Re: [RFC/PATCH 0/2] mmc: sdhci: Workaround Intel Merrifield issue for HS200

[David Cohen <david.a.cohen@linux.intel.com>]

On Fri, Dec 20, 2013 at 11:00:23AM +0800, Dong Aisheng wrote:
> On Wed, Nov 13, 2013 at 5:49 AM, David Cohen
> <david.a.cohen@linux.intel.com> wrote:
> > On 10/29/2013 10:58 AM, David Cohen wrote:
> >>
> >> Hi,
> >>
> >> SDHCI used to work well on Intel Merrifield until this patch was applied:
> >>
> >> commit 156e14b126ffb6f040bc6f1aff3c51077e42a744
> >> Author: Giuseppe CAVALLARO <peppe.cavallaro@st.com>
> >> Date:   Wed Jun 12 08:16:38 2013 +0200
> >>
> >>      mmc: sdhci: fix caps2 for HS200
> >>
> >>      Although the HC supports HS200 (eMMC) the caps2 are always zero; this
> >>      means there's no way to use the super speed mode (when init the
> >> card).
> >>
> >>      If the HC support SDR104, for SD3.0, so it also supports HS200 for
> >> eMMC
> >>      and this patch just sets the MMC_CAP2_HS200 in the host caps2 field.
> >>
> >> Looks like there is a hw issue with unknown root cause so far.
> >>
> >> Is it acceptable to have the quirk I'm proposing to workaround the issue?
> >
> >
> > Ping. Any comments here?
> >
> 
> Chris,
> Can you pick this one?
> IMX also needs this quirk for imx6q/dl since it can not meet HS200
> timing requirement.
> 
> 
> David,
> Is the unkonwn hw issue in your patch #2 resolved now?
> If yes, you may not need this quirk.
> I could resend it with your sign-off with IMX patches.

Merrifield still needs this quirk to not break MMC support.
This quirk could be applied to 3.13-rc (since merrifield was added to
sdhci-pci.c on 3.13-rc1).

Br, David

> 
> Regards
> Dong Aisheng
> 
> > Br, David Cohen
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> >
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at  http://vger.kernel.org/majordomo-info.html
> > Please read the FAQ at  http://www.tux.org/lkml/