Re: [PATCH] drm/msm/devfreq: Insert missing null check in msm_devfreq_idle

From: AngeloGioacchino Del Regno
Date: Wed Nov 17 2021 - 09:09:55 EST

Il 17/11/21 12:11, Marijn Suijten ha scritto:
msm_devfreq_init only initializes the idle_work hrtimer when it succeeds
to create a devfreq instance (devfreq support is optional), yet
msm_devfreq_idle is called unconditionally from retire_submit and queues
work on it. We're seeing:

[ 2.005265] adreno 1c00000.gpu: [drm:msm_devfreq_init] *ERROR* Couldn't initialize GPU devfreq

Followed by a pagefault in:

[ 16.650316] pc : hrtimer_start_range_ns+0x64/0x360
[ 16.650336] lr : msm_hrtimer_queue_work+0x18/0x2c

Moments later. Just like msm_devfreq_active, check if the devfreq
instance is not NULL before proceeding.

Fixes: 658f4c829688 ("drm/msm/devfreq: Add 1ms delay before clamping freq")
Reviewed-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxx>
Signed-off-by: Marijn Suijten <marijn.suijten@xxxxxxxxxxxxxx>

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>