Hi Shawn,
On 11/17/2016 05:25 PM, Jaehoon Chung wrote:
> 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..
I think your the suggested commit is more correct than me.
After modifying fixes commit ID, then will apply. Thanks!
Best Regards,
Jaehoon Chung
>
> 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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