[RFC PATCH dev-5.1 4/6] i2c: aspeed: fix master pending state handling

[Tao Ren]

On 6/20/19 1:34 PM, Jae Hyun Yoo wrote:
> On 6/20/2019 1:30 PM, Tao Ren wrote:
>> On 6/20/19 12:49 PM, Jae Hyun Yoo wrote:
>>> In case of a master pending state, it should not trigger the master
>>> command because this H/W is sharing the same data buffer for slave
>>> and master operation, so this commit fixes the issue with making
>>> the master command triggering happens when the state goes to active
>>> state.
>>>
>>> Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo at linux.intel.com>
>>
>> Thank you Jae for the patch. I believe I hit the bug while debugging BMC-BIC multi-master communication on my Minipack ast2500 BMC platform. Let me apply the patch and run some testing, will try to share my results by this Friday (Pacific Time).
> 
> Thank you Tao for your help for testing it. It would be really helpful
> to complete this patch implementation. Will wait the test results.
> 
> Regards,
> Jae

Hi Jae,

Although my problem is not fixed by this patch, nothing gets worse :) And patch itself looks reasonable to me.

The problem I'm facing is: i2c-0 (multi-master) stays in "SLAVE_ACTIVE" state: slave_state is brought back to SLAVE_START again and again due to SLAVE_MATCH interrupt. I didn't get chance to check master state machine, but I'd assume it's always pending which explains why userspace applications get "connection timed out" error for i2c master transfers. 


Cheers,

Tao