search for: crtc_ww_class_acquir

...90 bus_add_driver+0x164/0x260 driver_register+0x57/0xc0 do_one_initcall+0x4d/0x323 do_init_module+0x5b/0x1f8 load_module+0x20e5/0x2ac0 __do_sys_finit_module+0xb7/0xd0 do_syscall_64+0x60/0x1b0 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #2 (crtc_ww_class_acquire){+.+.}: drm_helper_probe_single_connector_modes+0x58/0x6b0 [drm_kms_helper] drm_setup_crtcs+0x15e/0xc90 [drm_kms_helper] __drm_fb_helper_initial_config_and_unlock+0x29/0x480 [drm_kms_helper] nouveau_fbcon_init+0x138/0x1a0 [nouveau] nouveau_drm_load+0x173/0x7e0 [n...

.../dma-resv.h:247 suspicious rcu_dereference_protected() usage! [ 37.708899] [ 37.708899] other info that might help us debug this: [ 37.708899] [ 37.709856] [ 37.709856] rcu_scheduler_active = 2, debug_locks = 1 [ 37.710771] 3 locks held by Xorg/1869: [ 37.711266] #0: ffff8880a976fa48 (crtc_ww_class_acquire){+.+.}, at: drm_mode_cursor_common (linux/drivers/gpu/drm/drm_plane.c:949) [ 37.712372] #1: ffff8880b32e00a8 (crtc_ww_class_mutex){+.+.}, at: drm_modeset_lock (linux/drivers/gpu/drm/drm_modeset_lock.c:258 linux/drivers/gpu/drm/drm_modeset_lock.c:342 linux/drivers/gpu/drm/drm_modeset_lock.c:338)...

...3582] #2: 000000006e013cbe (&dev->mode_config.mutex){+.+.}, at: drm_helper_hpd_irq_event+0x6c/0x120 [drm_kms_helper] > [ 861.554357] #3: 000000004afc5de1 (drm_connector_list_iter){.+.+}, at: drm_helper_hpd_irq_event+0x78/0x120 [drm_kms_helper] > [ 861.555227] #4: 0000000044f294d9 (crtc_ww_class_acquire){+.+.}, at: drm_helper_probe_detect_ctx+0x3d/0x100 [drm_kms_helper] > [ 861.556133] #5: 00000000db193642 (crtc_ww_class_mutex){+.+.}, at: drm_modeset_lock+0x4b/0x130 [drm] > > [ 861.557864] ============================================= > > [ 861.559507] NMI backtrace for cpu 2...

...0x620 [ 246.767390] #1: 00000000bb59b134 ((work_completion)(&mgr->work)){+.+.}, at: process_one_work+0x1b3/0x620 [ 246.768154] #2: 00000000cb66735f (&helper->lock){+.+.}, at: drm_fb_helper_restore_fbdev_mode_unlocked+0x4c/0xb0 [drm_kms_helper] [ 246.768966] #3: 000000004c8f0b6b (crtc_ww_class_acquire){+.+.}, at: restore_fbdev_mode_atomic+0x4b/0x240 [drm_kms_helper] [ 246.769921] #4: 000000004c34a296 (crtc_ww_class_mutex){+.+.}, at: drm_modeset_backoff+0x8a/0x1b0 [drm] [ 246.770839] 1 lock held by dmesg/1038: [ 246.771739] 2 locks held by zsh/1172: [ 246.772650] #0: 00000000836d0438 (&amp...

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()

...46.767390] #1: 00000000bb59b134 ((work_completion)(&mgr->work)){+.+.}, at: process_one_work+0x1b3/0x620 > [ 246.768154] #2: 00000000cb66735f (&helper->lock){+.+.}, at: drm_fb_helper_restore_fbdev_mode_unlocked+0x4c/0xb0 [drm_kms_helper] > [ 246.768966] #3: 000000004c8f0b6b (crtc_ww_class_acquire){+.+.}, at: restore_fbdev_mode_atomic+0x4b/0x240 [drm_kms_helper] > [ 246.769921] #4: 000000004c34a296 (crtc_ww_class_mutex){+.+.}, at: drm_modeset_backoff+0x8a/0x1b0 [drm] > [ 246.770839] 1 lock held by dmesg/1038: > [ 246.771739] 2 locks held by zsh/1172: > [ 246.772650] #0: 00...

...[ 861.553582] #2: 000000006e013cbe (&dev->mode_config.mutex){+.+.}, at: drm_helper_hpd_irq_event+0x6c/0x120 [drm_kms_helper] [ 861.554357] #3: 000000004afc5de1 (drm_connector_list_iter){.+.+}, at: drm_helper_hpd_irq_event+0x78/0x120 [drm_kms_helper] [ 861.555227] #4: 0000000044f294d9 (crtc_ww_class_acquire){+.+.}, at: drm_helper_probe_detect_ctx+0x3d/0x100 [drm_kms_helper] [ 861.556133] #5: 00000000db193642 (crtc_ww_class_mutex){+.+.}, at: drm_modeset_lock+0x4b/0x130 [drm] [ 861.557864] ============================================= [ 861.559507] NMI backtrace for cpu 2 [ 861.560363] CPU: 2 PI...

...0x620 [ 246.767390] #1: 00000000bb59b134 ((work_completion)(&mgr->work)){+.+.}, at: process_one_work+0x1b3/0x620 [ 246.768154] #2: 00000000cb66735f (&helper->lock){+.+.}, at: drm_fb_helper_restore_fbdev_mode_unlocked+0x4c/0xb0 [drm_kms_helper] [ 246.768966] #3: 000000004c8f0b6b (crtc_ww_class_acquire){+.+.}, at: restore_fbdev_mode_atomic+0x4b/0x240 [drm_kms_helper] [ 246.769921] #4: 000000004c34a296 (crtc_ww_class_mutex){+.+.}, at: drm_modeset_backoff+0x8a/0x1b0 [drm] [ 246.770839] 1 lock held by dmesg/1038: [ 246.771739] 2 locks held by zsh/1172: [ 246.772650] #0: 00000000836d0438 (&amp...

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

...things are a bit more complicated. As I've learned the hard way, we can grab &mgr->lock.base for everything except for port->connector. See, our normal driver probing paths end up generating this rather obvious lockdep chain: &drm->mode_config.mutex -> crtc_ww_class_mutex/crtc_ww_class_acquire -> &connector->mutex However, sysfs grabs &drm->mode_config.mutex in order to protect itself from connector state changing under it. Because this entails grabbing kn->count, e.g. the lock that the kernel provides for protecting sysfs contexts, we end up grabbing kn->cou...

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)

...46.767390] #1: 00000000bb59b134 ((work_completion)(&mgr->work)){+.+.}, at: process_one_work+0x1b3/0x620 > [ 246.768154] #2: 00000000cb66735f (&helper->lock){+.+.}, at: drm_fb_helper_restore_fbdev_mode_unlocked+0x4c/0xb0 [drm_kms_helper] > [ 246.768966] #3: 000000004c8f0b6b (crtc_ww_class_acquire){+.+.}, at: restore_fbdev_mode_atomic+0x4b/0x240 [drm_kms_helper] > [ 246.769921] #4: 000000004c34a296 (crtc_ww_class_mutex){+.+.}, at: drm_modeset_backoff+0x8a/0x1b0 [drm] > [ 246.770839] 1 lock held by dmesg/1038: > [ 246.771739] 2 locks held by zsh/1172: > [ 246.772650] #0: 00...

...46.767390] #1: 00000000bb59b134 ((work_completion)(&mgr->work)){+.+.}, at: process_one_work+0x1b3/0x620 > [ 246.768154] #2: 00000000cb66735f (&helper->lock){+.+.}, at: drm_fb_helper_restore_fbdev_mode_unlocked+0x4c/0xb0 [drm_kms_helper] > [ 246.768966] #3: 000000004c8f0b6b (crtc_ww_class_acquire){+.+.}, at: restore_fbdev_mode_atomic+0x4b/0x240 [drm_kms_helper] > [ 246.769921] #4: 000000004c34a296 (crtc_ww_class_mutex){+.+.}, at: drm_modeset_backoff+0x8a/0x1b0 [drm] > [ 246.770839] 1 lock held by dmesg/1038: > [ 246.771739] 2 locks held by zsh/1172: > [ 246.772650] #0: 00...

...0x620 [ 246.767390] #1: 00000000bb59b134 ((work_completion)(&mgr->work)){+.+.}, at: process_one_work+0x1b3/0x620 [ 246.768154] #2: 00000000cb66735f (&helper->lock){+.+.}, at: drm_fb_helper_restore_fbdev_mode_unlocked+0x4c/0xb0 [drm_kms_helper] [ 246.768966] #3: 000000004c8f0b6b (crtc_ww_class_acquire){+.+.}, at: restore_fbdev_mode_atomic+0x4b/0x240 [drm_kms_helper] [ 246.769921] #4: 000000004c34a296 (crtc_ww_class_mutex){+.+.}, at: drm_modeset_backoff+0x8a/0x1b0 [drm] [ 246.770839] 1 lock held by dmesg/1038: [ 246.771739] 2 locks held by zsh/1172: [ 246.772650] #0: 00000000836d0438 (&amp...

...0x620 [ 246.767390] #1: 00000000bb59b134 ((work_completion)(&mgr->work)){+.+.}, at: process_one_work+0x1b3/0x620 [ 246.768154] #2: 00000000cb66735f (&helper->lock){+.+.}, at: drm_fb_helper_restore_fbdev_mode_unlocked+0x4c/0xb0 [drm_kms_helper] [ 246.768966] #3: 000000004c8f0b6b (crtc_ww_class_acquire){+.+.}, at: restore_fbdev_mode_atomic+0x4b/0x240 [drm_kms_helper] [ 246.769921] #4: 000000004c34a296 (crtc_ww_class_mutex){+.+.}, at: drm_modeset_backoff+0x8a/0x1b0 [drm] [ 246.770839] 1 lock held by dmesg/1038: [ 246.771739] 2 locks held by zsh/1172: [ 246.772650] #0: 00000000836d0438 (&amp...

...0x620 [ 246.767390] #1: 00000000bb59b134 ((work_completion)(&mgr->work)){+.+.}, at: process_one_work+0x1b3/0x620 [ 246.768154] #2: 00000000cb66735f (&helper->lock){+.+.}, at: drm_fb_helper_restore_fbdev_mode_unlocked+0x4c/0xb0 [drm_kms_helper] [ 246.768966] #3: 000000004c8f0b6b (crtc_ww_class_acquire){+.+.}, at: restore_fbdev_mode_atomic+0x4b/0x240 [drm_kms_helper] [ 246.769921] #4: 000000004c34a296 (crtc_ww_class_mutex){+.+.}, at: drm_modeset_backoff+0x8a/0x1b0 [drm] [ 246.770839] 1 lock held by dmesg/1038: [ 246.771739] 2 locks held by zsh/1172: [ 246.772650] #0: 00000000836d0438 (&amp...

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

...4 ((work_completion)(&mgr- > > >work)){+.+.}, at: process_one_work+0x1b3/0x620 > > [ 246.768154] #2: 00000000cb66735f (&helper->lock){+.+.}, at: > > drm_fb_helper_restore_fbdev_mode_unlocked+0x4c/0xb0 [drm_kms_helper] > > [ 246.768966] #3: 000000004c8f0b6b (crtc_ww_class_acquire){+.+.}, at: > > restore_fbdev_mode_atomic+0x4b/0x240 [drm_kms_helper] > > [ 246.769921] #4: 000000004c34a296 (crtc_ww_class_mutex){+.+.}, at: > > drm_modeset_backoff+0x8a/0x1b0 [drm] > > [ 246.770839] 1 lock held by dmesg/1038: > > [ 246.771739] 2 locks held by zs...

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

...4 ((work_completion)(&mgr- > > >work)){+.+.}, at: process_one_work+0x1b3/0x620 > > [ 246.768154] #2: 00000000cb66735f (&helper->lock){+.+.}, at: > > drm_fb_helper_restore_fbdev_mode_unlocked+0x4c/0xb0 [drm_kms_helper] > > [ 246.768966] #3: 000000004c8f0b6b (crtc_ww_class_acquire){+.+.}, at: > > restore_fbdev_mode_atomic+0x4b/0x240 [drm_kms_helper] > > [ 246.769921] #4: 000000004c34a296 (crtc_ww_class_mutex){+.+.}, at: > > drm_modeset_backoff+0x8a/0x1b0 [drm] > > [ 246.770839] 1 lock held by dmesg/1038: > > [ 246.771739] 2 locks held by zs...