AST2600 i2c irq issue

[Jae Hyun Yoo]

Hi Eddie,

On 10/22/2019 1:24 PM, Eddie James wrote:

[...]

> 7: irq[00000000] before[rx] after[stop]

'irq[]' here and '10[]' below are the same register. This log means an
interrupt came with empty status.

>      00[00008001]
>      04[007ee005]
>      08[00000000]
>      0c[0000607f]
>      10[00000004]    <<< this is interesting. this has changed since the 
> start of the interrupt handler.

The interrupt status was updated lately at here. Looks like there is a
timing gap in H/W between interrupt triggering and status updating. I
haven't seen this issue in previous H/W versions.

This issue can be resolved by your patch but ultimately this issue
should be fixed in AST2600 A1 revision H/W if possible so that we can
remove the unnecessary interrupt handling.

Thanks,

Jae