linux-kernel - [PATCH] drm/msm/a6xx: fix frequency not always being restored on GMU resume

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Message-Id: <20200813184420.18448-1-jonathan@marek.ca>
Date:   Thu, 13 Aug 2020 14:44:18 -0400
From:   Jonathan Marek <jonathan@...ek.ca>
To:     freedreno@...ts.freedesktop.org
Cc:     Rob Clark <robdclark@...il.com>, Sean Paul <sean@...rly.run>,
        David Airlie <airlied@...ux.ie>,
        Daniel Vetter <daniel@...ll.ch>,
        Jordan Crouse <jcrouse@...eaurora.org>,
        Sharat Masetty <smasetty@...eaurora.org>,
        Akhil P Oommen <akhilpo@...eaurora.org>,
        linux-arm-msm@...r.kernel.org (open list:DRM DRIVER FOR MSM ADRENO GPU),
        dri-devel@...ts.freedesktop.org (open list:DRM DRIVER FOR MSM ADRENO
        GPU), linux-kernel@...r.kernel.org (open list)
Subject: [PATCH] drm/msm/a6xx: fix frequency not always being restored on GMU resume

The patch reorganizing the set_freq function made it so the gmu resume
doesn't always set the frequency, because a6xx_gmu_set_freq() exits early
when the frequency hasn't been changed. Note this always happens when
resuming GMU after recovering from a hang.

Use a simple workaround to prevent this from happening.

Fixes: 1f60d11423db ("drm: msm: a6xx: send opp instead of a frequency")
---
 drivers/gpu/drm/msm/adreno/a6xx_gmu.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
index b67b38c8fadf..bbbd00020f92 100644
--- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
+++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
@@ -845,6 +845,7 @@ static void a6xx_gmu_set_initial_freq(struct msm_gpu *gpu, struct a6xx_gmu *gmu)
 	if (IS_ERR_OR_NULL(gpu_opp))
 		return;
 
+	gmu->freq = 0; /* so a6xx_gmu_set_freq() doesn't exit early */
 	a6xx_gmu_set_freq(gpu, gpu_opp);
 	dev_pm_opp_put(gpu_opp);
 }
-- 
2.26.1