similar to: [PATCH v4 0/8] Fix connector probing deadlocks from RPM bugs

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

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()

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()

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)

On Mon, Jul 30, 2018 at 08:39:48PM -0400, Lyude Paul wrote: > 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 >

On Mon, Aug 13, 2018 at 03:16:43PM -0400, Lyude Paul wrote: > I'm sure I don't need to tell you that fb_helper's locking is a mess. Uh, loaded statement :-) Especially since we've just reworked all the fbdev locking to untangle it from drm_modeset locking. What's still a mess about it? It's documented, and very clearly wrapped around all the drm_modeset locks. If

On Wed, Aug 01, 2018 at 05:14:57PM -0400, Lyude Paul wrote: > When we disable hotplugging on the GPU, we need to be able to > synchronize with each connector's hotplug interrupt handler before the > interrupt is finally disabled. This can be a problem however, since > nouveau_connector_detect() currently grabs a runtime power reference > when handling connector probing. This

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

On Wed, Jul 18, 2018 at 04:56:39PM -0400, Lyude Paul wrote: > When DP MST hubs get confused, they can occasionally 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

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

On Wed, Aug 01, 2018 at 05:14:58PM -0400, Lyude Paul wrote: > We can't and don't need to try resuming the device from our hotplug > handlers, but hotplug events are generally something we'd like to keep > the device awake for whenever possible. So, grab a PM ref safely in our > hotplug handlers using pm_runtime_get_noresume() and mark the device as > busy once we're

[cc += linux-pm] Hi Lyude, First of all, thanks a lot for looking into this. On Mon, Jul 16, 2018 at 07:59:25PM -0400, Lyude Paul wrote: > In order to fix all of the spots that need to have runtime PM get/puts() > added, we need to ensure that it's possible for us to call > pm_runtime_get/put() in any context, regardless of how deep, since > almost all of the spots that are

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

On Mon, 2018-08-06 at 10:43 +0200, Daniel Vetter wrote: > On Mon, Jul 30, 2018 at 08:39:48PM -0400, Lyude Paul wrote: > > 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

This fixes some nasty issues I found in nouveau that were being caused looping through connectors using racy legacy methods, along with some caused by making incorrect assumptions about the drm_connector structs in nouveau's connector list. Most of these memory corruption issues could be reproduced by using an MST hub with nouveau. Cc: Karol Herbst <karolherbst at gmail.com> Cc: stable

This fixes some nasty issues I found in nouveau that were being caused looping through connectors using racy legacy methods, along with some caused by making incorrect assumptions about the drm_connector structs in nouveau's connector list. Most of these memory corruption issues could be reproduced by using an MST hub with nouveau. Next version of

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

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

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,