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authorChunyan Zhang <chunyan.zhang@unisoc.com>2020-12-14 07:58:50 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-01-17 16:04:21 +0300
commit1bf68c17797073b4fc1459b8584bf98f0b05d377 (patch)
tree621ee75735b5f441cc1bc12257f785d0441661a3
parent15d97f9fd9b52c54b76e4eec3f08b2d7b15e13be (diff)
downloadlinux-1bf68c17797073b4fc1459b8584bf98f0b05d377.tar.xz
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 <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>
-rw-r--r--drivers/i2c/busses/i2c-sprd.c8
1 files changed, 7 insertions, 1 deletions
diff --git a/drivers/i2c/busses/i2c-sprd.c b/drivers/i2c/busses/i2c-sprd.c
index a94e724f51dc..bb1478e781c4 100644
--- a/drivers/i2c/busses/i2c-sprd.c
+++ b/drivers/i2c/busses/i2c-sprd.c
@@ -71,6 +71,8 @@
/* 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;
}