From 050b86b5bf2040a4be87f93510ffd780113c2065 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Wed, 29 Nov 2017 14:54:11 +0200 Subject: [PATCH] drm/i915: Fix deadlock in i830_disable_pipe() MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Chris Wilson Fixes: d87ce7640295 ("drm/i915: Add .get_hw_state() method for planes") Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20171129125411.29055-1-ville.syrjala@linux.intel.com (cherry picked from commit 5816d9cbc0a0fbf232fe297cefcb85361a3cde90) Signed-off-by: Jani Nikula Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/i915/intel_display.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 751b0f0..4648569 100644 --- 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_private *dev_priv, enum pipe pipe) 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)); -- 2.7.4