bad pmd

[Matt Reimer]

On Tue, Dec 28, 2010 at 11:51 PM, Eric Miao <eric.y.miao at gmail.com> wrote:
> On Tue, Dec 14, 2010 at 11:08 PM, Matt Reimer <mreimer at sdgsystems.com> wrote:
>> On Wed, Dec 8, 2010 at 9:02 AM, Russell King - ARM Linux
>> <linux at arm.linux.org.uk> wrote:
>>> On Tue, Dec 07, 2010 at 12:26:45PM -0500, Aric D. Blumer wrote:
>>>> Matt Reimer and I believe we have found what is going on here.  I've put
>>>> in a fix (no failures yet), but I wanted to bounce it off anyone interested.
>>>>
>>>> The PXA platform does not use the "bad pmd" mapping that Russell
>>>> describes above under normal circumstances, but the PXA resume code
>>>> (arch/arm/mach-pxa/sleep.S) does on resume:
>>>
>>> Good find.
>>>
>>>> I'm using the patch below as a fix for now, but it's hard to know what
>>>> registers are available.  Might be better to just mask it off the lower
>>>> bits in r1 again.
>>>>
>>>>         @ Let us ensure we jump to resume_after_mmu only when the mcr above
>>>>         @ actually took effect.  They call it the "cpwait" operation.
>>>> -       mrc     p15, 0, r1, c2, c0, 0           @ queue a dependency on CP15
>>>> -       sub     pc, r2, r1, lsr #32             @ jump to virtual addr
>>>> +       mrc     p15, 0, r0, c2, c0, 0           @ queue a dependency on CP15
>>>> +       sub     pc, r2, r0, lsr #32             @ jump to virtual addr
>>>
>>> I don't see anything wrong with this.  Any PXA people want to ack this?
>
> Me neither.
>
> Acked-by: Eric Miao <eric.y.miao at gmail.com>
>
>>
>> This patch fixes the problem for us. We have yet to see a failure with
>> this patch applied.
>>
>> Eric, do you concur that this is a proper fix?
>>
>
> This patch is good. Thanks for figuring this out. My bad replying so
> late.
>
> Russell,
>
> Still time for this fix to get into .37?

I've just resent the patch with a proper commit message.

Matt