Prevent a divide-by-zero by consistently treating an 'active' CRTC without a mode set as actually disabled. This looks to have been first introduced with commit 24929352481f085c5f85d4d4cbc919ddf106d381 Author: Daniel Vetter <daniel.vetter at ffwll.ch> Date: Mon Jul 2 20:28:59 2012 +0200 drm/i915: read out the modeset hw state at load and resume time but then combined with commit b0a2658acb5bf9ca86b4aab011b7106de3af0add Author: Daniel Vetter <daniel.vetter at ffwll.ch> Date: Tue Dec 18 09:37:54 2012 +0100 drm/i915: don't disable disconnected outputs it finally started oopsing. Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk> Reported-and-tested-by: Alexey Zaytsev <alexey.zaytsev at gmail.com> Tested-by: Sedat Dilek <sedat.dilek at gmail.com> Cc: Daniel Vetter <daniel.vetter at ffwll.ch> Cc: Jesse Barnes <jbarnes at virtuousgeek.org> Cc: stable at vger.kernel.org --- drivers/gpu/drm/i915/intel_pm.c | 25 ++++++++++++++++--------- 1 file changed, 16 insertions(+), 9 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c index e6f54ff..e83a117 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -44,6 +44,14 @@ * i915.i915_enable_fbc parameter */ +static bool intel_crtc_active(struct drm_crtc *crtc) +{ + /* Be paranoid as we can arrive here with only partial + * state retrieved from the hardware during setup. + */ + return to_intel_crtc(crtc)->active && crtc->fb && crtc->mode.clock; +} + static void i8xx_disable_fbc(struct drm_device *dev) { struct drm_i915_private *dev_priv = dev->dev_private; @@ -405,9 +413,8 @@ void intel_update_fbc(struct drm_device *dev) * - going to an unsupported config (interlace, pixel multiply, etc.) */ list_for_each_entry(tmp_crtc, &dev->mode_config.crtc_list, head) { - if (to_intel_crtc(tmp_crtc)->active && - !to_intel_crtc(tmp_crtc)->primary_disabled && - tmp_crtc->fb) { + if (intel_crtc_active(tmp_crtc) && + !to_intel_crtc(tmp_crtc)->primary_disabled) { if (crtc) { DRM_DEBUG_KMS("more than one pipe active, disabling compression\n"); dev_priv->no_fbc_reason = FBC_MULTIPLE_PIPES; @@ -992,7 +999,7 @@ static struct drm_crtc *single_enabled_crtc(struct drm_device *dev) struct drm_crtc *crtc, *enabled = NULL; list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) { - if (to_intel_crtc(crtc)->active && crtc->fb) { + if (intel_crtc_active(crtc)) { if (enabled) return NULL; enabled = crtc; @@ -1086,7 +1093,7 @@ static bool g4x_compute_wm0(struct drm_device *dev, int entries, tlb_miss; crtc = intel_get_crtc_for_plane(dev, plane); - if (crtc->fb == NULL || !to_intel_crtc(crtc)->active) { + if (!intel_crtc_active(crtc)) { *cursor_wm = cursor->guard_size; *plane_wm = display->guard_size; return false; @@ -1215,7 +1222,7 @@ static bool vlv_compute_drain_latency(struct drm_device *dev, int entries; crtc = intel_get_crtc_for_plane(dev, plane); - if (crtc->fb == NULL || !to_intel_crtc(crtc)->active) + if (!intel_crtc_active(crtc)) return false; clock = crtc->mode.clock; /* VESA DOT Clock */ @@ -1476,7 +1483,7 @@ static void i9xx_update_wm(struct drm_device *dev) fifo_size = dev_priv->display.get_fifo_size(dev, 0); crtc = intel_get_crtc_for_plane(dev, 0); - if (to_intel_crtc(crtc)->active && crtc->fb) { + if (intel_crtc_active(crtc)) { int cpp = crtc->fb->bits_per_pixel / 8; if (IS_GEN2(dev)) cpp = 4; @@ -1490,7 +1497,7 @@ static void i9xx_update_wm(struct drm_device *dev) fifo_size = dev_priv->display.get_fifo_size(dev, 1); crtc = intel_get_crtc_for_plane(dev, 1); - if (to_intel_crtc(crtc)->active && crtc->fb) { + if (intel_crtc_active(crtc)) { int cpp = crtc->fb->bits_per_pixel / 8; if (IS_GEN2(dev)) cpp = 4; @@ -2044,7 +2051,7 @@ sandybridge_compute_sprite_wm(struct drm_device *dev, int plane, int entries, tlb_miss; crtc = intel_get_crtc_for_plane(dev, plane); - if (crtc->fb == NULL || !to_intel_crtc(crtc)->active) { + if (!intel_crtc_active(crtc)) { *sprite_wm = display->guard_size; return false; } -- 1.7.10.4