[PATCH] drm/msm: Grab the GPU runtime in a6xx routines, not the GMU one

From: Douglas Anderson
Date: Thu Jun 09 2022 - 10:34:11 EST


>From testing on sc7180-trogdor devices, reading the GMU registers
needs the GMU clocks to be enabled. Those clocks get turned on in
a6xx_gmu_resume(). Confusingly enough, that function is called as a
result of the runtime_pm of the GPU "struct device", not the GMU
"struct device".

Let's grab a reference to the correct device. Incidentally, this makes
us match the a5xx routine more closely.

This is easily shown to fix crashes that happen if we change the GPU's
pm_runtime usage to not use autosuspend. It's also believed to fix
some long tail GPU crashes even with autosuspend.

NOTE: the crashes I've seen were fixed by _only_ fixing
a6xx_gpu_busy(). However, I believe that the same arguments should be
made to a6xx_gmu_set_freq() so I've changed that function too.

Fixes: eadf79286a4b ("drm/msm: Check for powered down HW in the devfreq callbacks")
Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
---

drivers/gpu/drm/msm/adreno/a6xx_gmu.c | 6 +++---
drivers/gpu/drm/msm/adreno/a6xx_gpu.c | 4 ++--
2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
index 9f76f5b15759..b79ad2e0649c 100644
--- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
+++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
@@ -129,13 +129,13 @@ void a6xx_gmu_set_freq(struct msm_gpu *gpu, struct dev_pm_opp *opp)
* This can get called from devfreq while the hardware is idle. Don't
* bring up the power if it isn't already active
*/
- if (pm_runtime_get_if_in_use(gmu->dev) == 0)
+ if (pm_runtime_get_if_in_use(&gpu->pdev->dev) == 0)
return;

if (!gmu->legacy) {
a6xx_hfi_set_freq(gmu, perf_index);
dev_pm_opp_set_opp(&gpu->pdev->dev, opp);
- pm_runtime_put(gmu->dev);
+ pm_runtime_put(&gpu->pdev->dev);
return;
}

@@ -159,7 +159,7 @@ void a6xx_gmu_set_freq(struct msm_gpu *gpu, struct dev_pm_opp *opp)
dev_err(gmu->dev, "GMU set GPU frequency error: %d\n", ret);

dev_pm_opp_set_opp(&gpu->pdev->dev, opp);
- pm_runtime_put(gmu->dev);
+ pm_runtime_put(&gpu->pdev->dev);
}

unsigned long a6xx_gmu_get_freq(struct msm_gpu *gpu)
diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
index 841e47a0b06b..87568d0b6ef8 100644
--- a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
+++ b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
@@ -1659,7 +1659,7 @@ static u64 a6xx_gpu_busy(struct msm_gpu *gpu, unsigned long *out_sample_rate)
*out_sample_rate = 19200000;

/* Only read the gpu busy if the hardware is already active */
- if (pm_runtime_get_if_in_use(a6xx_gpu->gmu.dev) == 0)
+ if (pm_runtime_get_if_in_use(&gpu->pdev->dev) == 0)
return 0;

busy_cycles = gmu_read64(&a6xx_gpu->gmu,
@@ -1667,7 +1667,7 @@ static u64 a6xx_gpu_busy(struct msm_gpu *gpu, unsigned long *out_sample_rate)
REG_A6XX_GMU_CX_GMU_POWER_COUNTER_XOCLK_0_H);


- pm_runtime_put(a6xx_gpu->gmu.dev);
+ pm_runtime_put(&gpu->pdev->dev);

return busy_cycles;
}
--
2.36.1.255.ge46751e96f-goog