On 6/9/2022 11:42 PM, Rob Clark wrote:
On Thu, Jun 9, 2022 at 11:04 AM Akhil P Oommen <quic_akhilpo@xxxxxxxxxxx> wrote:
On 6/9/2022 10:17 PM, Douglas Anderson wrote:
>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 fixed that case too. To make that
fix clean, we've moved the pm runtime grabbing into the GPU file.
As a bonus fix with this change, we change the pm_runtime get
functions to check for <= 0 instead of ==. This handles the case where
pm_runtime is disabled.
Fixes: eadf79286a4b ("drm/msm: Check for powered down HW in the devfreq callbacks")
Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
---
Changes in v2:
- Move the set_freq runtime pm grab to the GPU file.
- Use <= for the pm_runtime test, not ==.
drivers/gpu/drm/msm/adreno/a6xx_gmu.c | 9 ---------
drivers/gpu/drm/msm/adreno/a6xx_gpu.c | 13 +++++++++++--
2 files changed, 11 insertions(+), 11 deletions(-)
diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
index 9f76f5b15759..2410815e77b4 100644
--- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
+++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
@@ -125,17 +125,9 @@ void a6xx_gmu_set_freq(struct msm_gpu *gpu, struct dev_pm_opp *opp)
trace_msm_gmu_freq_change(gmu->freq, perf_index);
- /*
- * 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)
- 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);
return;
}
@@ -159,7 +151,6 @@ 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);
}
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 42ed9a3c4905..54efd9b76ea6 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)
You are changing the behavior here when CONFIG_PM is not enabled.
I'd guess the odds of anything working with PM=n are low
fwiw, https://patchwork.freedesktop.org/patch/364077/#comment_672059
Akhil
BR,
-R
-Akhil.
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;
}
@@ -1677,9 +1677,18 @@ static void a6xx_gpu_set_freq(struct msm_gpu *gpu, struct dev_pm_opp *opp)
struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu);
struct a6xx_gpu *a6xx_gpu = to_a6xx_gpu(adreno_gpu);
+ /*
+ * 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(&gpu->pdev->dev) <= 0)
+ return;
+
mutex_lock(&a6xx_gpu->gmu.lock);
a6xx_gmu_set_freq(gpu, opp);
mutex_unlock(&a6xx_gpu->gmu.lock);
+
+ pm_runtime_put(&gpu->pdev->dev);
}
static struct msm_gem_address_space *
