Re: [PATCH v2 00/14] Add Qualcomm SD Card Controller support

[Bjorn Andersson]

On Fri, May 23, 2014 at 1:11 AM, Srinivas Kandagatla
<srinivas.kandagatla@xxxxxxxxxx> wrote:
> On 23/05/14 08:50, Ulf Hansson wrote:
[...]
>> It seems like you had some CRC issues during read/write? Did you
>> manage to resolve that issue?
>
>
> Bjorn is using different SOC and board than the IFC6410 Am testing on, so
> its completely different setup.
> on IFC6410 we did lot of stress testing and no issues seen. so suspecting
> the issues are very specific to that board or the eMMC Bjorn is using.
>
> We are suspecting that the CRC issues are due to the fact that there is no
> code to manage regulators. My test setup uses dummy regulator, and the eMMC
> and external SD cards seems to be Ok with default voltages.
>
> Am not sure if thats the same with Bjorn's board.

I started off by using the same setup as you; relying on the boot leaving
everything in a working condition and using fixed-regulator; with that setup
I saw the CRC issues.

I then introduced my rpm and regulator driver and it didn't change anything
related to the CRC error behaviour.

I have verified that I have the right pinconf and the clocks seems to match
what we have with working codeaurora based SW.
One thing that I did notice is that we run our devices with
MMC_CAP_UHS_DDR50, while Qualcomm doesn't, but I have not been
able to introduce a change in behaviour by modifying the caps.

I do see the same problem both on 8960 and on 8064; although on 8064
it's much worse.


I will do some more debugging to see if I can find any further differences
in the two setups.

Regards,
Bjorn
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