From: Chunyan Zhang chunyan.zhang@unisoc.com
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 linhua.xu@unisoc.com Signed-off-by: Chunyan Zhang chunyan.zhang@unisoc.com [wsa: changed errno to ETIMEDOUT] Signed-off-by: Wolfram Sang wsa@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/i2c/busses/i2c-sprd.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)
--- 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 i2 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 i2
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; }