Re: [PATCH V2 3/6] mmc: block: Be sure to wait while busy in CQE error recovery

[Adrian Hunter <adrian.hunter@intel.com>]

On 3/11/23 12:48, Avri Altman wrote:
>> STOP command does not guarantee to wait while busy, but subsequent
>> command MMC_CMDQ_TASK_MGMT to discard the queue will fail if the
>> card is busy, so be sure to wait by employing mmc_poll_for_busy().
> Doesn't the Task Discard Sequence expects you to check CQDPT[i]==1
> before sending MMC_CMDQ_TASK_MGMT to discard task id i?

We do not clear individual tasks.  Instead the MMC_CMDQ_TASK_MGMT is
sent with the op-code to "discard entire queue", which will also
work even if the queue is empty. Refer JESD84-B51A,
6.6.39.6 CMDQ_TASK_MGMT and Table 43 — Task Management op-codes.

> 
> Thanks,
> Avri
> 
>>
>> Fixes: 72a5af554df8 ("mmc: core: Add support for handling CQE requests")
>> Cc: stable@vger.kernel.org
>> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
>> ---
>>  drivers/mmc/core/core.c | 2 ++
>>  1 file changed, 2 insertions(+)
>>
>> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index
>> 3d3e0ca52614..befde2bd26d3 100644
>> --- a/drivers/mmc/core/core.c
>> +++ b/drivers/mmc/core/core.c
>> @@ -553,6 +553,8 @@ int mmc_cqe_recovery(struct mmc_host *host)
>>         cmd.busy_timeout = MMC_CQE_RECOVERY_TIMEOUT;
>>         mmc_wait_for_cmd(host, &cmd, 0);
>>
>> +       mmc_poll_for_busy(host->card, MMC_CQE_RECOVERY_TIMEOUT,
>> true,
>> + MMC_BUSY_IO);
>> +
>>         memset(&cmd, 0, sizeof(cmd));
>>         cmd.opcode       = MMC_CMDQ_TASK_MGMT;
>>         cmd.arg          = 1; /* Discard entire queue */
>> --
>> 2.34.1
>