Re: [PATCH 01/28] ARM: tegra: apalis_t30: enable broken-hpi on emmc

From: Dmitry Osipenko
Date: Tue Jul 24 2018 - 10:55:20 EST


On Tuesday, 24 July 2018 17:26:58 MSK Marcel Ziswiler wrote:
> On Tue, 2018-07-24 at 17:03 +0300, Dmitry Osipenko wrote:
>
> > On Sunday, 22 July 2018 19:49:09 MSK Marcel Ziswiler wrote:
> >
> > > From: Marcel Ziswiler <marcel.ziswiler@xxxxxxxxxxx>
> > >
> > > Avoid eMMC issues by specifying broken-hpi.
> > >
> > > Signed-off-by: Marcel Ziswiler <marcel.ziswiler@xxxxxxxxxxx>
> > >
> > > ---
> >
> >
> > Is it a specific eMMC card model that has broken HPI or it is a host
> > controller bug?
>
>
> That is a very good question. So far we only have confirmation that at
> least some eMMCs from Hynix resp. SKHynix definitely do have bad
> firmware. I also found out that ASUS resp. Google did disable HPI on
> their Nexus 7 tablet. Therefore, we also disabled HPI quite a while ago
> in our downstream BSPs which we successfully validated & verified doing
> power cuts and running stress tests in our temperature chambers. I
> guess we would have to run more extensive tests with mainline with and
> without this setting to be able to really answer your question. For now
> I just successfully run a few Apalis T30 and Colibri T30 modules with
> this setting over the weekend doing both hdparm -t as well as dding
> some urandom files to the eMMC in a loop without seeing any issues.

The broken-hpi quirk was added for the Hynix cards specifically in [0]. Maybe
you should just extend the mmc_ext_csd_fixups list in [1] with another OEM ID?

[0] https://patchwork.kernel.org/patch/9168455/
[1] drivers/mmc/core/quirks.h