Re: [PATCH] mmc: dw_mmc: Fix hang on data CRC error

[Jaehoon Chung]

On 7/14/21 8:49 PM, Vincent Whitchurch wrote:
> On Thu, Jul 01, 2021 at 12:06:31AM +0200, Jaehoon Chung wrote:
>> On 6/30/21 7:22 PM, Vincent Whitchurch wrote:
>>> When a Data CRC interrupt is received, the driver disables the DMA, then
>>> sends the stop/abort command and then waits for Data Transfer Over.
>>>
>>> However, sometimes, when a data CRC error is received in the middle of a
>>> multi-block write transfer, the Data Transfer Over interrupt is never
>>> received, and the driver hangs and never completes the request.
>>>
>>> The driver sets the BMOD.SWR bit (SDMMC_IDMAC_SWRESET) when stopping the
>>> DMA, but according to the manual CMD.STOP_ABORT_CMD should be programmed
>>> "before assertion of SWR".  Do these operations in the recommended
>>> order.  With this change the Data Transfer Over is always received
>>> correctly in my tests.
>>
>> I will check with your patch. I didn't see any CRC error on my targets before.
> 
> Have you had a chance to check it?  You can use the fault-injection
> patch if you want to trigger aborted transfers without getting real CRC
> errors:
> 
>  https://protect2.fireeye.com/v1/url?k=96c33914-c958001f-96c2b25b-002590f5b904-9a89d187f33934b7&q=1&e=308eae3a-44b8-43d7-be54-24e9b850f4ad&u=https%3A%2F%2Flore.kernel.org%2Flinux-mmc%2F20210701080534.23138-1-vincent.whitchurch%40axis.com%2F
>