Re: [PATCH v4 2/2] mmc: sdhci-omap: Don't finish_mrq() on a command error during tuning

From: Faiz Abbas
Date: Fri Mar 29 2019 - 03:43:02 EST


Hi Adrian,

On 28/03/19 1:43 PM, Adrian Hunter wrote:
> On 27/03/19 1:47 PM, Faiz Abbas wrote:
>> Hi Adrian,
>>
>> On 27/03/19 4:45 PM, Adrian Hunter wrote:
>>> On 26/03/19 1:00 PM, Faiz Abbas wrote:
>>>> commit 5b0d62108b46 ("mmc: sdhci-omap: Add platform specific reset
>>>> callback") skips data resets during tuning operation. Because of this,
>>>> a data error or data finish interrupt might still arrive after a command
>>>> error has been handled and the mrq ended. This ends up with a "mmc0: Got
>>>> data interrupt 0x00000002 even though no data operation was in progress"
>>>> error message.
>>>>
>>>> Fix this by adding a platform specific callback for sdhci_irq. Mark the
>>>> mrq as a failure but wait for a data interrupt instead of calling
>>>> finish_mrq().
>>>>
>>>> Signed-off-by: Faiz Abbas <faiz_abbas@xxxxxx>
>>>> ---
>>>> drivers/mmc/host/sdhci-omap.c | 37 +++++++++++++++++++++++++++++++++++
>>>> 1 file changed, 37 insertions(+)
>>>>
>>>> diff --git a/drivers/mmc/host/sdhci-omap.c b/drivers/mmc/host/sdhci-omap.c
>>>> index 5bbed477c9b1..9da2ff9ede8b 100644
>>>> --- a/drivers/mmc/host/sdhci-omap.c
>>>> +++ b/drivers/mmc/host/sdhci-omap.c
>>>> @@ -797,6 +797,42 @@ void sdhci_omap_reset(struct sdhci_host *host, u8 mask)
>>>> sdhci_reset(host, mask);
>>>> }
>>>>
>>>> +#define CMD_ERR_MASK (SDHCI_INT_CRC | SDHCI_INT_END_BIT | SDHCI_INT_INDEX |\
>>>> + SDHCI_INT_TIMEOUT)
>>>> +#define CMD_MASK (CMD_ERR_MASK | SDHCI_INT_RESPONSE)
>>>> +
>>>> +static irqreturn_t sdhci_omap_irq(struct sdhci_host *host, u32 intmask)
>>>> +{
>>>> + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>>>> + struct sdhci_omap_host *omap_host = sdhci_pltfm_priv(pltfm_host);
>>>> +
>>>> + if (omap_host->is_tuning && (intmask & CMD_ERR_MASK)) {
>>>> +
>>>> + /*
>>>> + * Since we are not resetting data lines during tuning
>>>> + * operation, data error or data complete interrupts
>>>> + * might still arrive. Mark this request as a failure
>>>> + * but still wait for the data interrupt
>>>> + */
>>>> + if (intmask & SDHCI_INT_TIMEOUT)
>>>> + host->cmd->error = -ETIMEDOUT;
>>>> + else
>>>> + host->cmd->error = -EILSEQ;
>>>> +
>>>> + sdhci_finish_command(host);
>>>
>>> Would it be possible to set SDHCI_INT_RESPONSE instead of calling
>>> sdhci_finish_command() directly?
>>>
>>
>> It should be possible. But what we are trying to do won't be very clear
>> from the code. Ideally an interrupt handler should not set any interrupt
>> bits, just handle and clear them. Also, setting the RESPONSE bit even
>> when there has been no response seems wrong and makes the code more
>> convoluted.
>
> Well, I am not in favour of exporting sdhci_finish_command().
> So I had a look and it is not obvious why you need to call it.
> What about something this:
>
> if (omap_host->is_tuning && host->cmd && !host->data_early &&
> (intmask & CMD_ERR_MASK)) {
>
> if (intmask & SDHCI_INT_TIMEOUT)
> host->cmd->error = -ETIMEDOUT;
> else
> host->cmd->error = -EILSEQ;
>
> host->cmd = NULL;
>
> sdhci_writel(host, intmask & CMD_MASK, SDHCI_INT_STATUS);
> intmask &= ~CMD_MASK;
> }
>

Yeah. I guess host->cmd = NULL was the only thing that was being done
sdhci_finish_command(). This works with 100 time boot tests for me. Will
post next version.

Thanks,
Faiz