This is a note to let you know that I've just added the patch titled
drm/i915: Fix deadlock in i830_disable_pipe()
to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: drm-i915-fix-deadlock-in-i830_disable_pipe.patch and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From 4488496d58200c7511842e049a4cc891d928da56 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= ville.syrjala@linux.intel.com Date: Wed, 29 Nov 2017 14:54:11 +0200 Subject: drm/i915: Fix deadlock in i830_disable_pipe() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit
From: Ville Syrjälä ville.syrjala@linux.intel.com
commit 4488496d58200c7511842e049a4cc891d928da56 upstream.
i830_disable_pipe() gets called from the power well code, and thus we're already holding the power domain mutex. That means we can't call plane->get_hw_state() as it will also try to grab the same mutex and will thus deadlock.
Replace the assert_plane() calls (which calls ->get_hw_state()) with just raw register reads in i830_disable_pipe(). As a bonus we can now get a warning if plane C is enabled even though we don't even expose it as a drm plane.
v2: Do a separate WARN_ON() for each plane (Chris)
Cc: Chris Wilson chris@chris-wilson.co.uk Reviewed-by: Chris Wilson chris@chris-wilson.co.uk Fixes: d87ce7640295 ("drm/i915: Add .get_hw_state() method for planes") Signed-off-by: Ville Syrjälä ville.syrjala@linux.intel.com Link: https://patchwork.freedesktop.org/patch/msgid/20171129125411.29055-1-ville.s... (cherry picked from commit 5816d9cbc0a0fbf232fe297cefcb85361a3cde90) Signed-off-by: Jani Nikula jani.nikula@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/gpu/drm/i915/intel_display.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
--- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -14717,8 +14717,11 @@ void i830_disable_pipe(struct drm_i915_p DRM_DEBUG_KMS("disabling pipe %c due to force quirk\n", pipe_name(pipe));
- assert_planes_disabled(intel_get_crtc_for_pipe(dev_priv, PIPE_A)); - assert_planes_disabled(intel_get_crtc_for_pipe(dev_priv, PIPE_B)); + WARN_ON(I915_READ(DSPCNTR(PLANE_A)) & DISPLAY_PLANE_ENABLE); + WARN_ON(I915_READ(DSPCNTR(PLANE_B)) & DISPLAY_PLANE_ENABLE); + WARN_ON(I915_READ(DSPCNTR(PLANE_C)) & DISPLAY_PLANE_ENABLE); + WARN_ON(I915_READ(CURCNTR(PIPE_A)) & CURSOR_MODE); + WARN_ON(I915_READ(CURCNTR(PIPE_B)) & CURSOR_MODE);
I915_WRITE(PIPECONF(pipe), 0); POSTING_READ(PIPECONF(pipe));
Patches currently in stable-queue which might be from ville.syrjala@linux.intel.com are
queue-4.14/drm-i915-redo-plane-sanitation-during-readout.patch queue-4.14/drm-i915-add-.get_hw_state-method-for-planes.patch queue-4.14/drm-i915-fix-deadlock-in-i830_disable_pipe.patch