[PATCH v2] RFC: ARM: cache-l2x0: update workaround for PL310 errata 727915

[Will Deacon]

Hi Santosh,

On Mon, May 21, 2012 at 07:04:21AM +0100, Shilimkar, Santosh wrote:
> On Mon, May 21, 2012 at 2:11 AM, Linus Walleij
> <linus.walleij at stericsson.com> wrote:
> > From: Colin Cross <ccross at android.com>
> >
> > ARM errata 727915 for PL310 has been updated to include a new
> > workaround required for PL310 r2p0 for l2x0_flush_all, which also
> > affects l2x0_clean_all in my testing. For r2p0, clean or flush
> > each set/way individually. For r3p0 or greater, use the debug
> > register for cleaning and flushing.
> >
> > Requires exporting the cache_id, sets and ways detected in the
> > init function for later use.
> >
> > Cc: Will Deacon <will.deacon at arm.com>
> > Cc: Santosh Shilimkar <santosh.shilimkar at ti.com>
> > Cc: Per Fransson <per.fransson.ml at gmail.com>
> > Signed-off-by: Colin Cross <ccross at android.com>
> > Signed-off-by: Linus Walleij <linus.walleij at linaro.org>
> > ---
> > I found this thing in the Android tree, it looks like it could
> > be pretty serious so I'm mailing it out. If it is correct I
> > guess it should even be tagged for -stable?
> >
> > v2: what about actually git commit --amend in the rebase changes
> > for -rc7? Sorry for the screwup...
> > ---
> This was observed on OMAP4460 devices. Though the errata
> document doesn't support it, the issue seen with l2 clean was
> indeed fixed $subject fix.

I'm not sure I follow. Which version of the PL310 is in OMAP4460? Are you
saying that the current workaround didn't work but the one in this patch
did? Do you have a testcase?

Cheers,

Will