[PATCH v3] i2c: aspeed: Reset the i2c controller when timeout occurs

From: Tommy Huang
Date: Tue Sep 05 2023 - 20:49:19 EST


Reset the i2c controller when an i2c transfer timeout occurs.
The remaining interrupts and device should be reset to avoid
unpredictable controller behavior.

Fixes: 2e57b7cebb98 ("i2c: aspeed: Add multi-master use case support")
Cc: Jae Hyun Yoo <jae.hyun.yoo@xxxxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> # v5.1+
Signed-off-by: Tommy Huang <tommy_huang@xxxxxxxxxxxxxx>
Reviewed-by: Andi Shyti <andi.shyti@xxxxxxxxxx>
---
V3: Submit this patch for clearing patch style typo.
---
drivers/i2c/busses/i2c-aspeed.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/i2c/busses/i2c-aspeed.c b/drivers/i2c/busses/i2c-aspeed.c
index 2e5acfeb76c8..5a416b39b818 100644
--- a/drivers/i2c/busses/i2c-aspeed.c
+++ b/drivers/i2c/busses/i2c-aspeed.c
@@ -698,13 +698,16 @@ static int aspeed_i2c_master_xfer(struct i2c_adapter *adap,

if (time_left == 0) {
/*
- * If timed out and bus is still busy in a multi master
- * environment, attempt recovery at here.
+ * In a multi-master setup, if a timeout occurs, attempt
+ * recovery. But if the bus is idle, we still need to reset the
+ * i2c controller to clear the remaining interrupts.
*/
if (bus->multi_master &&
(readl(bus->base + ASPEED_I2C_CMD_REG) &
ASPEED_I2CD_BUS_BUSY_STS))
aspeed_i2c_recover_bus(bus);
+ else
+ aspeed_i2c_reset(bus);

/*
* If timed out and the state is still pending, drop the pending
--
2.25.1