[PATCH] mmc: failure of block read wait for long time

[Ghorai, Sukumar]

Chris,

> -----Original Message-----
> From: Russell King - ARM Linux [mailto:linux at arm.linux.org.uk]
> Sent: Monday, September 20, 2010 7:07 PM
> To: Adrian Hunter
> Cc: Ghorai, Sukumar; linux-mmc at vger.kernel.org; linux-arm-
> kernel at lists.infradead.org
> Subject: Re: [PATCH] mmc: failure of block read wait for long time
> 
> On Mon, Sep 20, 2010 at 04:09:15PM +0300, Adrian Hunter wrote:
> > The SD/MMC protocol does not indicate which sector has the error.
> > There is no possibility of trying the ith+1-segment because i is
> > unknown.
> 
> Not entirely true.
> 
> I seem to remember that the MMC protocol (and probably SD protocol)
> provides an ack at the end of each data block to say whether the data
> block was correct or not.
> 
> Some hosts tell you when they receive this ack, and you can track how
> many blocks have been successfully read without error.  The ARM MMCI
> primecell does this.
> 
> However, some hosts don't give you this information, in which case you
> don't know where the error occurred in the read - so when a read fails,
> you can only safely report that no bytes were read successfully.  This
> means that even if the error was on the last block, there's no way to
> know this.
[Ghorai]
Would you please review and merge this patch [1] (attached too)?
[1] http://comments.gmane.org/gmane.linux.kernel.mmc/2714


-------------- next part --------------
A non-text attachment was scrubbed...
Name: 0001-mmc-failure-of-block-read-wait-for-long-time.patch
Type: application/octet-stream
Size: 1114 bytes
Desc: 0001-mmc-failure-of-block-read-wait-for-long-time.patch
URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20100922/ee9f688f/attachment.obj>