target/linux/generic/backport-5.4/999-2700-v5.7-iopoll-introduce-read_poll_timeout-macro.patch

From bc97a676615bd0ec66bb2a2a42c939455bf5bed6 Mon Sep 17 00:00:00 2001
From: Sam Shih <sam.shih@mediatek.com>
Date: Fri, 2 Jun 2023 13:06:27 +0800
Subject: [PATCH] 
 [networking][999-2700-v5.7-iopoll-introduce-read_poll_timeout-macro.patch]

---
 drivers/net/phy/phy_device.c | 16 +++++----------
 include/linux/iopoll.h       | 40 +++++++++++++++++++++++++++++-------
 include/linux/phy.h          | 27 ++++++++++++++++++++++++
 3 files changed, 65 insertions(+), 18 deletions(-)

diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 76a68bb02..0349801df 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -1056,18 +1056,12 @@ EXPORT_SYMBOL(phy_disconnect);
 static int phy_poll_reset(struct phy_device *phydev)
 {
 	/* Poll until the reset bit clears (50ms per retry == 0.6 sec) */
-	unsigned int retries = 12;
-	int ret;
-
-	do {
-		msleep(50);
-		ret = phy_read(phydev, MII_BMCR);
-		if (ret < 0)
-			return ret;
-	} while (ret & BMCR_RESET && --retries);
-	if (ret & BMCR_RESET)
-		return -ETIMEDOUT;
+	int ret, val;
 
+	ret = phy_read_poll_timeout(phydev, MII_BMCR, val, !(val & BMCR_RESET),
+				    50000, 600000, true);
+	if (ret)
+		return ret;
 	/* Some chips (smsc911x) may still need up to another 1ms after the
 	 * BMCR_RESET bit is cleared before they are usable.
 	 */
diff --git a/include/linux/iopoll.h b/include/linux/iopoll.h
index 35e15dfd4..cb20c733b 100644
--- a/include/linux/iopoll.h
+++ b/include/linux/iopoll.h
@@ -14,36 +14,41 @@
 #include <linux/io.h>
 
 /**
- * readx_poll_timeout - 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
+ * read_poll_timeout - Periodically poll an address until a condition is
+ *			met or a timeout occurs
+ * @op: accessor function (takes @args as its arguments)
  * @val: Variable to read the value into
  * @cond: Break condition (usually involving @val)
  * @sleep_us: Maximum time to sleep between reads in us (0
  *            tight-loops).  Should be less than ~20ms since usleep_range
  *            is used (see Documentation/timers/timers-howto.rst).
  * @timeout_us: Timeout in us, 0 means never timeout
+ * @sleep_before_read: if it is true, sleep @sleep_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 @addr is stored in @val. Must not
+ * case, the last read value at @args is stored in @val. Must not
  * be called from atomic context if sleep_us or timeout_us are used.
  *
  * When available, you'll probably want to use one of the specialized
  * macros defined below rather than this macro directly.
  */
-#define readx_poll_timeout(op, addr, val, cond, sleep_us, timeout_us)	\
+#define read_poll_timeout(op, val, cond, sleep_us, timeout_us, \
+				sleep_before_read, args...) \
 ({ \
 	u64 __timeout_us = (timeout_us); \
 	unsigned long __sleep_us = (sleep_us); \
 	ktime_t __timeout = ktime_add_us(ktime_get(), __timeout_us); \
 	might_sleep_if((__sleep_us) != 0); \
+	if (sleep_before_read && __sleep_us) \
+		usleep_range((__sleep_us >> 2) + 1, __sleep_us); \
 	for (;;) { \
-		(val) = op(addr); \
+		(val) = op(args); \
 		if (cond) \
 			break; \
 		if (__timeout_us && \
 		    ktime_compare(ktime_get(), __timeout) > 0) { \
-			(val) = op(addr); \
+			(val) = op(args); \
 			break; \
 		} \
 		if (__sleep_us) \
@@ -52,6 +57,27 @@
 	(cond) ? 0 : -ETIMEDOUT; \
 })
 
+/**
+ * readx_poll_timeout - 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
+ * @val: Variable to read the value into
+ * @cond: Break condition (usually involving @val)
+ * @sleep_us: Maximum time to sleep between reads in us (0
+ *            tight-loops).  Should be less than ~20ms since usleep_range
+ *            is used (see Documentation/timers/timers-howto.rst).
+ * @timeout_us: Timeout in us, 0 means never timeout
+ *
+ * Returns 0 on success and -ETIMEDOUT upon a timeout. In either
+ * case, the last read value at @addr is stored in @val. Must not
+ * be called from atomic context if sleep_us or timeout_us are used.
+ *
+ * When available, you'll probably want to use one of the specialized
+ * macros defined below rather than this macro directly.
+ */
+#define readx_poll_timeout(op, addr, val, cond, sleep_us, timeout_us)	\
+	read_poll_timeout(op, val, cond, sleep_us, timeout_us, false, addr)
+
 /**
  * readx_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)
diff --git a/include/linux/phy.h b/include/linux/phy.h
index a1070d60e..107dcbea4 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -21,6 +21,7 @@
 #include <linux/timer.h>
 #include <linux/workqueue.h>
 #include <linux/mod_devicetable.h>
+#include <linux/iopoll.h>
 
 #include <linux/atomic.h>
 
@@ -714,6 +715,19 @@ static inline int phy_read(struct phy_device *phydev, u32 regnum)
 	return mdiobus_read(phydev->mdio.bus, phydev->mdio.addr, regnum);
 }
 
+#define phy_read_poll_timeout(phydev, regnum, val, cond, sleep_us, \
+				timeout_us, sleep_before_read) \
+({ \
+	int __ret = read_poll_timeout(phy_read, val, (cond) || val < 0, \
+		sleep_us, timeout_us, sleep_before_read, phydev, regnum); \
+	if (val <  0) \
+		__ret = val; \
+	if (__ret) \
+		phydev_err(phydev, "%s failed: %d\n", __func__, __ret); \
+	__ret; \
+})
+
+
 /**
  * __phy_read - convenience function for reading a given PHY register
  * @phydev: the phy_device struct
@@ -766,6 +780,19 @@ static inline int __phy_write(struct phy_device *phydev, u32 regnum, u16 val)
  */
 int phy_read_mmd(struct phy_device *phydev, int devad, u32 regnum);
 
+#define phy_read_mmd_poll_timeout(phydev, devaddr, regnum, val, cond, \
+				  sleep_us, timeout_us, sleep_before_read) \
+({ \
+	int __ret = read_poll_timeout(phy_read_mmd, val, (cond) || val < 0, \
+				  sleep_us, timeout_us, sleep_before_read, \
+				  phydev, devaddr, regnum); \
+	if (val <  0) \
+		__ret = val; \
+	if (__ret) \
+		phydev_err(phydev, "%s failed: %d\n", __func__, __ret); \
+	__ret; \
+})
+
 /**
  * __phy_read_mmd - Convenience function for reading a register
  * from an MMD on a given PHY.
-- 
2.34.1