Re: [PATCH 4/4] mmc: sdhci-esdhc-imx: Remove the ENGcm07207 workaround

[Ulf Hansson]

On 29 May 2017 at 10:07, Adrian Hunter <adrian.hunter@xxxxxxxxx> wrote:
> On 03/05/17 13:05, BenoÃt ThÃbaudeau wrote:
>> The SDHCI_QUIRK_NO_MULTIBLOCK quirk was used as a workaround for the
>> ENGcm07207 erratum. However, it caused excruciatingly slow SD transfers
>> (300 kB/s on average), and this erratum actually does not imply that
>> multiple-block transfers are not supported, so this was overkill.
>>
>> The suggested workaround for this erratum is to set SYSCTL.RSTA, but the
>> simple DAT line software reset (which resets the DMA circuit among
>> others) triggered by sdhci_finish_data() in case of errors seems to be
>> sufficient. Indeed, generating errors in a controlled manner on i.MX25
>> using the FEVT register right in the middle of read data transfers
>> without this quirk shows that nothing is written to the buffer by the
>> eSDHC past CMD12, and no extra Auto CMD12 is sent with AC12EN set, so
>> the data transfers on AHB are properly aborted. For write data
>> transfers, neither extra data nor extra Auto CMD12 is sent, as expected.
>> Moreover, after intensive stress tests on i.MX25, removing
>> SDHCI_QUIRK_NO_MULTIBLOCK seems to be safe.
>>
>> Signed-off-by: BenoÃt ThÃbaudeau <benoit@xxxxxxxxxxx>
>
> Aside from one comment below...
>
> I would expect to see Acks from other sdhci-esdhc-imx users.  Nevertheless,
> for sdhci:

Yes, I would also appreciate some ack/tested by, from the
corresponding sdhci variant users of this series.

However, to allow it to get some results from linux-next, I have
queued up this series for next (amending $subject patch according to
the comment from Adrian). Thanks!

>
> Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
>
>

[...]

Kind regards
Uffe