On 11/17/2016 05:08 PM, Shawn Lin wrote:
> Hi Jaehoon,
>
> 在 2016/11/17 15:53, Jaehoon Chung 写道:
>> When OWN bit of dma descriptor is not cleared, then it returns -EINVAL.
>> Then it has to fall back to PIO mode for current transfer.
>>
>> Host controller was already set to bits relevant to DMA operation.
>> If needs to use the PIO mode, Host controller has to stop the DMA
>> operation. (It's more stable than now.)
>>
>
> It looks good to me, but
>
>> When it occurred error, it's not running any request.
>>
>> Fixes: 3b2a067b98b4 ("mmc: dw_mmc: avoid race condition of cpu and IDMAC")
>>
>
> I think the real fixes tag should indicate the another commit,
> 3fc7eaef44dbcbcd60 ("mmc: dw_mmc: Add external dma interface support")
You're right.
But my main problem is "checking OWN bit". Thanks for noticing this commit. :)
Some time..OWN bit is never released..
Best Regards,
Jaehoon Chung
>
> otherwise,
>
> Reviewed-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>
>
>> Signed-off-by: Jaehoon Chung <jh80.chung@xxxxxxxxxxx>
>> ---
>> drivers/mmc/host/dw_mmc.c | 1 +
>> 1 file changed, 1 insertion(+)
>>
>> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
>> index 9341b18..080003b 100644
>> --- a/drivers/mmc/host/dw_mmc.c
>> +++ b/drivers/mmc/host/dw_mmc.c
>> @@ -1058,6 +1058,7 @@ static int dw_mci_submit_data_dma(struct dw_mci *host, struct mmc_data *data)
>> spin_unlock_irqrestore(&host->irq_lock, irqflags);
>>
>> if (host->dma_ops->start(host, sg_len)) {
>> + host->dma_ops->stop(host);
>> /* We can't do DMA, try PIO for this one */
>> dev_dbg(host->dev,
>> "%s: fall back to PIO mode for current transfer\n",
>>
>
>
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