[U-Boot] [PATCH 1/2] arm: timer: factor out FSL arch timer erratum workaround

[Andre Przywara]

Hi,

On 03/07/18 21:51, Andreas Färber wrote:
> Am 03.07.2018 um 01:08 schrieb Andreas Färber:
>> Am 02.07.2018 um 10:01 schrieb Jagan Teki:
>>> On Wed, Jun 27, 2018 at 6:12 AM, Andre Przywara <andre.przywara at arm.com> wrote:
>>>> At the moment we have the workaround for the Freescale arch timer
>>>> erratum A-008585 merged into the generic timer_read_counter() routine.
>>>> Split those two up, so that we can add other errata workaround more
>>>> easily. Also add an explaining comment on the way.
>>>>
>>>> Signed-off-by: Andre Przywara <andre.przywara at arm.com>
>>>> ---
>>>
>>> Applied both patches, to u-boot-sunxi/master
>>
>> Tested both on top of v2018.07-rc2, fixes the boot for me.
> 
> Actually I saw it again just now, without having touched U-Boot at all.
> Unplugged power, retried, worked. So it seems we've reduced the
> likelihood, but something might still be astray...

There are reports for that happening on the kernel side as well:
http://lists.infradead.org/pipermail/linux-arm-kernel/2018-July/588288.html
(also see the follow-ups)

I suspect the TVAL access is affected as well (this internally accesses
the counter), so we would need to cover this also.
I'd suggest we wait for the kernel side solution and then copy that, but
we keep this patch here in, as it seems to fix far more frequent problems.

Btw: I tried to use the Freescale workaround in U-Boot, but this at
least requires another patch: to fix the problem when the CPU runs at
24MHz. Also it doesn't really help the MMC issue (I saw the same
crashes), as it doesn't cover forward jumps.

Cheers,
Andre.