Problem with Multiblock Write in PXA270 MMC Driver

[Larry Martin]

 > so turning multiblock into singleblock solved the issue
 > of writing on those SD cards

Yes, sorry.  Forcing single block write _did_ allow all SD cards under 
test to work with the PXA270 in the Gumstix Verdex Pro.  My client is 
going to use it that way, but it does not seem like a good general 
solution.  I don't know enough of the big picture in the kernel to craft 
a general solution.

I tried adding logic that would force single-block only after one write 
error occurred, but it did not solve the problem.  The failing SD cards 
would not recover after the first error.

Larry

Eric Miao wrote:
> On Tue, Oct 26, 2010 at 10:32 PM, Larry Martin <Larry at gluelogix.com> wrote:
>> This is a followup to:
>> How do you access MMC driver set_ios?
>> http://lists.arm.linux.org.uk/lurker/message/20101007.144606.f7a7fbcd.en.html
>>
>> The real problem turned out to be that some SD cards fail multiblock write
>> with the PXA270 MMC driver.  In our sample, the failing cards were all
>> Sandisk 2GB marked "MADE IN CHINA".  Sandisk verified that they were genuine
>> (i.e. not counterfeit).  Host platform was Gumstix Verdex Pro. Individual
>> units vary in their failures, so it is likely a signal issue on the boards;
>> it could also likely be an opportunity to make the PXA drivers more robust.
>>
>> Full details are at:
>> http://old.nabble.com/Root-Cause%3A-Intermittent-SD-Card-Failures-on-Verdex-Pro-to29985059.html
>>
> 
> I didn't get the point, so turning multiblock into singleblock solved the issue
> of writing on those SD cards or there is still no verified solution?
> 
>> Good luck, MMC Driver Maintainers.
>>
>> --
>> Larry Martin
>> www.GlueLogix.com
>>
>>
>>
>>
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>>
> 
> 

-- 
Larry Martin
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Design, Test and Support of Computerized Systems
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