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phy: samsung: Use readl_poll_timeout function

PATCH Superseded Anand Moon 2 participants 3 messages Jul 5, 2020 – Jul 6, 2020

Subsystems (2)
Arm Samsung Exynos Generic PHY framework

v2 of 5 Superseded Latest is v5 →

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Anand Moon

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#0 lore raw

PATCH v2 1/1 phy: samsung: Use readl_poll_timeout function

User readl_poll_timeout function instead of open
coded handling in crport_handshake function.

Fixes d8c80bb3b55b ("phy: exynos5-usbdrd: Calibrate LOS levels for exynos5420/5800")
Signed-off-by Anand Moon <[email protected]>

---
Changes v2:
--used the default timeout values.
--Added missing Fixed tags.

---
 drivers/phy/samsung/phy-exynos5-usbdrd.c | 37 +++++++++---------------
 1 file changed, 13 insertions(+), 24 deletions(-)
drivers/phy/samsung/phy-exynos5-usbdrd.c +13 -24
index e510732afb8b..c97f5fb6a9a0 100644
@@ -16,6 +16,7 @@
 #include <linux/of.h>
 #include <linux/of_address.h>
 #include <linux/of_device.h>
+#include <linux/iopoll.h>
 #include <linux/phy/phy.h>
 #include <linux/platform_device.h>
 #include <linux/mutex.h>

@@ -556,40 +557,28 @@ static int exynos5_usbdrd_phy_power_off(struct phy *phy)
 static int crport_handshake(struct exynos5_usbdrd_phy *phy_drd,
 			    u32 val, u32 cmd)
 {
-	u32 usec = 100;
+	u32 timeout_us = 100, sleep_us = 1;
 	unsigned int result;
+	int err;
 
 	writel(val | cmd, phy_drd->reg_phy + EXYNOS5_DRD_PHYREG0);
 
-	do {
-		result = readl(phy_drd->reg_phy + EXYNOS5_DRD_PHYREG1);
-		if (result & PHYREG1_CR_ACK)
-			break;
-
-		udelay(1);
-	} while (usec-- > 0);
-
-	if (!usec) {
-		dev_err(phy_drd->dev,
-			"CRPORT handshake timeout1 (0x%08x)\n", val);
+	err = readl_poll_timeout(phy_drd->reg_phy + EXYNOS5_DRD_PHYREG1,
+			result,	(result & PHYREG1_CR_ACK), sleep_us, timeout_us);
+	if (err) {
+		dev_err(phy_drd->dev, "CRPORT handshake timeout1 (0x%08x)\n", val);
 		return -ETIME;
 	}
 
-	usec = 100;
+	timeout_us = 100;
+	sleep_us = 1;
 
 	writel(val, phy_drd->reg_phy + EXYNOS5_DRD_PHYREG0);
 
-	do {
-		result = readl(phy_drd->reg_phy + EXYNOS5_DRD_PHYREG1);
-		if (!(result & PHYREG1_CR_ACK))
-			break;
-
-		udelay(1);
-	} while (usec-- > 0);
-
-	if (!usec) {
-		dev_err(phy_drd->dev,
-			"CRPORT handshake timeout2 (0x%08x)\n", val);
+	err = readl_poll_timeout(phy_drd->reg_phy + EXYNOS5_DRD_PHYREG1,
+			result,	!(result & PHYREG1_CR_ACK), sleep_us, timeout_us);
+	if (err) {
+		dev_err(phy_drd->dev, "CRPORT handshake timeout2 (0x%08x)\n", val);
 		return -ETIME;
 	}
Signature · 1 line
2.27.0
maintainer
#1 lore raw
Quoted 2 lines · Anand Moon

User readl_poll_timeout function instead of open
coded handling in crport_handshake function.

Your change does not replace only the "open coded handling" with readl_poll_timeout(). Your change does more - switches busy waiting with udelay to a sleeping mode. I am not sure if it is correct but definitly it should be mentioned. Otherwise how can we be sure that you checked if this is allowed in this section? Did you test everything with DEBUG_ATOMIC_SLEEP?

Quoted 24 lines
Fixes d8c80bb3b55b ("phy: exynos5-usbdrd: Calibrate LOS levels for exynos5420/5800")
Signed-off-by Anand Moon <[email protected]>

---
Changes v2:
--used the default timeout values.
--Added missing Fixed tags.

---
 drivers/phy/samsung/phy-exynos5-usbdrd.c | 37 +++++++++---------------
 1 file changed, 13 insertions(+), 24 deletions(-)
drivers/phy/samsung/phy-exynos5-usbdrd.c +1 -0
index e510732afb8b..c97f5fb6a9a0 100644
@@ -16,6 +16,7 @@
 #include <linux/of.h>
 #include <linux/of_address.h>
 #include <linux/of_device.h>
+#include <linux/iopoll.h>
 #include <linux/phy/phy.h>
 #include <linux/platform_device.h>
 #include <linux/mutex.h>

drivers/phy/samsung/phy-exynos5-usbdrd.c static int exynos5_usbdrd_phy_power_off(struct phy *phy) · line 560

Quoted 5 lines
drivers/phy/samsung/phy-exynos5-usbdrd.c +1 -1
@@ -556,40 +557,28 @@ static int exynos5_usbdrd_phy_power_off(struct phy *phy)
 static int crport_handshake(struct exynos5_usbdrd_phy *phy_drd,
 			    u32 val, u32 cmd)
 {
-	u32 usec = 100;
+	u32 timeout_us = 100, sleep_us = 1;

No need for the variables actually and their type does not match. Just use the values directly.

Quoted 16 lines
drivers/phy/samsung/phy-exynos5-usbdrd.c +1 -11
 	unsigned int result;
+	int err;
 
 	writel(val | cmd, phy_drd->reg_phy + EXYNOS5_DRD_PHYREG0);
 
-	do {
-		result = readl(phy_drd->reg_phy + EXYNOS5_DRD_PHYREG1);
-		if (result & PHYREG1_CR_ACK)
-			break;
-
-		udelay(1);
-	} while (usec-- > 0);
-
-	if (!usec) {
-		dev_err(phy_drd->dev,
-			"CRPORT handshake timeout1 (0x%08x)\n", val);

drivers/phy/samsung/phy-exynos5-usbdrd.c static int exynos5_usbdrd_phy_power_off(struct phy *phy) · line 574

Quoted 10 lines
drivers/phy/samsung/phy-exynos5-usbdrd.c +6 -1
+	err = readl_poll_timeout(phy_drd->reg_phy + EXYNOS5_DRD_PHYREG1,
+			result,	(result & PHYREG1_CR_ACK), sleep_us, timeout_us);
+	if (err) {
+		dev_err(phy_drd->dev, "CRPORT handshake timeout1 (0x%08x)\n", val);
 		return -ETIME;
 	}
 
-	usec = 100;
+	timeout_us = 100;
+	sleep_us = 1;

Why defining then again?

Best regards,
Krzysztof

Quoted 24 lines
drivers/phy/samsung/phy-exynos5-usbdrd.c +4 -11
 	writel(val, phy_drd->reg_phy + EXYNOS5_DRD_PHYREG0);
 
-	do {
-		result = readl(phy_drd->reg_phy + EXYNOS5_DRD_PHYREG1);
-		if (!(result & PHYREG1_CR_ACK))
-			break;
-
-		udelay(1);
-	} while (usec-- > 0);
-
-	if (!usec) {
-		dev_err(phy_drd->dev,
-			"CRPORT handshake timeout2 (0x%08x)\n", val);
+	err = readl_poll_timeout(phy_drd->reg_phy + EXYNOS5_DRD_PHYREG1,
+			result,	!(result & PHYREG1_CR_ACK), sleep_us, timeout_us);
+	if (err) {
+		dev_err(phy_drd->dev, "CRPORT handshake timeout2 (0x%08x)\n", val);
 		return -ETIME;
 	}
Signature · 1 line
2.27.0
author
#2 lore raw

Hi Krzysztof,

Thanks for your review comments.

Quoted 11 lines · Krzysztof Kozlowski
Quoted 2 lines · Anand Moon

User readl_poll_timeout function instead of open
coded handling in crport_handshake function.

Your change does not replace only the "open coded handling" with readl_poll_timeout(). Your change does more - switches busy waiting with udelay to a sleeping mode. I am not sure if it is correct but definitly it should be mentioned. Otherwise how can we be sure that you checked if this is allowed in this section? Did you test everything with DEBUG_ATOMIC_SLEEP?

Yes this DEBUG_ATOMIC_SLEEP is enabled in exynos_defconfig.

Quoted 1 line

Ok how about the below commit message.

Instead of a busy waiting loop while loop using udelay use readl_poll_timeout function to check the condition is met or timeout occurs in crport_handshake function.

Quoted 24 lines
Quoted 24 lines
Fixes d8c80bb3b55b ("phy: exynos5-usbdrd: Calibrate LOS levels for exynos5420/5800")
Signed-off-by Anand Moon <[email protected]>

---
Changes v2:
--used the default timeout values.
--Added missing Fixed tags.

---
 drivers/phy/samsung/phy-exynos5-usbdrd.c | 37 +++++++++---------------
 1 file changed, 13 insertions(+), 24 deletions(-)
drivers/phy/samsung/phy-exynos5-usbdrd.c +1 -0
index e510732afb8b..c97f5fb6a9a0 100644
@@ -16,6 +16,7 @@
 #include <linux/of.h>
 #include <linux/of_address.h>
 #include <linux/of_device.h>
+#include <linux/iopoll.h>
 #include <linux/phy/phy.h>
 #include <linux/platform_device.h>
 #include <linux/mutex.h>

@@ -556,40 +557,28 @@ static int exynos5_usbdrd_phy_power_off(struct phy *phy)
Quoted 8 lines

drivers/phy/samsung/phy-exynos5-usbdrd.c static int exynos5_usbdrd_phy_power_off(struct phy *phy) · line 560

Quoted 5 lines
drivers/phy/samsung/phy-exynos5-usbdrd.c +1 -1
 static int crport_handshake(struct exynos5_usbdrd_phy *phy_drd,
                          u32 val, u32 cmd)
 {
-     u32 usec = 100;
+     u32 timeout_us = 100, sleep_us = 1;

No need for the variables actually and their type does not match. Just use the values directly.

Ok thanks

Quoted 24 lines
Quoted 24 lines
drivers/phy/samsung/phy-exynos5-usbdrd.c +5 -11
      unsigned int result;
+     int err;
 
      writel(val | cmd, phy_drd->reg_phy + EXYNOS5_DRD_PHYREG0);
 
-     do {
-             result = readl(phy_drd->reg_phy + EXYNOS5_DRD_PHYREG1);
-             if (result & PHYREG1_CR_ACK)
-                     break;
-
-             udelay(1);
-     } while (usec-- > 0);
-
-     if (!usec) {
-             dev_err(phy_drd->dev,
-                     "CRPORT handshake timeout1 (0x%08x)\n", val);
+     err = readl_poll_timeout(phy_drd->reg_phy + EXYNOS5_DRD_PHYREG1,
+                     result, (result & PHYREG1_CR_ACK), sleep_us, timeout_us);
+     if (err) {
+             dev_err(phy_drd->dev, "CRPORT handshake timeout1 (0x%08x)\n", val);
              return -ETIME;
      }
Quoted 5 lines

drivers/phy/samsung/phy-exynos5-usbdrd.c static int exynos5_usbdrd_phy_power_off(struct phy *phy) · line 574

Quoted 3 lines
drivers/phy/samsung/phy-exynos5-usbdrd.c +2 -1
-     usec = 100;
+     timeout_us = 100;
+     sleep_us = 1;

Why defining then again?

I had removed this in this but last minute I added this code again.

Quoted 4 lines

Best regards,
Krzysztof

Best Regards
-Anand