search for: drm_fb_helper_output_poll_changed

...ionally stop responding for a good bit of time up until the point where the DRM driver manages to do the right DPCD accesses to get it to start responding again. In a worst case scenario however, this process can take upwards of 10+ seconds. Currently we use the default output_poll_changed handler drm_fb_helper_output_poll_changed() to handle output polling, which doesn't happen to grab any power references on the device when polling. If we're unlucky enough to have a hub (such as Lenovo's infamous laptop docks for the P5x/P7x series) that's easily startled and confused, this can lead to a pretty nasty deadlo...

...good bit of time up until the point where the DRM driver manages to > do the right DPCD accesses to get it to start responding again. In a > worst case scenario however, this process can take upwards of 10+ > seconds. > > Currently we use the default output_poll_changed handler > drm_fb_helper_output_poll_changed() to handle output polling, which > doesn't happen to grab any power references on the device when polling. > If we're unlucky enough to have a hub (such as Lenovo's infamous laptop > docks for the P5x/P7x series) that's easily startled and confused, this > can lead to a...

...efore anyhow. So: this just contains the seriously important fixes that will stop people's machines from crashing very hard. Hopefully I can come up with a solution to the i2c/aux problem soon after fixing some other glaring MST bugs nouveau currently has. Lyude Paul (2): drm/fb_helper: Add drm_fb_helper_output_poll_changed_with_rpm() drm/probe_helper: Add drm_helper_probe_single_connector_modes_with_rpm() drivers/gpu/drm/drm_fb_helper.c | 23 +++++++++++++++ drivers/gpu/drm/drm_probe_helper.c | 31 +++++++++++++++++++++ drivers/gpu/drm/nouveau/dispnv50/disp.c | 4 +-- drivers/gpu/drm...

...point where the DRM driver manages to > > do the right DPCD accesses to get it to start responding again. In a > > worst case scenario however, this process can take upwards of 10+ > > seconds. > > > > Currently we use the default output_poll_changed handler > > drm_fb_helper_output_poll_changed() to handle output polling, which > > doesn't happen to grab any power references on the device when polling. > > If we're unlucky enough to have a hub (such as Lenovo's infamous laptop > > docks for the P5x/P7x series) that's easily startled and confused, this &gt...

...ionally stop responding for a good bit of time up until the point where the DRM driver manages to do the right DPCD accesses to get it to start responding again. In a worst case scenario however, this process can take upwards of 10+ seconds. Currently we use the default output_poll_changed handler drm_fb_helper_output_poll_changed() to handle output polling, which doesn't happen to grab any power references on the device when polling. If we're unlucky enough to have a hub (such as Lenovo's infamous laptop docks for the P5x/P7x series) that's easily startled and confused, this can lead to a pretty nasty deadlo...

...ages to > > > do the right DPCD accesses to get it to start responding again. In a > > > worst case scenario however, this process can take upwards of 10+ > > > seconds. > > > > > > Currently we use the default output_poll_changed handler > > > drm_fb_helper_output_poll_changed() to handle output polling, which > > > doesn't happen to grab any power references on the device when polling. > > > If we're unlucky enough to have a hub (such as Lenovo's infamous laptop > > > docks for the P5x/P7x series) that's easily startled and con...

...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. > [ 246.673398] Not tainted 4.18.0-rc5Lyude-Test+ #2 > [ 246....

...cking 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 like nouveau tries to use rpm as the outermost lock, surrounding ev...

...u 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 4.18.0-rc5Lyude-Test+ #2 [ 246.675271] "echo 0 > /pro...

...u 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 4.18.0-rc5Lyude-Test+ #2 [ 246.675271] "echo 0 > /pro...

...u 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 4.18.0-rc5Lyude-Test+ #2 [ 246.675271] "echo 0 > /pro...

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

...; 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 like nouveau tries to use rpm as the outer...

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()

...me_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_changed = nouveau_output_poll_changed, It might make sense to provide a generic DRM helper for this. Same for patch 3 in this series. Thanks, Lukas

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

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

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 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 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()