1 files changed, 46 insertions, 9 deletions

diff --git a/drivers/i2c/busses/i2c-octeon.c b/drivers/i2c/busses/i2c-octeon.c
index 4fc471ce173e..cb418140cbbe 100644
--- a/drivers/i2c/busses/i2c-octeon.c
+++ b/drivers/i2c/busses/i2c-octeon.c
@@ -109,6 +109,8 @@
 #define TWSI_INT_SDA		BIT_ULL(10)
 #define TWSI_INT_SCL		BIT_ULL(11)
 
+#define I2C_OCTEON_EVENT_WAIT 80 /* microseconds */
+
 struct octeon_i2c {
 	wait_queue_head_t queue;
 	struct i2c_adapter adap;
@@ -339,11 +341,29 @@ static irqreturn_t octeon_i2c_hlc_isr78(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
-static int octeon_i2c_test_iflg(struct octeon_i2c *i2c)
+static bool octeon_i2c_test_iflg(struct octeon_i2c *i2c)
 {
 	return (octeon_i2c_ctl_read(i2c) & TWSI_CTL_IFLG);
 }
 
+static bool octeon_i2c_test_ready(struct octeon_i2c *i2c, bool *first)
+{
+	if (octeon_i2c_test_iflg(i2c))
+		return true;
+
+	if (*first) {
+		*first = false;
+		return false;
+	}
+
+	/*
+	 * IRQ has signaled an event but IFLG hasn't changed.
+	 * Sleep and retry once.
+	 */
+	usleep_range(I2C_OCTEON_EVENT_WAIT, 2 * I2C_OCTEON_EVENT_WAIT);
+	return octeon_i2c_test_iflg(i2c);
+}
+
 /**
  * octeon_i2c_wait - wait for the IFLG to be set
  * @i2c: The struct octeon_i2c
@@ -353,15 +373,14 @@ static int octeon_i2c_test_iflg(struct octeon_i2c *i2c)
 static int octeon_i2c_wait(struct octeon_i2c *i2c)
 {
 	long time_left;
+	bool first = 1;
 
 	i2c->int_enable(i2c);
-	time_left = wait_event_timeout(i2c->queue, octeon_i2c_test_iflg(i2c),
+	time_left = wait_event_timeout(i2c->queue, octeon_i2c_test_ready(i2c, &first),
 				       i2c->adap.timeout);
 	i2c->int_disable(i2c);
-	if (!time_left) {
-		dev_dbg(i2c->dev, "%s: timeout\n", __func__);
+	if (!time_left)
 		return -ETIMEDOUT;
-	}
 
 	return 0;
 }
@@ -427,11 +446,28 @@ static int octeon_i2c_check_status(struct octeon_i2c *i2c, int final_read)
 	}
 }
 
-static bool octeon_i2c_hlc_test_ready(struct octeon_i2c *i2c)
+static bool octeon_i2c_hlc_test_valid(struct octeon_i2c *i2c)
+{
+	return (__raw_readq(i2c->twsi_base + SW_TWSI) & SW_TWSI_V) == 0;
+}
+
+static bool octeon_i2c_hlc_test_ready(struct octeon_i2c *i2c, bool *first)
 {
-	u64 val = __raw_readq(i2c->twsi_base + SW_TWSI);
+	/* check if valid bit is cleared */
+	if (octeon_i2c_hlc_test_valid(i2c))
+		return true;
 
-	return (val & SW_TWSI_V) == 0;
+	if (*first) {
+		*first = false;
+		return false;
+	}
+
+	/*
+	 * IRQ has signaled an event but valid bit isn't cleared.
+	 * Sleep and retry once.
+	 */
+	usleep_range(I2C_OCTEON_EVENT_WAIT, 2 * I2C_OCTEON_EVENT_WAIT);
+	return octeon_i2c_hlc_test_valid(i2c);
 }
 
 static void octeon_i2c_hlc_int_enable(struct octeon_i2c *i2c)
@@ -453,11 +489,12 @@ static void octeon_i2c_hlc_int_clear(struct octeon_i2c *i2c)
  */
 static int octeon_i2c_hlc_wait(struct octeon_i2c *i2c)
 {
+	bool first = 1;
 	int time_left;
 
 	i2c->hlc_int_enable(i2c);
 	time_left = wait_event_timeout(i2c->queue,
-				       octeon_i2c_hlc_test_ready(i2c),
+				       octeon_i2c_hlc_test_ready(i2c, &first),
 				       i2c->adap.timeout);
 	i2c->hlc_int_disable(i2c);
 	if (!time_left) {