This patch replaces the locking from the downclock routines with an assert
to ensure the registers are indeed unlocked. Without this patch, pre-SNB
devices would lock the registers when downclocking which would cause a
WARNING on suspend/resume with downclocking enabled.
Note: To hit this bug, you need to have lvds downclocking enabled.
Signed-off-by: Sean Paul <seanpaul at chromium.org>
---
drivers/gpu/drm/i915/intel_display.c | 14 ++------------
1 files changed, 2 insertions(+), 12 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index ebe71ed..33ef4f3 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -6968,9 +6968,7 @@ static void intel_increase_pllclock(struct drm_crtc *crtc)
if (!HAS_PIPE_CXSR(dev) && (dpll & DISPLAY_RATE_SELECT_FPA1)) {
DRM_DEBUG_DRIVER("upclocking LVDS\n");
- /* Unlock panel regs */
- I915_WRITE(PP_CONTROL,
- I915_READ(PP_CONTROL) | PANEL_UNLOCK_REGS);
+ assert_panel_unlocked(dev_priv, pipe);
dpll &= ~DISPLAY_RATE_SELECT_FPA1;
I915_WRITE(dpll_reg, dpll);
@@ -6979,9 +6977,6 @@ static void intel_increase_pllclock(struct drm_crtc *crtc)
dpll = I915_READ(dpll_reg);
if (dpll & DISPLAY_RATE_SELECT_FPA1)
DRM_DEBUG_DRIVER("failed to upclock LVDS!\n");
-
- /* ...and lock them again */
- I915_WRITE(PP_CONTROL, I915_READ(PP_CONTROL) & 0x3);
}
/* Schedule downclock */
@@ -7011,9 +7006,7 @@ static void intel_decrease_pllclock(struct drm_crtc *crtc)
if (!HAS_PIPE_CXSR(dev) && intel_crtc->lowfreq_avail) {
DRM_DEBUG_DRIVER("downclocking LVDS\n");
- /* Unlock panel regs */
- I915_WRITE(PP_CONTROL, I915_READ(PP_CONTROL) |
- PANEL_UNLOCK_REGS);
+ assert_panel_unlocked(dev_priv, pipe);
dpll |= DISPLAY_RATE_SELECT_FPA1;
I915_WRITE(dpll_reg, dpll);
@@ -7021,9 +7014,6 @@ static void intel_decrease_pllclock(struct drm_crtc *crtc)
dpll = I915_READ(dpll_reg);
if (!(dpll & DISPLAY_RATE_SELECT_FPA1))
DRM_DEBUG_DRIVER("failed to downclock LVDS!\n");
-
- /* ...and lock them again */
- I915_WRITE(PP_CONTROL, I915_READ(PP_CONTROL) & 0x3);
}
}
--
1.7.7.3
