[REGRESSION 4.10] dw_mmc: failures on Rockchip rk3288 veyron boards

[Brian Norris]

Hi,

On Thu, Mar 30, 2017 at 02:11:19PM +0900, Jaehoon Chung wrote:
> On 03/30/2017 11:53 AM, Brian Norris wrote:
> > On Thu, Mar 30, 2017 at 10:18:59AM +0800, Eddie Cai wrote:
> >> I test on rk3288 firefly reload with 4.11-rc4. It work fine.
> > 
> > OK, thanks for checking.
> > 
> >>> On Thu, Mar 30, 2017 at 09:32:22AM +0800, Shawn Lin wrote:
> >>>> Hi Brian,
> >>>>
> >>>> On 2017/3/30 9:17, Brian Norris wrote:
> >>>>> Hi all,
> >>>>>
> >>>>> I haven't managed to get as far as a bugfix for this, but I've bisected
> >>>>> some issues seen on v4.10+ with a Chromebook of the Veyron family (Jaq,
> >>>>> in particular). v4.9 works fine.
> > 
> > [...]
> > 
> > By the way, Kevin (CC'd) says he noticed similiar Wifi issues on an
> > Exynos 5800 Peach chromebook, but not on an Exynos 5250 Snow chromebook.	
> > I haven't picked these apart yet to see what the differences and
> > similarities are, but presumably it's not actually a Rockchip-specific
> > bug. Maybe related to the way power sequencing is plumbed for these, for
> > example?
> 
> I'm not sure but if card-detecting is polling, the timing issue could be occurred.

I don't know much about MMC in general, nor about this driver. Any
chance you'd accept reverts of the patches in question though? This is a
huge regression, and there were only a few relevant changes that seem to
have triggered this. I can try to come up with something targeted, but
I'm not going to even try if that'd get rejected up front.

Brian