From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Wilson Subject: Re: [PATCH] drm/i915: Quirk the pipe A quirk in the modeset state checker Date: Wed, 29 May 2013 10:06:20 +0100 Message-ID: <20130529090620.GC16225@cantiga.alporthouse.com> References: <1369812502-12999-1-git-send-email-daniel.vetter@ffwll.ch> <1369816889-22871-1-git-send-email-daniel.vetter@ffwll.ch> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1369816889-22871-1-git-send-email-daniel.vetter@ffwll.ch> Sender: stable-owner@vger.kernel.org To: Daniel Vetter Cc: Intel Graphics Development , stable@vger.kernel.org List-Id: intel-gfx@lists.freedesktop.org On Wed, May 29, 2013 at 10:41:29AM +0200, Daniel Vetter wrote: > If we always force the pipe A to on we can't use the hw state to > decide whether it should be on. Hence quirk the quirk. > > The problem is that crtc->active tracks the state of the entire > display pipe, i.e. including planes, encoders and all. But our hw > state readout simply looks at the pipe. But with the pipe A quirk we > force-enable that (together with it's pll). To fix that mismatch we > have two options: > - Quirk the checked state to match what our sw tracking states if the > pipe A quirk is in effect. > - Improve the hw state readout to not get fooled by the pipe A quirk. > > Since we already have similar state clamping in e.g. assert_pipe I've > opted for the first variant. Also note that we don't really loose any > state checking: Individual pieces of the abstract crtc pipe are > checked in the enable/disable functions with the various asssert_* > checks we have, and the hw state check code doesn't check anything if > the pipe is off anyway. > > v2: Pimp commit message after discussion with Chris and only apply the > quirk for the quirk if we're checking pipe A. Otherwise we'll miss > state checking for pipe B on i830M ... > > v3: Make the code comment consistent with the improved commit message, > too (Chris). > > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=64764 > Cc: stable@vger.kernel.org > Cc: Chris Wilson > Reported-and-Tested-by: mlsemon35@gmail.com (v1) > Signed-off-by: Daniel Vetter Reviewed-by: Chris Wilson -Chris -- Chris Wilson, Intel Open Source Technology Centre