All OMAP platforms: MMC is broken

[Ulf Hansson]

On 6 October 2015 at 11:44, Tony Lindgren <tony at atomide.com> wrote:
> * Russell King - ARM Linux <linux at arm.linux.org.uk> [151006 02:04]:
>> On Mon, Oct 05, 2015 at 07:38:13PM +0100, Russell King - ARM Linux wrote:
>> > On Mon, Oct 05, 2015 at 10:11:56AM -0700, Tony Lindgren wrote:
>> > > * Tony Lindgren <tony at atomide.com> [151005 07:57]:
>> > > > * Tony Lindgren <tony at atomide.com> [151005 07:44]:
>> > > > > * Tony Lindgren <tony at atomide.com> [151005 04:28]:
>> > > > >
>> > > > > Based on some tests it seems that the duovero unpaired regulator usage
>> > > > > is fixed by reverting:
>> > > > >
>> > > > > c55d7a055364 ("mmc: host: omap_hsmmc: use regulator_is_enabled to
>> > > > > find pbias status")
>> > > >
>> > > > With commit c55d7a055364 my guess is that the PBIAS regulator is
>> > > > already on from an earlier MMC probe and getting re-enabled when
>> > > > a deferred probe happens?
>> > >
>> > > Unless somebody has a better fix in mind for the above, I suggest
>> > > we revert it for the -rc kernel.
>> >
>> > Let me try reverting that in my build tree, and...
>> >
>> > > > > And it seems that omap3 legacy MMC is broken earlier in the
>> > > > > series with:
>> > > > >
>> > > > > 7d607f917008 ("mmc: host: omap_hsmmc: use
>> > > > > devm_regulator_get_optional() for vmmc")
>> > > > >
>> > > > > This one does not cleanly revert so have not yet tried reverting
>> > > > > it.
>> > > >
>> > > > And with commit 7d607f917008 I'm guessing we can't return an
>> > > > error if the PBIAS regulator does not exist as that's not there
>> > > > for the legacy booting.
>> > >
>> > > For omap3 legacy booting, we keep getting -EPROBE_DEFER for
>> > > all the optional regulators.
>> > >
>> > > Something like the following might be the minimal fix for the -rc
>> > > cycle?
>> >
>> > applying this patch.  If that gets things going again, then we
>> > _definitely_ should get both of these to Linus ASAP.  The breakage
>> > has been around far too long already.
>>
>> Last night's build shows that this fixes the non-DT LDP3430 booting, but
>> DT-based LDP3430 and SDP4430 both remain broken for the same reason -
>> neither can find their SD cards.
>
> Hmm DT-based boot finds the MMC card for LDP, dmesg below from DT boot [1].
> Looks like you're on on -rc4 and not -rc3. My guess is that MMC is not
> working for you with DT-based booting because you don't seem to have
> CONFIG_REGULATOR_PBIAS in your seed config for. Care to try enabling that
> for both your omap3 and omap4 seed config files?
>
>> We're at -rc4.  That means we're could be only three weeks away from 4.3
>> being released, and DT OMAP has yet to boot _once_ here.
>>
>> What I find *totally* unacceptable is the lack of reaction from the MMC
>> and TI people: it's just like "we'll break your crap, and we'll ignore
>> reports of regressions."  That is *not* acceptable in any shape or form,
>> and people who do this _should_ have their future patches ignored until
>> they demonstrate that they understand the need to not break stuff.
>>
>> I'm at the point of suggesting that there should be a moritorium on all
>> OMAP related development for 4.4: delay all development to 4.5, and have
>> 4.4 as a pure bug-fixing _only_ cycle for OMAP.  If 4.3 is released and
>> OMAP is still broken, then I don't think there's an option on that.
>>
>> Maybe the idea that development work won't hit mainline for another 4
>> months will help focus the minds on not breaking stuff and then ignoring
>> regression reports.
>
> I'm thinking along the same lines. In general, I do not and will not
> apply any patches that are not fixes until all critical regressions are
> out of the way. So not applying anything new for v4.4 until these MMC
> regressions are fixed for v4.3.
>

Tony, Russell - just wanted to say thanks for putting a big effort in
fixing this. I was expecting support from Kishon, but I guess he's
busy.

Unfortunate, I don't have any of the hardware that fails, otherwise I
would of course be helping out more. The only thing I can think of is
to revert the entire patchset I picked up for 4.3 from Kishon for the
omap_hsmmc driver, but then I am not sure if that would cause other
issues...

Kind regards
Uffe