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

[Marcel Ziswiler]

On Tue, 2018-07-24 at 17:55 +0300, Dmitry Osipenko wrote:
> 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

Ah, interesting, somehow I missed how that works. Let me give that a
try and if it does work I may make use of this in a v2.

Thanks for the tip, Dmitry.