Re: [PATCH v3 3/4] arm64: dts: qcom: msm8917: Use a shallower cluster state to fix unresponsive idle

[Reza Kurniawan]

On Thu, Oct 22, 2026 at 5:14 PM Konrad Dybcio
<konrad.dybcio@xxxxxxxxxxxxxxxx> wrote:
>
> On 10/22/26 11:41 AM, Reza Kurniawan wrote:
> > MSM8917 is a single cluster SoC, so powering down the cluster means
> > powering down the whole system. This causes two problems:
> >
> > 1. The system becomes unresponsive, even to common interrupts. Waking it
> >    requires an interrupt from the MPM (MSM Power Manager) or scheduling
> >    the MPM to wake the system later. Linux currently has no way of doing
> >    the latter, so the cluster may never resume operation.
> >
> > 2. Entering power collapse blanks the screen. When the state is entered
> >    and exited repeatedly, this shows up as visible flicker.
> >
> > Even if MPM scheduling were implemented, the second problem would remain
> > and it wouldn't fix the system being unresponsive at idle.
> >
> > Replace the idle state with PSCI mode 4 (dubbed GDHS downstream), which
> > is less aggressive and can wake up from conventional interrupt sources.
> >
> > Signed-off-by: Reza Kurniawan <imkyufie@xxxxxxxxx>
> > ---
>
>
> https://lore.kernel.org/lkml/20261005-s2idle_state-v1-0-3c402c66f388@xxxxxxxxxxxxxxxx/
>
> and
>
> https://lore.kernel.org/lkml/20261015-b4-shikra_lpm_addition-v2-0-ac7f1a0d5638@xxxxxxxxxxxxxxxx/
>
> are in flight, you may want to integrate/test them locally!

Thanks for the tip!

>
> Reviewed-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxxxx>
>
> Konrad