From 2be6a2d4eaa4db01d3afbd5e9d6fd15494a87f2f Mon Sep 17 00:00:00 2001
From: Bo Jiao <Bo.Jiao@mediatek.com>
Date: Fri, 17 Jun 2022 11:23:57 +0800
Subject: [PATCH 2/8] 9991-add-read-poll-timeout-function-for-kernel5.4

---
 include/linux/iopoll.h | 30 +++++++++++++++++++++++++++---
 1 file changed, 27 insertions(+), 3 deletions(-)
 mode change 100644 => 100755 include/linux/iopoll.h

diff --git a/include/linux/iopoll.h b/include/linux/iopoll.h
old mode 100644
new mode 100755
index 35e15dfd4..d96087008
--- a/include/linux/iopoll.h
+++ b/include/linux/iopoll.h
@@ -31,19 +31,22 @@
  * 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 +55,27 @@
 	(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)
-- 
2.18.0