Due to the relatively low priority of the isr_thread, when the CPU
load is high, the execution of sprd_i2c_isr_thread will be delayed.
After the waiting time is exceeded, the I2C driver will perform
operations such as disabling the I2C controller. Later, when
sprd_i2c_isr_thread is called by the CPU, there will be kernel panic
caused by illegal access to the IIC register. After pressure testing,
we found that increasing the IIC waiting time to 10 seconds can
avoid this problem.

Fixes: 0b884fe71f9e ("i2c: sprd: use a specific timeout to avoid system hang up issue")
Cc: <stable@vger.kernel.org> # v5.11+
Signed-off-by: Huangzheng Lai <Huangzheng.Lai@unisoc.com>
---
 drivers/i2c/busses/i2c-sprd.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-sprd.c b/drivers/i2c/busses/i2c-sprd.c
index b65729ba7d5a..dbdac89ad482 100644
--- a/drivers/i2c/busses/i2c-sprd.c
+++ b/drivers/i2c/busses/i2c-sprd.c
@@ -74,7 +74,7 @@
 /* timeout (ms) for pm runtime autosuspend */
 #define SPRD_I2C_PM_TIMEOUT	1000
 /* timeout (ms) for transfer message */
-#define I2C_XFER_TIMEOUT	1000
+#define I2C_XFER_TIMEOUT	10000
 /* dynamic modify clk_freq flag  */
 #define I2C_3M4_FLAG		0x0100
 #define I2C_1M_FLAG		0x0080
-- 
2.17.1

Hi Huangzheng,

On Mon, Oct 23, 2023 at 04:11:57PM +0800, Huangzheng Lai wrote:
> Due to the relatively low priority of the isr_thread, when the CPU
> load is high, the execution of sprd_i2c_isr_thread will be delayed.
> After the waiting time is exceeded, the I2C driver will perform
> operations such as disabling the I2C controller. Later, when
> sprd_i2c_isr_thread is called by the CPU, there will be kernel panic
> caused by illegal access to the IIC register. After pressure testing,
> we found that increasing the IIC waiting time to 10 seconds can
> avoid this problem.
> 
> Fixes: 0b884fe71f9e ("i2c: sprd: use a specific timeout to avoid system hang up issue")
> Cc: <stable@vger.kernel.org> # v5.11+
> Signed-off-by: Huangzheng Lai <Huangzheng.Lai@unisoc.com>

Acked-by: Andi Shyti <andi.shyti@kernel.org>

Andi

> ---
>  drivers/i2c/busses/i2c-sprd.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/i2c/busses/i2c-sprd.c b/drivers/i2c/busses/i2c-sprd.c
> index b65729ba7d5a..dbdac89ad482 100644
> --- a/drivers/i2c/busses/i2c-sprd.c
> +++ b/drivers/i2c/busses/i2c-sprd.c
> @@ -74,7 +74,7 @@
>  /* timeout (ms) for pm runtime autosuspend */
>  #define SPRD_I2C_PM_TIMEOUT	1000
>  /* timeout (ms) for transfer message */
> -#define I2C_XFER_TIMEOUT	1000
> +#define I2C_XFER_TIMEOUT	10000
>  /* dynamic modify clk_freq flag  */
>  #define I2C_3M4_FLAG		0x0100
>  #define I2C_1M_FLAG		0x0080
> -- 
> 2.17.1
>

On 10/23/2023 4:11 PM, Huangzheng Lai wrote:
> Due to the relatively low priority of the isr_thread, when the CPU
> load is high, the execution of sprd_i2c_isr_thread will be delayed.
> After the waiting time is exceeded, the I2C driver will perform
> operations such as disabling the I2C controller. Later, when
> sprd_i2c_isr_thread is called by the CPU, there will be kernel panic
> caused by illegal access to the IIC register. After pressure testing,
> we found that increasing the IIC waiting time to 10 seconds can
> avoid this problem.
> 
> Fixes: 0b884fe71f9e ("i2c: sprd: use a specific timeout to avoid system hang up issue")
> Cc: <stable@vger.kernel.org> # v5.11+
> Signed-off-by: Huangzheng Lai <Huangzheng.Lai@unisoc.com>

Looks reasonable to me.
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>

> ---
>   drivers/i2c/busses/i2c-sprd.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/i2c/busses/i2c-sprd.c b/drivers/i2c/busses/i2c-sprd.c
> index b65729ba7d5a..dbdac89ad482 100644
> --- a/drivers/i2c/busses/i2c-sprd.c
> +++ b/drivers/i2c/busses/i2c-sprd.c
> @@ -74,7 +74,7 @@
>   /* timeout (ms) for pm runtime autosuspend */
>   #define SPRD_I2C_PM_TIMEOUT	1000
>   /* timeout (ms) for transfer message */
> -#define I2C_XFER_TIMEOUT	1000
> +#define I2C_XFER_TIMEOUT	10000
>   /* dynamic modify clk_freq flag  */
>   #define I2C_3M4_FLAG		0x0100
>   #define I2C_1M_FLAG		0x0080