Re: [PATCH] MMC: Add 400ms to CAFE SD controller resume path

[Pierre Ossman]

On Wed, 13 May 2009 20:05:56 +0000
Deepak Saxena <dsaxena@xxxxxxxxxxx> wrote:

> 
> The CAFE SD controller takes a long time to completely resume
> and w/o this patch, we do not redetect an existing card but
> instead detect it as a new one. Even with MMC_UNSAFE_RESUME
> enabled, this leads to the partition table on the device being
> wiped out.
>     
> See http://dev.laptop.org/ticket/6532 for gory details.
> 
> Signed-off-by: Deepak Saxena <dsaxena@xxxxxxxxxx>
> 

Reading through that report, I don't believe you properly worked around
the bug. You only avoid bug 1339, but that's only mildly related.

What this workaround does is to make sure that MMC_UNSAFE_RESUME
actually works. But if you change cards during suspend, the VFS bug
should reappear and you'll corrupt the partition table.

And as for 1339, has there been any more work done on why this problem
doesn't appear in OFW? I'd be a lot happier if we could make things
work without artificial delays.

RGds
-- 
     -- Pierre Ossman

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