[PATCH] ARM errata: Possible cache data corruption with hit-under-miss enabled

Catalin Marinas catalin.marinas at arm.com
Wed Aug 10 06:31:39 EDT 2011


On Tue, Aug 09, 2011 at 11:06:55PM +0100, Siarhei Siamashka wrote:
> On Mon, Aug 8, 2011 at 4:26 PM, Catalin Marinas <catalin.marinas at arm.com> wrote:
> > On Mon, Aug 08, 2011 at 12:43:00PM +0100, Siarhei Siamashka wrote:
> >> On Mon, Aug 8, 2011 at 1:02 PM, Catalin Marinas <catalin.marinas at arm.com> wrote:
> >> > On Mon, Aug 08, 2011 at 07:32:28AM +0100, Siarhei Siamashka wrote:
> >> >> From: Catalin Marinas <catalin.marinas at arm.com>
> >> >>
> >> >> This patch is a workaround for the 364296 ARM1136 r0pX erratum (possible
> >> >> cache data corruption with hit-under-miss enabled). It sets the
> >> >> undocumented bit 31 in the auxiliary control register and the FI bit in
> >> >> the control register, thus disabling hit-under-miss without putting the
> >> >> processor into full low interrupt latency mode.
> >> >>
> >> >> Signed-off-by: Catalin Marinas <catalin.marinas at arm.com>
> >> >> Tested-by: Siarhei Siamashka <siarhei.siamashka at gmail.com>
> >> >
> >> > I haven't pushed this workaround in the past as I wasn't sure there is
> >> > production hardware affected. I recall you mentioned Nokia N800, do you
> >> > know which CPU revision does this have?
> >>
> >> [    0.000000] CPU: ARMv6-compatible processor [4107b362] revision 2
> >> (ARMv6TEJ), cr=00e5387f
> >> [    0.000000] CPU: VIPT aliasing data cache, unknown instruction
> >> cache
> >> [    0.000000] Machine: Nokia N810
> >> [    0.000000] Memory policy: ECC disabled, Data cache writeback
> >> [    0.000000] OMAP2420
> >>
> >> # cat /proc/cpuinfo
> >> Processor       : ARMv6-compatible processor rev 2 (v6l)
> >> BogoMIPS        : 213.72
> >> Features        : swp half thumb fastmult vfp edsp java
> >> CPU implementer : 0x41
> >> CPU architecture: 6TEJ
> >> CPU variant     : 0x0
> >> CPU part        : 0xb36
> >> CPU revision    : 2
> >>
> >> Hardware        : Nokia N810
> >> Revision        : 0000
> >> Serial          : 0000000000000000
> > ...
> >> Would you be so kind to update the patch?
> >
> > OK, I'll update it and post the patch in the next day or so.
> 
> Thanks a lot. I'll be sure to test it and respond to confirm that it
> works fine (or not).

See below. Thanks.

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