On Mon, Jun 6, 2022 at 2:13 PM Maximilian Luz luzmaximilian@gmail.com wrote:
Following commit 17e822f7591f ("drm/msm: fix unbalanced pm_runtime_enable in adreno_gpu_{init, cleanup}"), any call to adreno_unbind() will disable runtime PM twice, as indicated by the call trees below:
adreno_unbind() -> pm_runtime_force_suspend() -> pm_runtime_disable()
adreno_unbind() -> gpu->funcs->destroy() [= aNxx_destroy()] -> adreno_gpu_cleanup() -> pm_runtime_disable()
Note that pm_runtime_force_suspend() is called right before gpu->funcs->destroy() and both functions are called unconditionally.
With recent addition of the eDP AUX bus code, this problem manifests itself when the eDP panel cannot be found yet and probing is deferred. On the first probe attempt, we disable runtime PM twice as described above. This then causes any later probe attempt to fail with
[drm:adreno_load_gpu [msm]] *ERROR* Couldn't power up the GPU: -13
preventing the driver from loading.
As there seem to be scenarios where the aNxx_destroy() functions are not called from adreno_unbind(), simply removing pm_runtime_disable() from inside adreno_unbind() does not seem to be the proper fix. This is what commit 17e822f7591f ("drm/msm: fix unbalanced pm_runtime_enable in adreno_gpu_{init, cleanup}") intended to fix. Therefore, instead check whether runtime PM is still enabled, and only disable it in that case.
Fixes: 17e822f7591f ("drm/msm: fix unbalanced pm_runtime_enable in adreno_gpu_{init, cleanup}") Signed-off-by: Maximilian Luz luzmaximilian@gmail.com
Reviewed-by: Rob Clark robdclark@gmail.com
drivers/gpu/drm/msm/adreno/adreno_gpu.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.c b/drivers/gpu/drm/msm/adreno/adreno_gpu.c index 4e665c806a14..f944b69e2a25 100644 --- a/drivers/gpu/drm/msm/adreno/adreno_gpu.c +++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.c @@ -1057,7 +1057,8 @@ void adreno_gpu_cleanup(struct adreno_gpu *adreno_gpu) for (i = 0; i < ARRAY_SIZE(adreno_gpu->info->fw); i++) release_firmware(adreno_gpu->fw[i]);
pm_runtime_disable(&priv->gpu_pdev->dev);
if (pm_runtime_enabled(&priv->gpu_pdev->dev))pm_runtime_disable(&priv->gpu_pdev->dev); msm_gpu_cleanup(&adreno_gpu->base);}
2.36.1