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

[Srinivas Kandagatla]

Hi Bjorn,

Thanks for the update.
On 23/05/14 16:20, Bjorn Andersson wrote:
> 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 think the driver needs some more additional configs in clkreg to 
support UHS_DDR50 mode.. I will try to create a patch for that.

Did you get a chance to test external SD/MMC card?
> 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.
Yes, Please let me know if you need any kind of support in debugging.
We can sync up on IRC on this. Its important that we solve this issue.

Thanks,
srini
> Regards,
> Bjorn
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