From: Damien Lespiau Date: Thu, 5 Feb 2015 18:30:20 +0000 Subject: [PATCH] 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 --- drivers/gpu/drm/i915/intel_display.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index e116dee10cf9..177714a9d778 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, -- 2.1.0