == timeout)
> > > -		retval = -ETIMEDOUT;
> > > +	retval = readl_poll_timeout_atomic((regs + RCAR_USB3_DL_CTRL),
> > > +			val, (val & RCAR_USB3_DL_CTRL_FW_SUCCESS), 1, 10000);
> >
> > Directly assigning to retval at this point will clobber a previous
> > -ETIMEDOUT error.
> >
> > In other words if there is a timeout waiting for FW_SET_DATA0, but not for
> > DW_SUCCESS, then we will return the wrong return value.

Thank you for your comment! I didn't realized this.

> Yes, agree with you, but seems I keep its original logic unchanged.
> Hi Yoshihiro,
> 
>   What do think about Daniel's suggestion? should I fix it up?

I think you should fix it up like below:

if (readl_poll_timeout_atomic(regs + RCAR_USB3_DL_CTRL,
		val, val & RCAR_USB3_DL_CTRL_FW_SUCCESS, 1, 10000) < 0)
	retval = -ETIMEOUT;	/* Overwrite retval if timeout occurred */

Otherwise, the xhci_rcar_download_firmware() cannot return -ETIMEDOUT if
timeout happened on the previous poll [1].

[1]
+		retval = readl_poll_timeout_atomic(regs + RCAR_USB3_DL_CTRL,
+				val, !(val & RCAR_USB3_DL_CTRL_FW_SET_DATA0),
+				1, 10000);

Best regards,
Yoshihiro Shimoda

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Re: [PATCH RESEND v3 04/11] usb: xhci-rcar: convert to readl_poll_timeout_atomic()

[Chunfeng Yun]

On Fri, 2020-09-11 at 03:13 +0000, Yoshihiro Shimoda wrote:
> Hi Daniel, Chunfeng,
> 
> > From: Chunfeng Yun, Sent: Friday, September 11, 2020 11:33 AM
> > 
> > On Thu, 2020-09-10 at 14:12 +0100, Daniel Thompson wrote:
> > > On Thu, Sep 10, 2020 at 04:21:45PM +0800, Chunfeng Yun wrote:
> > > > Use readl_poll_timeout_atomic() to simplify code
> > > >
> > > > Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
> > > > Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> > > > Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
> > > > ---
> > > > v2~v3: no changes
> > > > ---
> > > >  drivers/usb/host/xhci-rcar.c | 43 ++++++++++++-------------------------------
> > > >  1 file changed, 12 insertions(+), 31 deletions(-)
> > > >
> > > > diff --git a/drivers/usb/host/xhci-rcar.c b/drivers/usb/host/xhci-rcar.c
> > > > index c1025d3..74f836f 100644
> > > > --- a/drivers/usb/host/xhci-rcar.c
> > > > +++ b/drivers/usb/host/xhci-rcar.c
> > > > @@ -6,6 +6,7 @@
> > > >   */
> > > >
> > > >  #include <linux/firmware.h>
> > > > +#include <linux/iopoll.h>
> > > >  #include <linux/module.h>
> > > >  #include <linux/platform_device.h>
> > > >  #include <linux/of.h>
> > > > @@ -127,8 +128,7 @@ static int xhci_rcar_download_firmware(struct usb_hcd *hcd)
> > > >  	void __iomem *regs = hcd->regs;
> > > >  	struct xhci_plat_priv *priv = hcd_to_xhci_priv(hcd);
> > > >  	const struct firmware *fw;
> > > > -	int retval, index, j, time;
> > > > -	int timeout = 10000;
> > > > +	int retval, index, j;
> > > >  	u32 data, val, temp;
> > > >  	u32 quirks = 0;
> > > >  	const struct soc_device_attribute *attr;
> > > > @@ -166,32 +166,19 @@ static int xhci_rcar_download_firmware(struct usb_hcd *hcd)
> > > >  		temp |= RCAR_USB3_DL_CTRL_FW_SET_DATA0;
> > > >  		writel(temp, regs + RCAR_USB3_DL_CTRL);
> > > >
> > > > -		for (time = 0; time < timeout; time++) {
> > > > -			val = readl(regs + RCAR_USB3_DL_CTRL);
> > > > -			if ((val & RCAR_USB3_DL_CTRL_FW_SET_DATA0) == 0)
> > > > -				break;
> > > > -			udelay(1);
> > > > -		}
> > > > -		if (time == timeout) {
> > > > -			retval = -ETIMEDOUT;
> > > > +		retval = readl_poll_timeout_atomic(regs + RCAR_USB3_DL_CTRL,
> > > > +				val, !(val & RCAR_USB3_DL_CTRL_FW_SET_DATA0),
> > > > +				1, 10000);
> > > > +		if (retval < 0)
How about free firmware and return error number here ? instead of break

> > > >  			break;
> > > > -		}
> > > >  	}
> > > >
> > > >  	temp = readl(regs + RCAR_USB3_DL_CTRL);
> > > >  	temp &= ~RCAR_USB3_DL_CTRL_ENABLE;
> > > >  	writel(temp, regs + RCAR_USB3_DL_CTRL);
> > > >
> > > > -	for (time = 0; time < timeout; time++) {
> > > > -		val = readl(regs + RCAR_USB3_DL_CTRL);
> > > > -		if (val & RCAR_USB3_DL_CTRL_FW_SUCCESS) {
> > > > -			retval = 0;
> > > > -			break;
> > > > -		}
> > > > -		udelay(1);
> > > > -	}
> > > > -	if (time == timeout)
> > > > -		retval = -ETIMEDOUT;
> > > > +	retval = readl_poll_timeout_atomic((regs + RCAR_USB3_DL_CTRL),
> > > > +			val, (val & RCAR_USB3_DL_CTRL_FW_SUCCESS), 1, 10000);
> > >
> > > Directly assigning to retval at this point will clobber a previous
> > > -ETIMEDOUT error.
> > >
> > > In other words if there is a timeout waiting for FW_SET_DATA0, but not for
> > > DW_SUCCESS, then we will return the wrong return value.
> 
> Thank you for your comment! I didn't realized this.
> 
> > Yes, agree with you, but seems I keep its original logic unchanged.
> > Hi Yoshihiro,
> > 
> >   What do think about Daniel's suggestion? should I fix it up?
> 
> I think you should fix it up like below:
> 
> if (readl_poll_timeout_atomic(regs + RCAR_USB3_DL_CTRL,
> 		val, val & RCAR_USB3_DL_CTRL_FW_SUCCESS, 1, 10000) < 0)
> 	retval = -ETIMEOUT;	/* Overwrite retval if timeout occurred */

readl_poll_timeout_atomic() only return -ETIMEOUT error number, so this
likes what I did, doesn't fix it.

> 
> Otherwise, the xhci_rcar_download_firmware() cannot return -ETIMEDOUT if
> timeout happened on the previous poll [1].
> 
> [1]
> +		retval = readl_poll_timeout_atomic(regs + RCAR_USB3_DL_CTRL,
> +				val, !(val & RCAR_USB3_DL_CTRL_FW_SET_DATA0),
> +				1, 10000);
> 
> Best regards,
> Yoshihiro Shimoda
> 

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RE: [PATCH RESEND v3 04/11] usb: xhci-rcar: convert to readl_poll_timeout_atomic()

[Yoshihiro Shimoda]

Hi Chunfeng,

> From: Chunfeng Yun, Sent: Friday, September 11, 2020 1:13 PM
> 
> On Fri, 2020-09-11 at 03:13 +0000, Yoshihiro Shimoda wrote:
> > Hi Daniel, Chunfeng,
> >
> > > From: Chunfeng Yun, Sent: Friday, September 11, 2020 11:33 AM
> > >
> > > On Thu, 2020-09-10 at 14:12 +0100, Daniel Thompson wrote:
> > > > On Thu, Sep 10, 2020 at 04:21:45PM +0800, Chunfeng Yun wrote:
> > > > > Use readl_poll_timeout_atomic() to simplify code
> > > > >
> > > > > Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
> > > > > Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> > > > > Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
> > > > > ---
> > > > > v2~v3: no changes
> > > > > ---
> > > > >  drivers/usb/host/xhci-rcar.c | 43 ++++++++++++-------------------------------
> > > > >  1 file changed, 12 insertions(+), 31 deletions(-)
> > > > >
> > > > > diff --git a/drivers/usb/host/xhci-rcar.c b/drivers/usb/host/xhci-rcar.c
> > > > > index c1025d3..74f836f 100644
> > > > > --- a/drivers/usb/host/xhci-rcar.c
> > > > > +++ b/drivers/usb/host/xhci-rcar.c
> > > > > @@ -6,6 +6,7 @@
> > > > >   */
> > > > >
> > > > >  #include <linux/firmware.h>
> > > > > +#include <linux/iopoll.h>
> > > > >  #include <linux/module.h>
> > > > >  #include <linux/platform_device.h>
> > > > >  #include <linux/of.h>
> > > > > @@ -127,8 +128,7 @@ static int xhci_rcar_download_firmware(struct usb_hcd *hcd)
> > > > >  	void __iomem *regs = hcd->regs;
> > > > >  	struct xhci_plat_priv *priv = hcd_to_xhci_priv(hcd);
> > > > >  	const struct firmware *fw;
> > > > > -	int retval, index, j, time;
> > > > > -	int timeout = 10000;
> > > > > +	int retval, index, j;
> > > > >  	u32 data, val, temp;
> > > > >  	u32 quirks = 0;
> > > > >  	const struct soc_device_attribute *attr;
> > > > > @@ -166,32 +166,19 @@ static int xhci_rcar_download_firmware(struct usb_hcd *hcd)
> > > > >  		temp |= RCAR_USB3_DL_CTRL_FW_SET_DATA0;
> > > > >  		writel(temp, regs + RCAR_USB3_DL_CTRL);
> > > > >
> > > > > -		for (time = 0; time < timeout; time++) {
> > > > > -			val = readl(regs + RCAR_USB3_DL_CTRL);
> > > > > -			if ((val & RCAR_USB3_DL_CTRL_FW_SET_DATA0) == 0)
> > > > > -				break;
> > > > > -			udelay(1);
> > > > > -		}
> > > > > -		if (time == timeout) {
> > > > > -			retval = -ETIMEDOUT;
> > > > > +		retval = readl_poll_timeout_atomic(regs + RCAR_USB3_DL_CTRL,
> > > > > +				val, !(val & RCAR_USB3_DL_CTRL_FW_SET_DATA0),
> > > > > +				1, 10000);
> > > > > +		if (retval < 0)
> How about free firmware and return error number here ? instead of break

I think clearing CTRL_ENABLE code below is needed.
And, I think this patch should not change a lot of things...

> > > > >  			break;
> > > > > -		}
> > > > >  	}
> > > > >
> > > > >  	temp = readl(regs + RCAR_USB3_DL_CTRL);
> > > > >  	temp &= ~RCAR_USB3_DL_CTRL_ENABLE;
> > > > >  	writel(temp, regs + RCAR_USB3_DL_CTRL);
> > > > >
> > > > > -	for (time = 0; time < timeout; time++) {
> > > > > -		val = readl(regs + RCAR_USB3_DL_CTRL);
> > > > > -		if (val & RCAR_USB3_DL_CTRL_FW_SUCCESS) {
> > > > > -			retval = 0;
> > > > > -			break;
> > > > > -		}
> > > > > -		udelay(1);
> > > > > -	}
> > > > > -	if (time == timeout)
> > > > > -		retval = -ETIMEDOUT;
> > > > > +	retval = readl_poll_timeout_atomic((regs + RCAR_USB3_DL_CTRL),
> > > > > +			val, (val & RCAR_USB3_DL_CTRL_FW_SUCCESS), 1, 10000);
> > > >
> > > > Directly assigning to retval at this point will clobber a previous
> > > > -ETIMEDOUT error.
> > > >
> > > > In other words if there is a timeout waiting for FW_SET_DATA0, but not for
> > > > DW_SUCCESS, then we will return the wrong return value.
> >
> > Thank you for your comment! I didn't realized this.
> >
> > > Yes, agree with you, but seems I keep its original logic unchanged.
> > > Hi Yoshihiro,
> > >
> > >   What do think about Daniel's suggestion? should I fix it up?
> >
> > I think you should fix it up like below:
> >
> > if (readl_poll_timeout_atomic(regs + RCAR_USB3_DL_CTRL,
> > 		val, val & RCAR_USB3_DL_CTRL_FW_SUCCESS, 1, 10000) < 0)
> > 	retval = -ETIMEOUT;	/* Overwrite retval if timeout occurred */
> 
> readl_poll_timeout_atomic() only return -ETIMEOUT error number, so this
> likes what I did, doesn't fix it.

readl_poll_timeout_atomic() returns 0 if timeout doesn't happen.
So, when my suggestion code runs, the retval is not overwritten if
the readl_poll_timeout_atomic(regs + RCAR_USB3_DL_CTRL...) returns 0.

Best regards,
Yoshihiro Shimoda

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Re: [PATCH RESEND v3 04/11] usb: xhci-rcar: convert to readl_poll_timeout_atomic()

[Daniel Thompson]

On Fri, Sep 11, 2020 at 10:33:21AM +0800, Chunfeng Yun wrote:
> On Thu, 2020-09-10 at 14:12 +0100, Daniel Thompson wrote:
> > On Thu, Sep 10, 2020 at 04:21:45PM +0800, Chunfeng Yun wrote:
> > > Use readl_poll_timeout_atomic() to simplify code
> > > 
> > > Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
> > > Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> > > Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
> > > ---
> > > v2~v3: no changes
> > > ---
> > >  drivers/usb/host/xhci-rcar.c | 43 ++++++++++++-------------------------------
> > >  1 file changed, 12 insertions(+), 31 deletions(-)
> > > 
> > > diff --git a/drivers/usb/host/xhci-rcar.c b/drivers/usb/host/xhci-rcar.c
> > > index c1025d3..74f836f 100644
> > > --- a/drivers/usb/host/xhci-rcar.c
> > > +++ b/drivers/usb/host/xhci-rcar.c
> > > @@ -6,6 +6,7 @@
> > >   */
> > >  
> > >  #include <linux/firmware.h>
> > > +#include <linux/iopoll.h>
> > >  #include <linux/module.h>
> > >  #include <linux/platform_device.h>
> > >  #include <linux/of.h>
> > > @@ -127,8 +128,7 @@ static int xhci_rcar_download_firmware(struct usb_hcd *hcd)
> > >  	void __iomem *regs = hcd->regs;
> > >  	struct xhci_plat_priv *priv = hcd_to_xhci_priv(hcd);
> > >  	const struct firmware *fw;
> > > -	int retval, index, j, time;
> > > -	int timeout = 10000;
> > > +	int retval, index, j;
> > >  	u32 data, val, temp;
> > >  	u32 quirks = 0;
> > >  	const struct soc_device_attribute *attr;
> > > @@ -166,32 +166,19 @@ static int xhci_rcar_download_firmware(struct usb_hcd *hcd)
> > >  		temp |= RCAR_USB3_DL_CTRL_FW_SET_DATA0;
> > >  		writel(temp, regs + RCAR_USB3_DL_CTRL);
> > >  
> > > -		for (time = 0; time < timeout; time++) {
> > > -			val = readl(regs + RCAR_USB3_DL_CTRL);
> > > -			if ((val & RCAR_USB3_DL_CTRL_FW_SET_DATA0) == 0)
> > > -				break;
> > > -			udelay(1);
> > > -		}
> > > -		if (time == timeout) {
> > > -			retval = -ETIMEDOUT;
> > > +		retval = readl_poll_timeout_atomic(regs + RCAR_USB3_DL_CTRL,
> > > +				val, !(val & RCAR_USB3_DL_CTRL_FW_SET_DATA0),
> > > +				1, 10000);
> > > +		if (retval < 0)
> > >  			break;
> > > -		}
> > >  	}
> > >  
> > >  	temp = readl(regs + RCAR_USB3_DL_CTRL);
> > >  	temp &= ~RCAR_USB3_DL_CTRL_ENABLE;
> > >  	writel(temp, regs + RCAR_USB3_DL_CTRL);
> > >  
> > > -	for (time = 0; time < timeout; time++) {
> > > -		val = readl(regs + RCAR_USB3_DL_CTRL);
> > > -		if (val & RCAR_USB3_DL_CTRL_FW_SUCCESS) {
> > > -			retval = 0;
> > > -			break;
> > > -		}
> > > -		udelay(1);
> > > -	}
> > > -	if (time == timeout)
> > > -		retval = -ETIMEDOUT;
> > > +	retval = readl_poll_timeout_atomic((regs + RCAR_USB3_DL_CTRL),
> > > +			val, (val & RCAR_USB3_DL_CTRL_FW_SUCCESS), 1, 10000);
> > 
> > Directly assigning to retval at this point will clobber a previous
> > -ETIMEDOUT error.
> > 
> > In other words if there is a timeout waiting for FW_SET_DATA0, but not for
> > DW_SUCCESS, then we will return the wrong return value.
>
> Yes, agree with you, but seems I keep its original logic unchanged.

I disagree.

Your patch does not preserve the original logic. Your patch explicitly
sets retval to zero if the second loop succeeds. The original code does
not do this. As a result there is a change of return code for one of the
error paths.


Daniel.

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Re: [PATCH RESEND v3 04/11] usb: xhci-rcar: convert to readl_poll_timeout_atomic()

[Chunfeng Yun]

On Fri, 2020-09-11 at 09:34 +0100, Daniel Thompson wrote:
> On Fri, Sep 11, 2020 at 10:33:21AM +0800, Chunfeng Yun wrote:
> > On Thu, 2020-09-10 at 14:12 +0100, Daniel Thompson wrote:
> > > On Thu, Sep 10, 2020 at 04:21:45PM +0800, Chunfeng Yun wrote:
> > > > Use readl_poll_timeout_atomic() to simplify code
> > > > 
> > > > Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
> > > > Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> > > > Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
> > > > ---
> > > > v2~v3: no changes
> > > > ---
> > > >  drivers/usb/host/xhci-rcar.c | 43 ++++++++++++-------------------------------
> > > >  1 file changed, 12 insertions(+), 31 deletions(-)
> > > > 
> > > > diff --git a/drivers/usb/host/xhci-rcar.c b/drivers/usb/host/xhci-rcar.c
> > > > index c1025d3..74f836f 100644
> > > > --- a/drivers/usb/host/xhci-rcar.c
> > > > +++ b/drivers/usb/host/xhci-rcar.c
> > > > @@ -6,6 +6,7 @@
> > > >   */
> > > >  
> > > >  #include <linux/firmware.h>
> > > > +#include <linux/iopoll.h>
> > > >  #include <linux/module.h>
> > > >  #include <linux/platform_device.h>
> > > >  #include <linux/of.h>
> > > > @@ -127,8 +128,7 @@ static int xhci_rcar_download_firmware(struct usb_hcd *hcd)
> > > >  	void __iomem *regs = hcd->regs;
> > > >  	struct xhci_plat_priv *priv = hcd_to_xhci_priv(hcd);
> > > >  	const struct firmware *fw;
> > > > -	int retval, index, j, time;
> > > > -	int timeout = 10000;
> > > > +	int retval, index, j;
> > > >  	u32 data, val, temp;
> > > >  	u32 quirks = 0;
> > > >  	const struct soc_device_attribute *attr;
> > > > @@ -166,32 +166,19 @@ static int xhci_rcar_download_firmware(struct usb_hcd *hcd)
> > > >  		temp |= RCAR_USB3_DL_CTRL_FW_SET_DATA0;
> > > >  		writel(temp, regs + RCAR_USB3_DL_CTRL);
> > > >  
> > > > -		for (time = 0; time < timeout; time++) {
> > > > -			val = readl(regs + RCAR_USB3_DL_CTRL);
> > > > -			if ((val & RCAR_USB3_DL_CTRL_FW_SET_DATA0) == 0)
> > > > -				break;
> > > > -			udelay(1);
> > > > -		}
> > > > -		if (time == timeout) {
> > > > -			retval = -ETIMEDOUT;
> > > > +		retval = readl_poll_timeout_atomic(regs + RCAR_USB3_DL_CTRL,
> > > > +				val, !(val & RCAR_USB3_DL_CTRL_FW_SET_DATA0),
> > > > +				1, 10000);
> > > > +		if (retval < 0)
> > > >  			break;
> > > > -		}
> > > >  	}
> > > >  
> > > >  	temp = readl(regs + RCAR_USB3_DL_CTRL);
> > > >  	temp &= ~RCAR_USB3_DL_CTRL_ENABLE;
> > > >  	writel(temp, regs + RCAR_USB3_DL_CTRL);
> > > >  
> > > > -	for (time = 0; time < timeout; time++) {
> > > > -		val = readl(regs + RCAR_USB3_DL_CTRL);
> > > > -		if (val & RCAR_USB3_DL_CTRL_FW_SUCCESS) {
> > > > -			retval = 0;
Here will set it 0 too

> > > > -			break;
> > > > -		}
> > > > -		udelay(1);
> > > > -	}
> > > > -	if (time == timeout)
> > > > -		retval = -ETIMEDOUT;
> > > > +	retval = readl_poll_timeout_atomic((regs + RCAR_USB3_DL_CTRL),
> > > > +			val, (val & RCAR_USB3_DL_CTRL_FW_SUCCESS), 1, 10000);
> > > 
> > > Directly assigning to retval at this point will clobber a previous
> > > -ETIMEDOUT error.
> > > 
> > > In other words if there is a timeout waiting for FW_SET_DATA0, but not for
> > > DW_SUCCESS, then we will return the wrong return value.
> >
> > Yes, agree with you, but seems I keep its original logic unchanged.
> 
> I disagree.
> 
> Your patch does not preserve the original logic. Your patch explicitly
> sets retval to zero if the second loop succeeds. The original code does
> not do this. As a result there is a change of return code for one of the
> error paths.
> 
> 
> Daniel.

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Re: [PATCH RESEND v3 04/11] usb: xhci-rcar: convert to readl_poll_timeout_atomic()

[Daniel Thompson]

On Fri, Sep 11, 2020 at 05:27:22PM +0800, Chunfeng Yun wrote:
> On Fri, 2020-09-11 at 09:34 +0100, Daniel Thompson wrote:
> > On Fri, Sep 11, 2020 at 10:33:21AM +0800, Chunfeng Yun wrote:
> > > On Thu, 2020-09-10 at 14:12 +0100, Daniel Thompson wrote:
> > > > On Thu, Sep 10, 2020 at 04:21:45PM +0800, Chunfeng Yun wrote:
> > > > > Use readl_poll_timeout_atomic() to simplify code
> > > > > 
> > > > > Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
> > > > > Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> > > > > Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
> > > > > ---
> > > > > v2~v3: no changes
> > > > > ---
> > > > >  drivers/usb/host/xhci-rcar.c | 43 ++++++++++++-------------------------------
> > > > >  1 file changed, 12 insertions(+), 31 deletions(-)
> > > > > 
> > > > > diff --git a/drivers/usb/host/xhci-rcar.c b/drivers/usb/host/xhci-rcar.c
> > > > > index c1025d3..74f836f 100644
> > > > > --- a/drivers/usb/host/xhci-rcar.c
> > > > > +++ b/drivers/usb/host/xhci-rcar.c
> > > > > @@ -6,6 +6,7 @@
> > > > >   */
> > > > >  
> > > > >  #include <linux/firmware.h>
> > > > > +#include <linux/iopoll.h>
> > > > >  #include <linux/module.h>
> > > > >  #include <linux/platform_device.h>
> > > > >  #include <linux/of.h>
> > > > > @@ -127,8 +128,7 @@ static int xhci_rcar_download_firmware(struct usb_hcd *hcd)
> > > > >  	void __iomem *regs = hcd->regs;
> > > > >  	struct xhci_plat_priv *priv = hcd_to_xhci_priv(hcd);
> > > > >  	const struct firmware *fw;
> > > > > -	int retval, index, j, time;
> > > > > -	int timeout = 10000;
> > > > > +	int retval, index, j;
> > > > >  	u32 data, val, temp;
> > > > >  	u32 quirks = 0;
> > > > >  	const struct soc_device_attribute *attr;
> > > > > @@ -166,32 +166,19 @@ static int xhci_rcar_download_firmware(struct usb_hcd *hcd)
> > > > >  		temp |= RCAR_USB3_DL_CTRL_FW_SET_DATA0;
> > > > >  		writel(temp, regs + RCAR_USB3_DL_CTRL);
> > > > >  
> > > > > -		for (time = 0; time < timeout; time++) {
> > > > > -			val = readl(regs + RCAR_USB3_DL_CTRL);
> > > > > -			if ((val & RCAR_USB3_DL_CTRL_FW_SET_DATA0) == 0)
> > > > > -				break;
> > > > > -			udelay(1);
> > > > > -		}
> > > > > -		if (time == timeout) {
> > > > > -			retval = -ETIMEDOUT;
> > > > > +		retval = readl_poll_timeout_atomic(regs + RCAR_USB3_DL_CTRL,
> > > > > +				val, !(val & RCAR_USB3_DL_CTRL_FW_SET_DATA0),
> > > > > +				1, 10000);
> > > > > +		if (retval < 0)
> > > > >  			break;
> > > > > -		}
> > > > >  	}
> > > > >  
> > > > >  	temp = readl(regs + RCAR_USB3_DL_CTRL);
> > > > >  	temp &= ~RCAR_USB3_DL_CTRL_ENABLE;
> > > > >  	writel(temp, regs + RCAR_USB3_DL_CTRL);
> > > > >  
> > > > > -	for (time = 0; time < timeout; time++) {
> > > > > -		val = readl(regs + RCAR_USB3_DL_CTRL);
> > > > > -		if (val & RCAR_USB3_DL_CTRL_FW_SUCCESS) {
> > > > > -			retval = 0;
> Here will set it 0 too

Doh...

Thanks.


Daniel.


> 
> > > > > -			break;
> > > > > -		}
> > > > > -		udelay(1);
> > > > > -	}
> > > > > -	if (time == timeout)
> > > > > -		retval = -ETIMEDOUT;
> > > > > +	retval = readl_poll_timeout_atomic((regs + RCAR_USB3_DL_CTRL),
> > > > > +			val, (val & RCAR_USB3_DL_CTRL_FW_SUCCESS), 1, 10000);
> > > > 
> > > > Directly assigning to retval at this point will clobber a previous
> > > > -ETIMEDOUT error.
> > > > 
> > > > In other words if there is a timeout waiting for FW_SET_DATA0, but not for
> > > > DW_SUCCESS, then we will return the wrong return value.
> > >
> > > Yes, agree with you, but seems I keep its original logic unchanged.
> > 
> > I disagree.
> > 
> > Your patch does not preserve the original logic. Your patch explicitly
> > sets retval to zero if the second loop succeeds. The original code does
> > not do this. As a result there is a change of return code for one of the
> > error paths.
> > 
> > 
> > Daniel.
> 

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RE: [PATCH RESEND v3 04/11] usb: xhci-rcar: convert to readl_poll_timeout_atomic()

[Yoshihiro Shimoda]

Hi Chunfeng,

> From: Daniel Thompson, Sent: Friday, September 11, 2020 6:49 PM
> 
> On Fri, Sep 11, 2020 at 05:27:22PM +0800, Chunfeng Yun wrote:
> > On Fri, 2020-09-11 at 09:34 +0100, Daniel Thompson wrote:
> > > On Fri, Sep 11, 2020 at 10:33:21AM +0800, Chunfeng Yun wrote:
> > > > On Thu, 2020-09-10 at 14:12 +0100, Daniel Thompson wrote:
> > > > > On Thu, Sep 10, 2020 at 04:21:45PM +0800, Chunfeng Yun wrote:
> > > > > > Use readl_poll_timeout_atomic() to simplify code
> > > > > >
> > > > > > Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
> > > > > > Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> > > > > > Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
> > > > > > ---
> > > > > > v2~v3: no changes
> > > > > > ---
> > > > > >  drivers/usb/host/xhci-rcar.c | 43 ++++++++++++-------------------------------
> > > > > >  1 file changed, 12 insertions(+), 31 deletions(-)
> > > > > >
> > > > > > diff --git a/drivers/usb/host/xhci-rcar.c b/drivers/usb/host/xhci-rcar.c
> > > > > > index c1025d3..74f836f 100644
> > > > > > --- a/drivers/usb/host/xhci-rcar.c
> > > > > > +++ b/drivers/usb/host/xhci-rcar.c
> > > > > > @@ -6,6 +6,7 @@
> > > > > >   */
> > > > > >
> > > > > >  #include <linux/firmware.h>
> > > > > > +#include <linux/iopoll.h>
> > > > > >  #include <linux/module.h>
> > > > > >  #include <linux/platform_device.h>
> > > > > >  #include <linux/of.h>
> > > > > > @@ -127,8 +128,7 @@ static int xhci_rcar_download_firmware(struct usb_hcd *hcd)
> > > > > >  	void __iomem *regs = hcd->regs;
> > > > > >  	struct xhci_plat_priv *priv = hcd_to_xhci_priv(hcd);
> > > > > >  	const struct firmware *fw;
> > > > > > -	int retval, index, j, time;
> > > > > > -	int timeout = 10000;
> > > > > > +	int retval, index, j;
> > > > > >  	u32 data, val, temp;
> > > > > >  	u32 quirks = 0;
> > > > > >  	const struct soc_device_attribute *attr;
> > > > > > @@ -166,32 +166,19 @@ static int xhci_rcar_download_firmware(struct usb_hcd *hcd)
> > > > > >  		temp |= RCAR_USB3_DL_CTRL_FW_SET_DATA0;
> > > > > >  		writel(temp, regs + RCAR_USB3_DL_CTRL);
> > > > > >
> > > > > > -		for (time = 0; time < timeout; time++) {
> > > > > > -			val = readl(regs + RCAR_USB3_DL_CTRL);
> > > > > > -			if ((val & RCAR_USB3_DL_CTRL_FW_SET_DATA0) == 0)
> > > > > > -				break;
> > > > > > -			udelay(1);
> > > > > > -		}
> > > > > > -		if (time == timeout) {
> > > > > > -			retval = -ETIMEDOUT;
> > > > > > +		retval = readl_poll_timeout_atomic(regs + RCAR_USB3_DL_CTRL,
> > > > > > +				val, !(val & RCAR_USB3_DL_CTRL_FW_SET_DATA0),
> > > > > > +				1, 10000);
> > > > > > +		if (retval < 0)
> > > > > >  			break;
> > > > > > -		}
> > > > > >  	}
> > > > > >
> > > > > >  	temp = readl(regs + RCAR_USB3_DL_CTRL);
> > > > > >  	temp &= ~RCAR_USB3_DL_CTRL_ENABLE;
> > > > > >  	writel(temp, regs + RCAR_USB3_DL_CTRL);
> > > > > >
> > > > > > -	for (time = 0; time < timeout; time++) {
> > > > > > -		val = readl(regs + RCAR_USB3_DL_CTRL);
> > > > > > -		if (val & RCAR_USB3_DL_CTRL_FW_SUCCESS) {
> > > > > > -			retval = 0;
> > Here will set it 0 too
> 
> Doh...
> 
> Thanks.

Ah, now I also understood your patch was logically unchanged.
Thanks!

Best regards,
Yoshihiro Shimoda


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Re: [PATCH RESEND v3 04/11] usb: xhci-rcar: convert to readl_poll_timeout_atomic()

[Chunfeng Yun]

On Fri, 2020-09-11 at 04:57 +0000, Yoshihiro Shimoda wrote:
> Hi Chunfeng,
> 
> > From: Chunfeng Yun, Sent: Friday, September 11, 2020 1:13 PM
> > 
> > On Fri, 2020-09-11 at 03:13 +0000, Yoshihiro Shimoda wrote:
> > > Hi Daniel, Chunfeng,
> > >
> > > > From: Chunfeng Yun, Sent: Friday, September 11, 2020 11:33 AM
> > > >
> > > > On Thu, 2020-09-10 at 14:12 +0100, Daniel Thompson wrote:
> > > > > On Thu, Sep 10, 2020 at 04:21:45PM +0800, Chunfeng Yun wrote:
> > > > > > Use readl_poll_timeout_atomic() to simplify code
> > > > > >
> > > > > > Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
> > > > > > Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> > > > > > Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
> > > > > > ---
> > > > > > v2~v3: no changes
> > > > > > ---
> > > > > >  drivers/usb/host/xhci-rcar.c | 43 ++++++++++++-------------------------------
> > > > > >  1 file changed, 12 insertions(+), 31 deletions(-)
> > > > > >
> > > > > > diff --git a/drivers/usb/host/xhci-rcar.c b/drivers/usb/host/xhci-rcar.c
> > > > > > index c1025d3..74f836f 100644
> > > > > > --- a/drivers/usb/host/xhci-rcar.c
> > > > > > +++ b/drivers/usb/host/xhci-rcar.c
> > > > > > @@ -6,6 +6,7 @@
> > > > > >   */
> > > > > >
> > > > > >  #include <linux/firmware.h>
> > > > > > +#include <linux/iopoll.h>
> > > > > >  #include <linux/module.h>
> > > > > >  #include <linux/platform_device.h>
> > > > > >  #include <linux/of.h>
> > > > > > @@ -127,8 +128,7 @@ static int xhci_rcar_download_firmware(struct usb_hcd *hcd)
> > > > > >  	void __iomem *regs = hcd->regs;
> > > > > >  	struct xhci_plat_priv *priv = hcd_to_xhci_priv(hcd);
> > > > > >  	const struct firmware *fw;
> > > > > > -	int retval, index, j, time;
> > > > > > -	int timeout = 10000;
> > > > > > +	int retval, index, j;
> > > > > >  	u32 data, val, temp;
> > > > > >  	u32 quirks = 0;
> > > > > >  	const struct soc_device_attribute *attr;
> > > > > > @@ -166,32 +166,19 @@ static int xhci_rcar_download_firmware(struct usb_hcd *hcd)
> > > > > >  		temp |= RCAR_USB3_DL_CTRL_FW_SET_DATA0;
> > > > > >  		writel(temp, regs + RCAR_USB3_DL_CTRL);
> > > > > >
> > > > > > -		for (time = 0; time < timeout; time++) {
> > > > > > -			val = readl(regs + RCAR_USB3_DL_CTRL);
> > > > > > -			if ((val & RCAR_USB3_DL_CTRL_FW_SET_DATA0) == 0)
> > > > > > -				break;
> > > > > > -			udelay(1);
> > > > > > -		}
> > > > > > -		if (time == timeout) {
> > > > > > -			retval = -ETIMEDOUT;
> > > > > > +		retval = readl_poll_timeout_atomic(regs + RCAR_USB3_DL_CTRL,
> > > > > > +				val, !(val & RCAR_USB3_DL_CTRL_FW_SET_DATA0),
> > > > > > +				1, 10000);
> > > > > > +		if (retval < 0)
> > How about free firmware and return error number here ? instead of break
> 
> I think clearing CTRL_ENABLE code below is needed.
> And, I think this patch should not change a lot of things...
Ok, thanks

> 
> > > > > >  			break;
> > > > > > -		}
> > > > > >  	}
> > > > > >
> > > > > >  	temp = readl(regs + RCAR_USB3_DL_CTRL);
> > > > > >  	temp &= ~RCAR_USB3_DL_CTRL_ENABLE;
> > > > > >  	writel(temp, regs + RCAR_USB3_DL_CTRL);
> > > > > >
> > > > > > -	for (time = 0; time < timeout; time++) {
> > > > > > -		val = readl(regs + RCAR_USB3_DL_CTRL);
> > > > > > -		if (val & RCAR_USB3_DL_CTRL_FW_SUCCESS) {
> > > > > > -			retval = 0;
> > > > > > -			break;
> > > > > > -		}
> > > > > > -		udelay(1);
> > > > > > -	}
> > > > > > -	if (time == timeout)
> > > > > > -		retval = -ETIMEDOUT;
> > > > > > +	retval = readl_poll_timeout_atomic((regs + RCAR_USB3_DL_CTRL),
> > > > > > +			val, (val & RCAR_USB3_DL_CTRL_FW_SUCCESS), 1, 10000);
> > > > >
> > > > > Directly assigning to retval at this point will clobber a previous
> > > > > -ETIMEDOUT error.
> > > > >
> > > > > In other words if there is a timeout waiting for FW_SET_DATA0, but not for
> > > > > DW_SUCCESS, then we will return the wrong return value.
> > >
> > > Thank you for your comment! I didn't realized this.
> > >
> > > > Yes, agree with you, but seems I keep its original logic unchanged.
> > > > Hi Yoshihiro,
> > > >
> > > >   What do think about Daniel's suggestion? should I fix it up?
> > >
> > > I think you should fix it up like below:
> > >
> > > if (readl_poll_timeout_atomic(regs + RCAR_USB3_DL_CTRL,
> > > 		val, val & RCAR_USB3_DL_CTRL_FW_SUCCESS, 1, 10000) < 0)
> > > 	retval = -ETIMEOUT;	/* Overwrite retval if timeout occurred */
> > 
> > readl_poll_timeout_atomic() only return -ETIMEOUT error number, so this
> > likes what I did, doesn't fix it.
> 
> readl_poll_timeout_atomic() returns 0 if timeout doesn't happen.
> So, when my suggestion code runs, the retval is not overwritten if
> the readl_poll_timeout_atomic(regs + RCAR_USB3_DL_CTRL...) returns 0.
> 
> Best regards,
> Yoshihiro Shimoda
> 

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