Re: [PATCH] DRM/i915: Remove magic to prevent blank screen on gen4 chipsets

[Daniel Vetter <daniel@ffwll.ch>]

On Mon, Jul 07, 2014 at 06:20:34PM +0200, Egbert Eich wrote:
> Since the root cause is understood now and with the fix
> 
>    commit 564ed191f5d816d24501664296991ec70327e2bc
>    Author: Imre Deak <imre.deak@intel.com>
>    Date:   Fri Jun 13 14:54:21 2014 +0300
> 
>        drm/i915: gmch: fix stuck primary plane due to memory self-refresh mode
> 
> in place the magic for G4x chipsets introduced with commit
> 
>    commit 61bc95c1fbbb6a08b55bbe161fdf1ea5493fc595
>    Author: Egbert Eich <eich@suse.com>
>    Date:   Mon Mar 4 09:24:38 2013 -0500
> 
>        DRM/i915: On G45 enable cursor plane briefly after enabling the display plane.
> 
> to avoided occasional screen blanking on mode changes can finally
> be removed.
> It's been verified that Imre's fix also resolves the said issue.
> 
> Signed-off-by: Egbert Eich <eich@suse.de>
> Tested-by: Stefan Dirsch <sndirsch@suse.de>

Queued for -next, thanks for the patch.
-Daniel

> ---
>  drivers/gpu/drm/i915/intel_display.c | 27 ---------------------------
>  1 file changed, 27 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index b9bc030..8c3dcdf 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -3894,30 +3894,6 @@ static void intel_crtc_dpms_overlay(struct intel_crtc *intel_crtc, bool enable)
>  	 */
>  }
>  
> -/**
> - * i9xx_fixup_plane - ugly workaround for G45 to fire up the hardware
> - * cursor plane briefly if not already running after enabling the display
> - * plane.
> - * This workaround avoids occasional blank screens when self refresh is
> - * enabled.
> - */
> -static void
> -g4x_fixup_plane(struct drm_i915_private *dev_priv, enum pipe pipe)
> -{
> -	u32 cntl = I915_READ(CURCNTR(pipe));
> -
> -	if ((cntl & CURSOR_MODE) == 0) {
> -		u32 fw_bcl_self = I915_READ(FW_BLC_SELF);
> -
> -		I915_WRITE(FW_BLC_SELF, fw_bcl_self & ~FW_BLC_SELF_EN);
> -		I915_WRITE(CURCNTR(pipe), CURSOR_MODE_64_ARGB_AX);
> -		intel_wait_for_vblank(dev_priv->dev, pipe);
> -		I915_WRITE(CURCNTR(pipe), cntl);
> -		I915_WRITE(CURBASE(pipe), I915_READ(CURBASE(pipe)));
> -		I915_WRITE(FW_BLC_SELF, fw_bcl_self);
> -	}
> -}
> -
>  static void intel_crtc_enable_planes(struct drm_crtc *crtc)
>  {
>  	struct drm_device *dev = crtc->dev;
> @@ -3930,9 +3906,6 @@ static void intel_crtc_enable_planes(struct drm_crtc *crtc)
>  
>  	intel_enable_primary_hw_plane(dev_priv, plane, pipe);
>  	intel_enable_planes(crtc);
> -	/* The fixup needs to happen before cursor is enabled */
> -	if (IS_G4X(dev))
> -		g4x_fixup_plane(dev_priv, pipe);
>  	intel_crtc_update_cursor(crtc, true);
>  	intel_crtc_dpms_overlay(intel_crtc, true);
>  
> -- 
> 1.8.4.5
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch