From f6dd8c259ab82ca3e44a22542202e061cb23978c Mon Sep 17 00:00:00 2001 From: Chunyan Zhang Date: Mon, 14 Dec 2020 12:58:50 +0800 Subject: [PATCH] i2c: sprd: use a specific timeout to avoid system hang up issue commit 0b884fe71f9ee6a5df35e677154256ea2099ebb8 upstream. If the i2c device SCL bus being pulled up due to some exception before message transfer done, the system cannot receive the completing interrupt signal any more, it would not exit waiting loop until MAX_SCHEDULE_TIMEOUT jiffies eclipse, that would make the system seemed hang up. To avoid that happen, this patch adds a specific timeout for message transfer. Fixes: 8b9ec0719834 ("i2c: Add Spreadtrum I2C controller driver") Signed-off-by: Linhua Xu Signed-off-by: Chunyan Zhang [wsa: changed errno to ETIMEDOUT] Signed-off-by: Wolfram Sang Signed-off-by: Greg Kroah-Hartman --- drivers/i2c/busses/i2c-sprd.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/i2c/busses/i2c-sprd.c b/drivers/i2c/busses/i2c-sprd.c index b432e7580458..b2dc80286464 100644 --- a/drivers/i2c/busses/i2c-sprd.c +++ b/drivers/i2c/busses/i2c-sprd.c @@ -72,6 +72,8 @@ /* timeout (ms) for pm runtime autosuspend */ #define SPRD_I2C_PM_TIMEOUT 1000 +/* timeout (ms) for transfer message */ +#define I2C_XFER_TIMEOUT 1000 /* SPRD i2c data structure */ struct sprd_i2c { @@ -244,6 +246,7 @@ static int sprd_i2c_handle_msg(struct i2c_adapter *i2c_adap, struct i2c_msg *msg, bool is_last_msg) { struct sprd_i2c *i2c_dev = i2c_adap->algo_data; + unsigned long time_left; i2c_dev->msg = msg; i2c_dev->buf = msg->buf; @@ -273,7 +276,10 @@ static int sprd_i2c_handle_msg(struct i2c_adapter *i2c_adap, sprd_i2c_opt_start(i2c_dev); - wait_for_completion(&i2c_dev->complete); + time_left = wait_for_completion_timeout(&i2c_dev->complete, + msecs_to_jiffies(I2C_XFER_TIMEOUT)); + if (!time_left) + return -ETIMEDOUT; return i2c_dev->err; }