Re: [PATCH 1/3] firmware/psci: Fix cpu_resume entry points with THUMB2_KERNEL

From: Florian Fainelli
Date: Fri Sep 28 2018 - 13:50:47 EST


On 09/28/2018 06:47 AM, Mark Rutland wrote:
> On Thu, Sep 27, 2018 at 12:27:09PM -0700, Florian Fainelli wrote:
>> When THUMB2_KERNEL is enabled, we would be failing to resume from an
>> idle or system suspend call where the reentry point is set to
>> cpu_resume() because that function is in Thumb2. Utilize
>> cpu_resume_arm() for ARM 32-bit kernels which takes care of the mode
>> switching for us.
>
> Looking at the PSCI spec, if bit[0] of the entry point address is set,
> the CPU should be placed into thumb state.
>
> So either there's a FW bug here, or perhaps we're stripping bit[0] when
> we do the __pa_symbol() dance.
>
> Which firmware have you seen this with?

This is a custom implementation use with ARCH_BRCMSTB, the same way I
managed to miss it during code review, I missed it again here, sorry
about that and thanks for pointing me in the right direction.
--
Florian