3.16.62-rc1 review patch. If anyone has any objections, please let me know.
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From: Lyude Paul lyude@redhat.com
commit 6833fb1ec120bf078e1a527c573a09d4de286224 upstream.
It's true we can't resume the device from poll workers in nouveau_connector_detect(). We can however, prevent the autosuspend timer from elapsing immediately if it hasn't already without risking any sort of deadlock with the runtime suspend/resume operations. So do that instead of entirely avoiding grabbing a power reference.
Signed-off-by: Lyude Paul lyude@redhat.com Reviewed-by: Karol Herbst kherbst@redhat.com Acked-by: Daniel Vetter daniel@ffwll.ch Cc: Lukas Wunner lukas@wunner.de Signed-off-by: Ben Skeggs bskeggs@redhat.com Signed-off-by: Ben Hutchings ben@decadent.org.uk --- drivers/gpu/drm/nouveau/nouveau_connector.c | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-)
--- a/drivers/gpu/drm/nouveau/nouveau_connector.c +++ b/drivers/gpu/drm/nouveau/nouveau_connector.c @@ -256,12 +256,16 @@ nouveau_connector_detect(struct drm_conn nv_connector->edid = NULL; }
- /* Outputs are only polled while runtime active, so acquiring a - * runtime PM ref here is unnecessary (and would deadlock upon - * runtime suspend because it waits for polling to finish). + /* Outputs are only polled while runtime active, so resuming the + * device here is unnecessary (and would deadlock upon runtime suspend + * because it waits for polling to finish). We do however, want to + * prevent the autosuspend timer from elapsing during this operation + * if possible. */ - if (!drm_kms_helper_is_poll_worker()) { - ret = pm_runtime_get_sync(connector->dev->dev); + if (drm_kms_helper_is_poll_worker()) { + pm_runtime_get_noresume(dev->dev); + } else { + ret = pm_runtime_get_sync(dev->dev); if (ret < 0 && ret != -EACCES) return conn_status; } @@ -332,10 +336,8 @@ detect_analog:
out:
- if (!drm_kms_helper_is_poll_worker()) { - pm_runtime_mark_last_busy(connector->dev->dev); - pm_runtime_put_autosuspend(connector->dev->dev); - } + pm_runtime_mark_last_busy(dev->dev); + pm_runtime_put_autosuspend(dev->dev);
return conn_status; }