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-rw-r--r--drivers/i2c/busses/i2c-tegra.c27
1 files changed, 15 insertions, 12 deletions
diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index 4c4d17ddc96b..a795b4e278b1 100644
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -996,14 +996,13 @@ tegra_i2c_poll_completion_timeout(struct tegra_i2c_dev *i2c_dev,
 	do {
 		u32 status = i2c_readl(i2c_dev, I2C_INT_STATUS);
 
-		if (status) {
+		if (status)
 			tegra_i2c_isr(i2c_dev->irq, i2c_dev);
 
-			if (completion_done(complete)) {
-				s64 delta = ktime_ms_delta(ktimeout, ktime);
+		if (completion_done(complete)) {
+			s64 delta = ktime_ms_delta(ktimeout, ktime);
 
-				return msecs_to_jiffies(delta) ?: 1;
-			}
+			return msecs_to_jiffies(delta) ?: 1;
 		}
 
 		ktime = ktime_get();
@@ -1030,14 +1029,18 @@ tegra_i2c_wait_completion_timeout(struct tegra_i2c_dev *i2c_dev,
 		disable_irq(i2c_dev->irq);
 
 		/*
-		 * There is a chance that completion may happen after IRQ
-		 * synchronization, which is done by disable_irq().
+		 * Under some rare circumstances (like running KASAN +
+		 * NFS root) CPU, which handles interrupt, may stuck in
+		 * uninterruptible state for a significant time.  In this
+		 * case we will get timeout if I2C transfer is running on
+		 * a sibling CPU, despite of IRQ being raised.
+		 *
+		 * In order to handle this rare condition, the IRQ status
+		 * needs to be checked after timeout.
 		 */
-		if (ret == 0 && completion_done(complete)) {
-			dev_warn(i2c_dev->dev,
-				 "completion done after timeout\n");
-			ret = 1;
-		}
+		if (ret == 0)
+			ret = tegra_i2c_poll_completion_timeout(i2c_dev,
+								complete, 0);
 	}
 
 	return ret;