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

[Marcel Ziswiler]

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.