Re: [PATCH 1/1] CMD12 error recovery support for SD cards

Matt Fleming
2009-09-23T10:26:54Z

On Wed, Sep 16, 2009 at 04:09:11PM +0530, Mahadev Cholachagudda wrote:
> Dear All,
>
> I've a kernel code base of 2.6.28.9, where in I find that CMD12 error
> recovery is not been implemented. It is a wise idea to implement CMD12
> error recovery, that involves sending CMD13 to get the status of the
> card. If the card is in "trans" state, it means CMD12 error shall be
> treated as successfull. If card state is not in "trans", then we have
> to send CMD12 again to stop the data transfer and then checking of the
> card status through CMD13. This sequence is detailed in the
> "Simplified Host Controller specification" on SDCard website. I
> believe this is the case for any controller, though I may be wrong.
>
> With the modification done to the code which is attached as patch to
> the latest mmc git, it is working at our site. And we do see some
> errors with the SDIO controller (proprietary but meets Standard SD
> host controller specification) that we are using.
>
> Request you to comment on the patch.
>

In principal this patch seems OK. However, I recommend reading
Documentation/CodingStyle and sending this patch again once you've fixed
up the coding style and whitespace errors.

Is there a specific reason that you have used mmc_wait_for_req() instead
of mmc_wait_for_cmd() and reusing the "cmd" local variable? The empty
"else" clauses can also probably be deleted.