4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Peter Ujfalusi <peter.ujfalusi@xxxxxx> [ Upstream commit 9a2eba337cacefc95b97c2726e3efdd435b3460e ] Commit cae9ff036eea effectively disabled the drm poll_helper by checking the wrong flag to see if the driver should enable the poll or not: mode_config.poll_enabled is only set to true by poll_init and it is not indicating if the poll is enabled or not. nouveau_display_create() will initialize the poll and going to disable it right away. After poll_init() the mode_config.poll_enabled will be true, but the poll itself is disabled. To avoid the race caused by calling the poll_enable() from different paths, this patch will enable the poll from one place, in the nouveau_display_hpd_work(). In case the pm_runtime is disabled we will enable the poll in nouveau_drm_load() once. Fixes: cae9ff036eea ("drm/nouveau: Don't enabling polling twice on runtime resume") Signed-off-by: Peter Ujfalusi <peter.ujfalusi@xxxxxx> Reviewed-by: Lyude <lyude@xxxxxxxxxx> Signed-off-by: Ben Skeggs <bskeggs@xxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/nouveau/nouveau_display.c | 6 ++---- drivers/gpu/drm/nouveau/nouveau_drm.c | 6 +++--- 2 files changed, 5 insertions(+), 7 deletions(-) --- a/drivers/gpu/drm/nouveau/nouveau_display.c +++ b/drivers/gpu/drm/nouveau/nouveau_display.c @@ -367,6 +367,8 @@ nouveau_display_hpd_work(struct work_str pm_runtime_get_sync(drm->dev->dev); drm_helper_hpd_irq_event(drm->dev); + /* enable polling for external displays */ + drm_kms_helper_poll_enable(drm->dev); pm_runtime_mark_last_busy(drm->dev->dev); pm_runtime_put_sync(drm->dev->dev); @@ -420,10 +422,6 @@ nouveau_display_init(struct drm_device * if (ret) return ret; - /* enable polling for external displays */ - if (!dev->mode_config.poll_enabled) - drm_kms_helper_poll_enable(dev); - /* enable hotplug interrupts */ list_for_each_entry(connector, &dev->mode_config.connector_list, head) { struct nouveau_connector *conn = nouveau_connector(connector); --- a/drivers/gpu/drm/nouveau/nouveau_drm.c +++ b/drivers/gpu/drm/nouveau/nouveau_drm.c @@ -483,6 +483,9 @@ nouveau_drm_load(struct drm_device *dev, pm_runtime_allow(dev->dev); pm_runtime_mark_last_busy(dev->dev); pm_runtime_put(dev->dev); + } else { + /* enable polling for external displays */ + drm_kms_helper_poll_enable(dev); } return 0; @@ -762,9 +765,6 @@ nouveau_pmops_runtime_resume(struct devi ret = nouveau_do_resume(drm_dev, true); - if (!drm_dev->mode_config.poll_enabled) - drm_kms_helper_poll_enable(drm_dev); - /* do magic */ nvif_mask(&device->object, 0x088488, (1 << 25), (1 << 25)); vga_switcheroo_set_dynamic_switch(pdev, VGA_SWITCHEROO_ON);