search for: drm_fb_helper_hotplug_event

...m sure I don't need to tell you that fb_helper's locking is a mess. > That being said; fb_helper's locking mess can seriously complicate the > runtime suspend/resume operations of drivers because it can invoke > atomic commits and connector probing from anywhere that calls > drm_fb_helper_hotplug_event(). Since most drivers use > drm_fb_helper_output_poll_changed() as their output_poll_changed > handler, this can happen in every single context that can fire off a > hotplug event. An example: Uh, I think this ever more looks like a serious rabbit hole between nouveau and rpm. It looks li...

I'm sure I don't need to tell you that fb_helper's locking is a mess. That being said; fb_helper's locking mess can seriously complicate the runtime suspend/resume operations of drivers because it can invoke atomic commits and connector probing from anywhere that calls drm_fb_helper_hotplug_event(). Since most drivers use drm_fb_helper_output_poll_changed() as their output_poll_changed handler, this can happen in every single context that can fire off a hotplug event. An example: [ 246.669625] INFO: task kworker/4:0:37 blocked for more than 120 seconds. [ 246.673398] Not tainted 4....

...ound all the drm_modeset locks. If there's gaps, please bring them up. > That being said; fb_helper's locking mess can seriously complicate the > runtime suspend/resume operations of drivers because it can invoke > atomic commits and connector probing from anywhere that calls > drm_fb_helper_hotplug_event(). Since most drivers use > drm_fb_helper_output_poll_changed() as their output_poll_changed > handler, this can happen in every single context that can fire off a > hotplug event. An example: > > [ 246.669625] INFO: task kworker/4:0:37 blocked for more than 120 seconds. > [ 24...

I'm sure I don't need to tell you that fb_helper's locking is a mess. That being said; fb_helper's locking mess can seriously complicate the runtime suspend/resume operations of drivers because it can invoke atomic commits and connector probing from anywhere that calls drm_fb_helper_hotplug_event(). Since most drivers use drm_fb_helper_output_poll_changed() as their output_poll_changed handler, this can happen in every single context that can fire off a hotplug event. An example: [ 246.669625] INFO: task kworker/4:0:37 blocked for more than 120 seconds. [ 246.673398] Not tainted 4....

...eed to tell you that fb_helper's locking is a mess. > > That being said; fb_helper's locking mess can seriously complicate the > > runtime suspend/resume operations of drivers because it can invoke > > atomic commits and connector probing from anywhere that calls > > drm_fb_helper_hotplug_event(). Since most drivers use > > drm_fb_helper_output_poll_changed() as their output_poll_changed > > handler, this can happen in every single context that can fire off a > > hotplug event. An example: > > Uh, I think this ever more looks like a serious rabbit hole between &gt...

I'm sure I don't need to tell you that fb_helper's locking is a mess. That being said; fb_helper's locking mess can seriously complicate the runtime suspend/resume operations of drivers because it can invoke atomic commits and connector probing from anywhere that calls drm_fb_helper_hotplug_event(). Since most drivers use drm_fb_helper_output_poll_changed() as their output_poll_changed handler, this can happen in every single context that can fire off a hotplug event. An example: [ 246.669625] INFO: task kworker/4:0:37 blocked for more than 120 seconds. [ 246.673398] Not tainted 4....

Latest version of https://patchwork.freedesktop.org/series/46815/ , with one small change re: ilia Lyude Paul (5): drm/nouveau: Fix bogus drm_kms_helper_poll_enable() placement drm/nouveau: Remove duplicate poll_enable() in pmops_runtime_suspend() drm/nouveau: Fix deadlock with fb_helper with async RPM requests drm/nouveau: Use pm_runtime_get_noresume() in connector_detect()

...s output_poll_execute [drm_kms_helper] [ 246.678704] Call Trace: [ 246.679753] __schedule+0x322/0xaf0 [ 246.680916] schedule+0x33/0x90 [ 246.681924] schedule_preempt_disabled+0x15/0x20 [ 246.683023] __mutex_lock+0x569/0x9a0 [ 246.684035] ? kobject_uevent_env+0x117/0x7b0 [ 246.685132] ? drm_fb_helper_hotplug_event.part.28+0x20/0xb0 [drm_kms_helper] [ 246.686179] mutex_lock_nested+0x1b/0x20 [ 246.687278] ? mutex_lock_nested+0x1b/0x20 [ 246.688307] drm_fb_helper_hotplug_event.part.28+0x20/0xb0 [drm_kms_helper] [ 246.689420] drm_fb_helper_output_poll_changed+0x23/0x30 [drm_kms_helper] [ 246.690462] dr...

This is the next version of https://patchwork.freedesktop.org/series/46815/ With a lot more thought put into it so as to avoid the potential deadlock scenarios I missed. This also required fixing some bogus DRM helper usage. Try and deadlock me now, nouveau. I dare you!!! Lyude Paul (8): drm/nouveau: Fix bogus drm_kms_helper_poll_enable() placement drm/nouveau: Enable polling even if we

...s output_poll_execute [drm_kms_helper] [ 246.678704] Call Trace: [ 246.679753] __schedule+0x322/0xaf0 [ 246.680916] schedule+0x33/0x90 [ 246.681924] schedule_preempt_disabled+0x15/0x20 [ 246.683023] __mutex_lock+0x569/0x9a0 [ 246.684035] ? kobject_uevent_env+0x117/0x7b0 [ 246.685132] ? drm_fb_helper_hotplug_event.part.28+0x20/0xb0 [drm_kms_helper] [ 246.686179] mutex_lock_nested+0x1b/0x20 [ 246.687278] ? mutex_lock_nested+0x1b/0x20 [ 246.688307] drm_fb_helper_hotplug_event.part.28+0x20/0xb0 [drm_kms_helper] [ 246.689420] drm_fb_helper_output_poll_changed+0x23/0x30 [drm_kms_helper] [ 246.690462] dr...

...er] > [ 246.678704] Call Trace: > [ 246.679753] __schedule+0x322/0xaf0 > [ 246.680916] schedule+0x33/0x90 > [ 246.681924] schedule_preempt_disabled+0x15/0x20 > [ 246.683023] __mutex_lock+0x569/0x9a0 > [ 246.684035] ? kobject_uevent_env+0x117/0x7b0 > [ 246.685132] ? drm_fb_helper_hotplug_event.part.28+0x20/0xb0 [drm_kms_helper] > [ 246.686179] mutex_lock_nested+0x1b/0x20 > [ 246.687278] ? mutex_lock_nested+0x1b/0x20 > [ 246.688307] drm_fb_helper_hotplug_event.part.28+0x20/0xb0 [drm_kms_helper] > [ 246.689420] drm_fb_helper_output_poll_changed+0x23/0x30 [drm_kms_helper...

Latest version of https://patchwork.freedesktop.org/series/46815/ with some significant improvements: - I finally figured out a clean way to do this entirely with runtime PM helpers, no avoiding grabbing refs required! - Since this new method removes the need for a lot of the other changes I made (although we probably still want those changes, but not for fixing these deadlocks)

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

...race: > > [ 246.679753] __schedule+0x322/0xaf0 > > [ 246.680916] schedule+0x33/0x90 > > [ 246.681924] schedule_preempt_disabled+0x15/0x20 > > [ 246.683023] __mutex_lock+0x569/0x9a0 > > [ 246.684035] ? kobject_uevent_env+0x117/0x7b0 > > [ 246.685132] ? drm_fb_helper_hotplug_event.part.28+0x20/0xb0 > > [drm_kms_helper] > > [ 246.686179] mutex_lock_nested+0x1b/0x20 > > [ 246.687278] ? mutex_lock_nested+0x1b/0x20 > > [ 246.688307] drm_fb_helper_hotplug_event.part.28+0x20/0xb0 > > [drm_kms_helper] > > [ 246.689420] drm_fb_helper_outpu...

Next version of https://patchwork.freedesktop.org/series/46815/ Same as previous version, but some small changes made to commit messages and acks/rbs have been added Lyude Paul (5): drm/nouveau: Fix bogus drm_kms_helper_poll_enable() placement drm/nouveau: Remove duplicate poll_enable() in pmops_runtime_suspend() drm/nouveau: Fix deadlock with fb_helper with async RPM requests

...ers/gpu/drm/nouveau/dispnv50/disp.c > @@ -2012,10 +2012,18 @@ nv50_disp_atomic_state_alloc(struct drm_device *dev) > return &atom->state; > } > > +static void > +nouveau_output_poll_changed(struct drm_device *dev) > +{ > + pm_runtime_get_sync(dev->dev); > + drm_fb_helper_hotplug_event(dev->fb_helper); > + pm_runtime_put_autosuspend(dev->dev); > +} > + > static const struct drm_mode_config_funcs > nv50_disp_func = { > .fb_create = nouveau_user_framebuffer_create, > - .output_poll_changed = drm_fb_helper_output_poll_changed, > + .output_poll_chang...

This is the latest version of https://patchwork.freedesktop.org/series/46815/ With a bunch of fixes to the new fb_helper to prevent it from breaking module loading/unloading with nouveau. Also; lots of documentation fixes and one fix in response to a kbuild bot. Lyude Paul (8): drm/nouveau: Fix bogus drm_kms_helper_poll_enable() placement drm/nouveau: Enable polling even if we have runtime

This fixes quite a number of runtime PM bugs I found that have been causing some pretty nasty issues such as: - Deadlocking on boot - Connector probing potentially not working while the GPU is in runtime suspend - i2c char dev not working while the GPU is in runtime suspend - aux char dev not working while the GPU is in runtime suspend There's definitely more parts of nouveau that need

This is the latest version of https://patchwork.freedesktop.org/series/46815/ I moved everything out of fb_helper and back into nouveau, because it seems that other drivers actually do have this handled already as far as I can tell. Lyude Paul (13): drm/nouveau: Fix bogus drm_kms_helper_poll_enable() placement drm/nouveau: Remove duplicate poll_enable() in pmops_runtime_suspend()

...callback+0xb6/0x1e0 > [ 12.768423] ? kobject_uevent_env+0x111/0x5e0 > [ 12.768425] ? pci_pm_runtime_resume+0xa0/0xa0 > [ 12.768427] ? rpm_callback+0x1f/0x70 > [ 12.768429] ? pci_pm_runtime_resume+0xa0/0xa0 > [ 12.768431] ? rpm_suspend+0x11f/0x640 > [ 12.768441] ? drm_fb_helper_hotplug_event+0x9a/0xe0 [drm_kms_helper] > [ 12.768447] ? output_poll_execute+0x17b/0x1a0 [drm_kms_helper] > [ 12.768449] ? pm_runtime_work+0x64/0xa0 > [ 12.768453] ? process_one_work+0x1db/0x410 > [ 12.768456] ? worker_thread+0x47/0x3d0 > [ 12.768459] ? process_one_work+0x410/0x410...