From 8218c3f4df3bb1c637c17552405039a6dd3c1ee1 Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Fri, 27 Feb 2015 12:58:13 +0100 Subject: drm: Fixup racy refcounting in plane_force_disable Originally it was impossible to be dropping the last refcount in this function since there was always one around still from the idr. But in commit 83f45fc360c8e16a330474860ebda872d1384c8c Author: Daniel Vetter Date: Wed Aug 6 09:10:18 2014 +0200 drm: Don't grab an fb reference for the idr we've switched to weak references, broke that assumption but forgot to fix it up. Since we still force-disable planes it's only possible to hit this when racing multiple rmfb with fbdev restoring or similar evil things. As long as userspace is nice it's impossible to hit the BUG_ON. But the BUG_ON would most likely be hit from fbdev code, which usually invovles the console_lock besides all modeset locks. So very likely we'd never get the bug reports if this was hit in the wild, hence better be safe than sorry and backport. Spotted by Matt Roper while reviewing other patches. [airlied: pull this back into 4.0 - the oops happens there] Cc: stable@vger.kernel.org Cc: Matt Roper Reviewed-by: Matt Roper Signed-off-by: Daniel Vetter Signed-off-by: Dave Airlie --- drivers/gpu/drm/drm_crtc.c | 13 +------------ 1 file changed, 1 insertion(+), 12 deletions(-) (limited to 'drivers') diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c index f6d04c7b5115..679b10e34fb5 100644 --- a/drivers/gpu/drm/drm_crtc.c +++ b/drivers/gpu/drm/drm_crtc.c @@ -525,17 +525,6 @@ void drm_framebuffer_reference(struct drm_framebuffer *fb) } EXPORT_SYMBOL(drm_framebuffer_reference); -static void drm_framebuffer_free_bug(struct kref *kref) -{ - BUG(); -} - -static void __drm_framebuffer_unreference(struct drm_framebuffer *fb) -{ - DRM_DEBUG("%p: FB ID: %d (%d)\n", fb, fb->base.id, atomic_read(&fb->refcount.refcount)); - kref_put(&fb->refcount, drm_framebuffer_free_bug); -} - /** * drm_framebuffer_unregister_private - unregister a private fb from the lookup idr * @fb: fb to unregister @@ -1320,7 +1309,7 @@ void drm_plane_force_disable(struct drm_plane *plane) return; } /* disconnect the plane from the fb and crtc: */ - __drm_framebuffer_unreference(plane->old_fb); + drm_framebuffer_unreference(plane->old_fb); plane->old_fb = NULL; plane->fb = NULL; plane->crtc = NULL; -- cgit v1.2.3 From 59a58cb34d3fe73e6c899cc5d9a87428ca662925 Mon Sep 17 00:00:00 2001 From: Damien Lespiau Date: Thu, 5 Feb 2015 18:30:20 +0000 Subject: drm/i915: Don't try to reference the fb in get_initial_plane_config() Tvrtko noticed a new warning on boot: WARNING: CPU: 1 PID: 353 at include/linux/kref.h:47 drm_framebuffer_reference+0x6c/0x80 [drm]() Call Trace: [] dump_stack+0x4f/0x7b [] warn_slowpath_common+0xaa/0xd0 [] warn_slowpath_null+0x1a/0x20 [] drm_framebuffer_reference+0x6c/0x80 [drm] [] update_state_fb.isra.54+0x47/0x50 [i915] [] skylake_get_initial_plane_config+0x93c/0x950 [i915] [] intel_modeset_init+0x1551/0x17c0 [i915] [] i915_driver_load+0xed0/0x11e0 [i915] [] ? _raw_spin_unlock_irqrestore+0x51/0x70 [] drm_dev_register+0x77/0x110 [drm] [] drm_get_pci_dev+0x11b/0x1f0 [drm] [] ? trace_hardirqs_on+0xd/0x10 [] ? _raw_spin_unlock_irqrestore+0x51/0x70 [] i915_pci_probe+0x56/0x60 [i915] [] pci_device_probe+0x7c/0x100 [] driver_probe_device+0x16d/0x380 We cannot take a reference at this point, not before intel_framebuffer_init() and the underlying drm_framebuffer_init(). Introduced in: commit 706dc7b549175e47f23e913b7f1e52874a7d0f56 Author: Matt Roper Date: Tue Feb 3 13:10:04 2015 -0800 drm/i915: Ensure plane->state->fb stays in sync with plane->fb v2: Don't move update_state_fb(). It was moved around because I originally put update_state_fb() in intel_alloc_plane_obj() before finding a better place. (Matt) Reviewed-by: Matt Roper Reported-by: Tvrtko Ursulin Cc: Matt Roper Cc: Tvrtko Ursulin Signed-off-by: Damien Lespiau Signed-off-by: Daniel Vetter From drm-next: (cherry picked from commit f55548b5af87ebfc586ca75748947f1c1b1a4a52) Signed-off-by: Dave Airlie --- drivers/gpu/drm/i915/intel_display.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) (limited to 'drivers') diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 6d22128d97b1..1c12262029fb 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -2438,8 +2438,10 @@ intel_find_plane_obj(struct intel_crtc *intel_crtc, if (!intel_crtc->base.primary->fb) return; - if (intel_alloc_plane_obj(intel_crtc, plane_config)) + if (intel_alloc_plane_obj(intel_crtc, plane_config)) { + update_state_fb(intel_crtc->base.primary); return; + } kfree(intel_crtc->base.primary->fb); intel_crtc->base.primary->fb = NULL; @@ -6663,7 +6665,6 @@ i9xx_get_initial_plane_config(struct intel_crtc *crtc, plane_config->size); crtc->base.primary->fb = fb; - update_state_fb(crtc->base.primary); } static void chv_crtc_clock_get(struct intel_crtc *crtc, @@ -7704,7 +7705,6 @@ skylake_get_initial_plane_config(struct intel_crtc *crtc, plane_config->size); crtc->base.primary->fb = fb; - update_state_fb(crtc->base.primary); return; error: @@ -7798,7 +7798,6 @@ ironlake_get_initial_plane_config(struct intel_crtc *crtc, plane_config->size); crtc->base.primary->fb = fb; - update_state_fb(crtc->base.primary); } static bool ironlake_get_pipe_config(struct intel_crtc *crtc, -- cgit v1.2.3 From 832a3aad1e2927b1684e7369c9f36a370e0b95da Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Wed, 18 Mar 2015 18:19:22 +0000 Subject: drm/i915: Keep ring->active_list and ring->requests_list consistent If we retire requests last, we may use a later seqno and so clear the requests lists without clearing the active list, leading to confusion. Hence we should retire requests first for consistency with the early return. The order used to be important as the lifecycle for the object on the active list was determined by request->seqno. However, the requests themselves are now reference counted removing the constraint from the order of retirement. Fixes regression from commit 1b5a433a4dd967b125131da42b89b5cc0d5b1f57 Author: John Harrison Date: Mon Nov 24 18:49:42 2014 +0000 drm/i915: Convert 'i915_seqno_passed' calls into 'i915_gem_request_completed ' and a WARNING: CPU: 0 PID: 1383 at drivers/gpu/drm/i915/i915_gem_evict.c:279 i915_gem_evict_vm+0x10c/0x140() WARN_ON(!list_empty(&vm->active_list)) Identified by updating WATCH_LISTS: [drm:i915_verify_lists] *ERROR* blitter ring: active list not empty, but no requests WARNING: CPU: 0 PID: 681 at drivers/gpu/drm/i915/i915_gem.c:2751 i915_gem_retire_requests_ring+0x149/0x230() WARN_ON(i915_verify_lists(ring->dev)) Note that this is only a problem in evict_vm where the following happens after a retire_request has cleaned out all requests, but not all active bo: - intel_ring_idle called from i915_gpu_idle notices that no requests are outstanding and immediately returns. - i915_gem_retire_requests_ring called from i915_gem_retire_requests also immediately returns when there's no request, still leaving the bo on the active list. - evict_vm hits the WARN_ON(!list_empty(&vm->active_list)) after evicting all active objects that there's still stuff left that shouldn't be there. Signed-off-by: Chris Wilson Cc: John Harrison Cc: Daniel Vetter Reviewed-by: Daniel Vetter Signed-off-by: Jani Nikula --- drivers/gpu/drm/i915/i915_gem.c | 38 +++++++++++++++++++++----------------- 1 file changed, 21 insertions(+), 17 deletions(-) (limited to 'drivers') diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 5b205863b659..27ea6bdebce7 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -2737,24 +2737,11 @@ i915_gem_retire_requests_ring(struct intel_engine_cs *ring) WARN_ON(i915_verify_lists(ring->dev)); - /* Move any buffers on the active list that are no longer referenced - * by the ringbuffer to the flushing/inactive lists as appropriate, - * before we free the context associated with the requests. + /* Retire requests first as we use it above for the early return. + * If we retire requests last, we may use a later seqno and so clear + * the requests lists without clearing the active list, leading to + * confusion. */ - while (!list_empty(&ring->active_list)) { - struct drm_i915_gem_object *obj; - - obj = list_first_entry(&ring->active_list, - struct drm_i915_gem_object, - ring_list); - - if (!i915_gem_request_completed(obj->last_read_req, true)) - break; - - i915_gem_object_move_to_inactive(obj); - } - - while (!list_empty(&ring->request_list)) { struct drm_i915_gem_request *request; struct intel_ringbuffer *ringbuf; @@ -2789,6 +2776,23 @@ i915_gem_retire_requests_ring(struct intel_engine_cs *ring) i915_gem_free_request(request); } + /* Move any buffers on the active list that are no longer referenced + * by the ringbuffer to the flushing/inactive lists as appropriate, + * before we free the context associated with the requests. + */ + while (!list_empty(&ring->active_list)) { + struct drm_i915_gem_object *obj; + + obj = list_first_entry(&ring->active_list, + struct drm_i915_gem_object, + ring_list); + + if (!i915_gem_request_completed(obj->last_read_req, true)) + break; + + i915_gem_object_move_to_inactive(obj); + } + if (unlikely(ring->trace_irq_req && i915_gem_request_completed(ring->trace_irq_req, true))) { ring->irq_put(ring); -- cgit v1.2.3 From 3164a803416832d61268b758112e8dfd7e35cdf7 Mon Sep 17 00:00:00 2001 From: Damien Lespiau Date: Thu, 5 Feb 2015 19:24:25 +0000 Subject: drm/i915: Fix atomic state when reusing the firmware fb Right now, we get a warning when taking over the firmware fb: [drm:drm_atomic_plane_check] FB set but no CRTC with the following backtrace: [] drm_atomic_check_only+0x35d/0x510 [drm] [] drm_atomic_commit+0x17/0x60 [drm] [] drm_atomic_helper_plane_set_property+0x8d/0xd0 [drm_kms_helper] [] drm_mode_plane_set_obj_prop+0x2d/0x90 [drm] [] restore_fbdev_mode+0x6b/0xf0 [drm_kms_helper] [] drm_fb_helper_restore_fbdev_mode_unlocked+0x29/0x80 [drm_kms_helper] [] drm_fb_helper_set_par+0x22/0x50 [drm_kms_helper] [] intel_fbdev_set_par+0x1a/0x60 [i915] [] fbcon_init+0x4f4/0x580 That's because we update the plane state with the fb from the firmware, but we never associate the plane to that CRTC. We don't quite have the full DRM take over from HW state just yet, so fake enough of the plane atomic state to pass the checks. v2: Fix the state on which we set the CRTC in the case we're sharing the initial fb with another pipe. (Matt) Signed-off-by: Damien Lespiau Reviewed-by: Matt Roper Signed-off-by: Daniel Vetter [Jani: backported to drm-intel-fixes for v4.0-rc] Reference: http://mid.gmane.org/CA+5PVA7yXH=U757w8V=Zj2U1URG4nYNav20NpjtQ4svVueyPNw@mail.gmail.com Reference: http://lkml.kernel.org/r/CA+55aFweWR=nDzc2Y=rCtL_H8JfdprQiCimN5dwc+TgyD4Bjsg@mail.gmail.com Signed-off-by: Jani Nikula --- drivers/gpu/drm/i915/intel_display.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) (limited to 'drivers') diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 1c12262029fb..30faf6c262e5 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -2439,7 +2439,11 @@ intel_find_plane_obj(struct intel_crtc *intel_crtc, return; if (intel_alloc_plane_obj(intel_crtc, plane_config)) { - update_state_fb(intel_crtc->base.primary); + struct drm_plane *primary = intel_crtc->base.primary; + + primary->state->crtc = &intel_crtc->base; + update_state_fb(primary); + return; } @@ -2464,11 +2468,14 @@ intel_find_plane_obj(struct intel_crtc *intel_crtc, continue; if (i915_gem_obj_ggtt_offset(obj) == plane_config->base) { + struct drm_plane *primary = intel_crtc->base.primary; + if (obj->tiling_mode != I915_TILING_NONE) dev_priv->preserve_bios_swizzle = true; drm_framebuffer_reference(c->primary->fb); - intel_crtc->base.primary->fb = c->primary->fb; + primary->fb = c->primary->fb; + primary->state->crtc = &intel_crtc->base; obj->frontbuffer_bits |= INTEL_FRONTBUFFER_PRIMARY(intel_crtc->pipe); break; } -- cgit v1.2.3 From 5f407751b0ca9bd876fe8f15ff28153661c6ba0a Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Wed, 25 Mar 2015 18:30:38 +0100 Subject: drm/i915: Fixup legacy plane->crtc link for initial fb config This is a very similar bug in the load detect code fixed in commit 9128b040eb774e04bc23777b005ace2b66ab2a85 Author: Daniel Vetter Date: Tue Mar 3 17:31:21 2015 +0100 drm/i915: Fix modeset state confusion in the load detect code But this time around it was the initial fb code that forgot to update the plane->crtc pointer. Otherwise it's the exact same bug, with the exact same restrains (any set_config call/ioctl that doesn't disable the pipe papers over the bug for free, so fairly hard to hit in normal testing). So if you want the full explanation just go read that one over there - it's rather long ... Cc: Matt Roper Cc: Linus Torvalds Cc: Chris Wilson Cc: Josh Boyer Cc: Jani Nikula Reported-and-tested-by: Josh Boyer Signed-off-by: Daniel Vetter [Jani: backported to drm-intel-fixes for v4.0-rc] Reference: http://mid.gmane.org/CA+5PVA7ChbtJrknqws1qvZcbrg1CW2pQAFkSMURWWgyASRyGXg@mail.gmail.com Signed-off-by: Jani Nikula --- drivers/gpu/drm/i915/intel_display.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers') diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 30faf6c262e5..f75173c20f47 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -2442,6 +2442,7 @@ intel_find_plane_obj(struct intel_crtc *intel_crtc, struct drm_plane *primary = intel_crtc->base.primary; primary->state->crtc = &intel_crtc->base; + primary->crtc = &intel_crtc->base; update_state_fb(primary); return; @@ -2476,6 +2477,7 @@ intel_find_plane_obj(struct intel_crtc *intel_crtc, drm_framebuffer_reference(c->primary->fb); primary->fb = c->primary->fb; primary->state->crtc = &intel_crtc->base; + primary->crtc = &intel_crtc->base; obj->frontbuffer_bits |= INTEL_FRONTBUFFER_PRIMARY(intel_crtc->pipe); break; } -- cgit v1.2.3