drm/i915: assert panel is unlocked before writing transcoder timing regs

Otherwise our writes will be silently ignored.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 515e0b9..f274d5b 100644 (file)
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -2444,7 +2444,8 @@ static void ironlake_crtc_enable(struct drm_crtc *crtc)
                I915_WRITE(PCH_DPLL_SEL, temp);
        }
 
-       /* set transcoder timing */
+       /* set transcoder timing, panel must allow it */
+       assert_panel_unlocked(dev_priv, pipe);
        I915_WRITE(TRANS_HTOTAL(pipe), I915_READ(HTOTAL(pipe)));
        I915_WRITE(TRANS_HBLANK(pipe), I915_READ(HBLANK(pipe)));
        I915_WRITE(TRANS_HSYNC(pipe),  I915_READ(HSYNC(pipe)));