Re: 2GB MMC/SD cards

Jordan Crouse
2006-06-05T22:30:07Z

On 03/06/06 23:13 +0200, "Pierre Ossman" wrote:
> Matt Reimer wrote:
>
> That's what I thought until I looked closer at the Sandisk specs. Until
> we can see what the official specs say, we won't really know what the
> correct behaviour is. The Nokia boys working on the 770 have a copy.
> Perhaps someone here knows how to get in touch with one of them that can
> have a look?

I'm not 100% sure what the community stance is on using the simplified specs.
I do believe the answer lies definitively within, but I'll refrain from
quoting it to avoid any legal complaints. For the longest time, my gut
feeling has been that 512 byte writes were always accepted - but since all of
our 2G and 4G cards support WRITE_BL_PARTIAL, we haven't had a chance to
prove the argument one way or the other.

We first heard about very large card issues from one of our customers, and
we haven't heard any more problems since we gave them a patch to force the
sector size on all SD/MMC cards to 512 bytes. Thats just anecdotal evidence,
but it is food for thought.

Jordan

--
Jordan Crouse
Senior Linux Engineer
AMD - Personal Connectivity Solutions Group
<www.amd.com/embeddedprocessors>