search for: drm_kms_helper_poll_disable

...rent task is an output poll worker. This can be used + * to select distinct code paths for output polling versus other contexts. + * + * One use case is to avoid a deadlock between the output poll worker and + * the autosuspend worker wherein the latter waits for polling to finish + * upon calling drm_kms_helper_poll_disable(), while the former waits for + * runtime suspend to finish upon calling pm_runtime_get_sync() in a + * connector ->detect hook. + */ +bool drm_kms_helper_is_poll_worker(void) +{ + struct work_struct *work = current_work(); + + return work && work->func == output_poll_execute; +} +EXP...

...th the hub, we end up confusing it and cause it to stop > > > responding for at least 10 seconds > > > - After 5 seconds of being in drm_fb_helper_output_poll_changed(), the > > > pm core attempts to put the GPU into autosuspend, which ends up > > > calling drm_kms_helper_poll_disable() > > > - While the runtime PM core is waiting in drm_kms_helper_poll_disable() > > > for the output poll to finish, we end up finally detecting an MST > > > display > > > - We notice the new display and tries to enable it, which triggers > > > an...

...drm/amd/amdgpu/amdgpu_drv.c @@ -718,6 +718,9 @@ static int amdgpu_pmops_runtime_suspend(struct device *dev) return -EBUSY; } + printk("waiting 12 sec\n"); + msleep(12*1000); + printk("done waiting 12 sec\n"); drm_dev->switch_power_state = DRM_SWITCH_POWER_CHANGING; drm_kms_helper_poll_disable(drm_dev); vga_switcheroo_set_dynamic_switch(pdev, VGA_SWITCHEROO_OFF); diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c index 555fbe5..ee7cf0d 100644 --- a/drivers/gpu/drm/drm_probe_helper.c +++ b/drivers/gpu/drm/drm_probe_helper.c @@ -586,6 +586,7 @@ static vo...

...;linux/vga_switcheroo.h> @@ -718,6 +719,9 @@ static int amdgpu_pmops_runtime_suspend(struct device *dev) return -EBUSY; } + printk("waiting 12 sec\n"); + msleep(12*1000); + printk("done waiting 12 sec\n"); drm_dev->switch_power_state = DRM_SWITCH_POWER_CHANGING; drm_kms_helper_poll_disable(drm_dev); vga_switcheroo_set_dynamic_switch(pdev, VGA_SWITCHEROO_OFF); diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c index 555fbe5..ee7cf0d 100644 --- a/drivers/gpu/drm/drm_probe_helper.c +++ b/drivers/gpu/drm/drm_probe_helper.c @@ -586,6 +586,7 @@ static vo...

...and attempting to > communicate with the hub, we end up confusing it and cause it to stop > responding for at least 10 seconds > - After 5 seconds of being in drm_fb_helper_output_poll_changed(), the > pm core attempts to put the GPU into autosuspend, which ends up > calling drm_kms_helper_poll_disable() > - While the runtime PM core is waiting in drm_kms_helper_poll_disable() > for the output poll to finish, we end up finally detecting an MST > display > - We notice the new display and tries to enable it, which triggers > an atomic commit which triggers a call to pm_runtime_...

...per_output_poll_changed() and attempting to communicate with the hub, we end up confusing it and cause it to stop responding for at least 10 seconds - After 5 seconds of being in drm_fb_helper_output_poll_changed(), the pm core attempts to put the GPU into autosuspend, which ends up calling drm_kms_helper_poll_disable() - While the runtime PM core is waiting in drm_kms_helper_poll_disable() for the output poll to finish, we end up finally detecting an MST display - We notice the new display and tries to enable it, which triggers an atomic commit which triggers a call to pm_runtime_get_sync() - the output p...

...ed + * to select distinct code paths for output polling versus other contexts. + */ +bool drm_kms_helper_is_poll_worker(void) +{ + struct work_struct *work = current_work(); + + return work && work->func == output_poll_execute; +} +EXPORT_SYMBOL(drm_kms_helper_is_poll_worker); + /** * drm_kms_helper_poll_disable - disable output polling * @dev: drm_device diff --git a/include/drm/drm_crtc_helper.h b/include/drm/drm_crtc_helper.h index 76e237bd989b..6914633037a5 100644 --- a/include/drm/drm_crtc_helper.h +++ b/include/drm/drm_crtc_helper.h @@ -77,5 +77,6 @@ void drm_kms_helper_hotplug_event(struct drm_dev...

...ll_enable()'s documentation: Note that calls to enable and disable polling must be strictly ordered, which is automatically the case when they're only call from suspend/resume callbacks. Of course, hotplugs can't really be ordered. They could even happen immediately after we called drm_kms_helper_poll_disable() in nouveau_display_fini(), which can lead to all sorts of issues. Additionally; enabling polling /after/ we call drm_helper_hpd_irq_event() could also mean that we'd miss a hotplug event anyway, since drm_helper_hpd_irq_event() wouldn't bother trying to probe connectors so long as pollin...

Does what it says on the label, a lot of these calls are already handled somewhere else and don't appear to be here for a legitimate reason anymore. Lyude Paul (3): drm/nouveau: Remove useless poll_enable() call in switcheroo_set_state() drm/nouveau: Remove useless poll_disable() call in switcheroo_set_state() drm/nouveau: Remove useless poll_enable() call in drm_load()

Next version of https://patchwork.freedesktop.org/series/48131/ Only changes are new A-Bs and R-Bs Lyude Paul (3): drm/nouveau: Remove useless poll_enable() call in switcheroo_set_state() drm/nouveau: Remove useless poll_disable() call in switcheroo_set_state() drm/nouveau: Remove useless poll_enable() call in drm_load() drivers/gpu/drm/nouveau/nouveau_drm.c | 4 +---

...gt; communicate with the hub, we end up confusing it and cause it to stop > > responding for at least 10 seconds > > - After 5 seconds of being in drm_fb_helper_output_poll_changed(), the > > pm core attempts to put the GPU into autosuspend, which ends up > > calling drm_kms_helper_poll_disable() > > - While the runtime PM core is waiting in drm_kms_helper_poll_disable() > > for the output poll to finish, we end up finally detecting an MST > > display > > - We notice the new display and tries to enable it, which triggers > > an atomic commit which trigg...

...per_output_poll_changed() and attempting to communicate with the hub, we end up confusing it and cause it to stop responding for at least 10 seconds - After 5 seconds of being in drm_fb_helper_output_poll_changed(), the pm core attempts to put the GPU into autosuspend, which ends up calling drm_kms_helper_poll_disable() - While the runtime PM core is waiting in drm_kms_helper_poll_disable() for the output poll to finish, we end up finally detecting an MST display - We notice the new display and tries to enable it, which triggers an atomic commit which triggers a call to pm_runtime_get_sync() - the output p...

Fix a deadlock on hybrid graphics laptops that's been present since 2013: DRM drivers poll connectors in 10 sec intervals. The poll worker is stopped on ->runtime_suspend with cancel_delayed_work_sync(). However the poll worker invokes the DRM drivers' ->detect callbacks, which call pm_runtime_get_sync(). If the poll worker starts after runtime suspend has begun,

...0; spin_unlock_irq(&drm->hpd_lock); @@ -635,7 +638,7 @@ nouveau_display_fini(struct drm_device *dev, bool suspend, bool runtime) } drm_connector_list_iter_end(&conn_iter); - if (!runtime) + if (!runtime && !drm->headless) cancel_work_sync(&drm->hpd_work); drm_kms_helper_poll_disable(dev); @@ -729,6 +732,7 @@ nouveau_display_create(struct drm_device *dev) /* no display hw */ if (ret == -ENODEV) { ret = 0; + drm->headless = true; goto disp_create_err; } diff --git a/drivers/gpu/drm/nouveau/nouveau_drv.h b/drivers/gpu/drm/nouveau/nouveau_drv.h index e239c6...

...ouveau_runtime_pm == 0) return -EINVAL; - /* are we optimus enabled? */ - if (nouveau_runtime_pm == -1 && !nouveau_is_optimus() && !nouveau_is_v1_dsm()) { - DRM_DEBUG_DRIVER("failing to power off - not optimus\n"); - return -EINVAL; - } - nv_debug_level(SILENT); drm_kms_helper_poll_disable(drm_dev); vga_switcheroo_set_dynamic_switch(pdev, VGA_SWITCHEROO_OFF); @@ -951,12 +949,6 @@ static int nouveau_pmops_runtime_idle(struct device *dev) if (nouveau_runtime_pm == 0) return -EBUSY; - /* are we optimus enabled? */ - if (nouveau_runtime_pm == -1 && !nouveau_is_optimus()...

...a/drivers/gpu/drm/qxl/qxl_drv.c > +++ b/drivers/gpu/drm/qxl/qxl_drv.c > @@ -136,20 +136,11 @@ static int qxl_drm_freeze(struct drm_device *dev) > { > struct pci_dev *pdev = dev->pdev; > struct qxl_device *qdev = dev->dev_private; > - struct drm_crtc *crtc; > - > - drm_kms_helper_poll_disable(dev); > - > - console_lock(); > - qxl_fbdev_set_suspend(qdev, 1); > - console_unlock(); > + int ret; > > - /* unpin the front buffers */ > - list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) { > - const struct drm_crtc_helper_funcs *crtc_funcs = crtc-...

This is a trimmed down version of https://patchwork.freedesktop.org/series/46637/ with all of the review comments addressed. The last version of this series had fixes for the i2c and DP aux busses to ensure that the GPU would be turned on whenever anything tried to access the i2c/aux busses. Unfortunately: one of the fixes apparently contained some very incorrect usage of Linux's runtime PM

...); spin_lock_irq(&drm->hpd_lock); @@ -635,7 +643,7 @@ nouveau_display_fini(struct drm_device *dev, bool suspend, bool runtime) } drm_connector_list_iter_end(&conn_iter); - if (!runtime) + if (!runtime && !drm->headless) cancel_work_sync(&drm->hpd_work); drm_kms_helper_poll_disable(dev); @@ -729,6 +737,7 @@ nouveau_display_create(struct drm_device *dev) /* no display hw */ if (ret == -ENODEV) { ret = 0; + drm->headless = true; goto disp_create_err; } diff --git a/drivers/gpu/drm/nouveau/nouveau_drv.h b/drivers/gpu/drm/nouveau/nouveau_drv.h index e239c6...

...@ -635,7 +643,7 @@ nouveau_display_fini(struct drm_device *dev, bool suspend, bool runtime) > } > drm_connector_list_iter_end(&conn_iter); > > - if (!runtime) > + if (!runtime && !drm->headless) > cancel_work_sync(&drm->hpd_work); > > drm_kms_helper_poll_disable(dev); > @@ -729,6 +737,7 @@ nouveau_display_create(struct drm_device *dev) > /* no display hw */ > if (ret == -ENODEV) { > ret = 0; > + drm->headless = true; > goto disp_create_err; > } > > diff --git a/drivers/gpu/drm/nouveau/nouveau_drv.h b...

...race condition in their driver. > +bool drm_kms_helper_is_poll_worker(void) > +{ > + struct work_struct *work = current_work(); > + > + return work && work->func == output_poll_execute; > +} > +EXPORT_SYMBOL(drm_kms_helper_is_poll_worker); > + > /** > * drm_kms_helper_poll_disable - disable output polling > * @dev: drm_device > diff --git a/include/drm/drm_crtc_helper.h b/include/drm/drm_crtc_helper.h > index 76e237bd989b..6914633037a5 100644 > --- a/include/drm/drm_crtc_helper.h > +++ b/include/drm/drm_crtc_helper.h > @@ -77,5 +77,6 @@ void drm_kms_helpe...