drm: i915: "plane B assertion failure, should be off on pipe B but is still active"

[Daniel Vetter]

On Sun, Jul 13, 2014 at 10:32:41PM +0200, Paul Bolle wrote:
> Paul Bolle schreef op wo 02-07-2014 om 10:53 [+0200]:
> > On Tue, 2014-07-01 at 12:17 +0300, Jani Nikula wrote:
> > > This does not ring any bells to me (but that doesn't prove anything). A
> > > bisect result would be awesome.
> 
> The bisect (which took me quite some time) points at commit 98ec77397a5c
> ("drm/i915: Make primary_enabled match the actual hardware state"). The
> bisect log is pasted at the end of this message.
> 
> Commit 98ec77397a5c reverts cleanly on top of v3.16-rc4. Booting
> v3.16-rc4 with that revert added makes the WARNING go away. But note
> that I have no idea whether that revert actually is a proper fix here.
> 
> Feel free to prod me for further testing, etc.

Please test the below patch, thanks.
-Daniel

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 82e7d57f0a8a..f0be855ddf45 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -11914,6 +11914,7 @@ static void intel_sanitize_crtc(struct intel_crtc *crtc)
 		 * ...  */
 		plane = crtc->plane;
 		crtc->plane = !plane;
+		crtc->primary_enabled = true;
 		dev_priv->display.crtc_disable(&crtc->base);
 		crtc->plane = plane;
 
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch