Messages in this thread | | | Date | Thu, 9 Jun 2022 23:59:03 +0530 | Subject | Re: [Freedreno] [PATCH v2] drm/msm: Grab the GPU runtime in a6xx routines, not the GMU one | From | Akhil P Oommen <> |
| |
On 6/9/2022 11:42 PM, Rob Clark wrote: > On Thu, Jun 9, 2022 at 11:04 AM Akhil P Oommen <quic_akhilpo@quicinc.com> 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@chromium.org> >>> --- >>> >>> 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 *
| |