AST2500 I2C Controller got stuck in SRXD state

[Tao Ren]

On 9/3/19 2:51 PM, Jae Hyun Yoo wrote:
> On 9/3/2019 2:45 PM, Tao Ren wrote:
>> Hi,
>>
>> I found the issue on Minipack (AST2500) BMC i2c-0: it's multi-master environment with BMC and Bridged-IC.
>>
>> The BMC I2C controller got stuck in SLAVE_RX_DONE state because STOP condition is not detected during one BIC-to-BMC transfer.
>> Because of this, all the subsequent I2C master transactions would fail with timeout.
>> Here is BMC I2C state reported in I2CD14 Command/Status register:
>>
>> - I2CD14[22:19] = 0100b  /* transfer state machine: SLAVE_RX_DONE */
>> - I2CD14[18] = 1 /* sampled SCL line: high/idle */
>> - I2CD14[17] = 1 /* sampled SDA line: high/idle */
>> - I2CD14[16] = 0 /* bus is idle */
>>
>> I'm suspecting it's caused by some flaws in BIC firmware, but can we do something in BMC side to recover the bus?
>> For example:
>>
>> 1) As Jae mentioned earlier, enable slave inactive timeout interrupt and reset bus when the interrupt is delivered?
>>
>> 2) Check I2CD14[22:19] in aspeed_i2c_recover_bus() function and reset bus if needed?
>>
> 
> Hi Tao,
> 
> I made the slave inactive timeout support. Will submit it soon.
> 
> Cheers,
> Jae

Awesome. Thank you Jae.


Cheers,

Tao