From 12d17f9057f1255601a566be5c0665615657921e Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Fri, 2 Aug 2013 20:37:39 +0100 Subject: [PATCH] drm/i915: Do not dereference NULL crtc or fb until after checking Fixes regression from commit 4906557eb37b7fef84fad4304acef6dedf919880 Author: Rodrigo Vivi Date: Thu Jul 11 18:45:05 2013 -0300 drm/i915: Hook PSR functionality Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=67526 Signed-off-by: Chris Wilson Cc: Rodrigo Vivi Cc: Ben Widawsky Cc: Daniel Vetter --- drivers/gpu/drm/i915/intel_dp.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index 928b42f..7e16c6e 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -1514,10 +1514,10 @@ static bool intel_edp_psr_match_conditions(struct intel_dp *intel_dp) struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp); struct drm_device *dev = dig_port->base.base.dev; struct drm_i915_private *dev_priv = dev->dev_private; - struct drm_crtc *crtc = dig_port->base.base.crtc; - struct intel_crtc *intel_crtc = to_intel_crtc(crtc); - struct drm_i915_gem_object *obj = to_intel_framebuffer(crtc->fb)->obj; - struct intel_encoder *intel_encoder = &dp_to_dig_port(intel_dp)->base; + struct drm_crtc *crtc; + struct intel_crtc *intel_crtc; + struct drm_i915_gem_object *obj; + struct intel_encoder *intel_encoder; if (!IS_HASWELL(dev)) { DRM_DEBUG_KMS("PSR not supported on this platform\n"); @@ -1544,12 +1544,21 @@ static bool intel_edp_psr_match_conditions(struct intel_dp *intel_dp) return false; } + crtc = dig_port->base.base.crtc; + if (crtc == NULL) { + DRM_DEBUG_KMS("crtc not active for PSR\n"); + dev_priv->no_psr_reason = PSR_CRTC_NOT_ACTIVE; + return false; + } + + intel_crtc = to_intel_crtc(crtc); if (!intel_crtc->active || !crtc->fb || !crtc->mode.clock) { DRM_DEBUG_KMS("crtc not active for PSR\n"); dev_priv->no_psr_reason = PSR_CRTC_NOT_ACTIVE; return false; } + obj = to_intel_framebuffer(crtc->fb)->obj; if (obj->tiling_mode != I915_TILING_X || obj->fence_reg == I915_FENCE_REG_NONE) { DRM_DEBUG_KMS("PSR condition failed: fb not tiled or fenced\n"); -- 1.8.4.rc0