On Mon, 13 Feb 2012 13:14:51 -0500
Sean Paul <seanpaul at chromium.org> wrote:
> 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);
> }
>
> }
Yeah, looks good.
Acked-by: Jesse Barnes <jbarnes at virtuousgeek.org>
--
Jesse Barnes, Intel Open Source Technology Center
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