From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Widawsky Subject: Re: [PATCH] drm/i915: paper over missed irq issues with force wake vodoo Date: Tue, 10 Jan 2012 22:21:13 -0800 Message-ID: <4F0D2A59.9070906@bwidawsk.net> References: <1325702445-2231-1-git-send-email-daniel.vetter@ffwll.ch> <20120110122006.GD3979@phenom.ffwll.local> <87fwfnnjsz.fsf@eliezer.anholt.net> <861ur6alwb.fsf@sumi.keithp.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from cloud01.chad-versace.us (184-106-247-128.static.cloud-ips.com [184.106.247.128]) by gabe.freedesktop.org (Postfix) with ESMTP id 2AD779F76F for ; Tue, 10 Jan 2012 22:22:00 -0800 (PST) In-Reply-To: <861ur6alwb.fsf@sumi.keithp.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org Errors-To: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org To: Keith Packard Cc: Daniel Vetter , intel-gfx , Eugeni Dodonov , stable@kernel.org List-Id: intel-gfx@lists.freedesktop.org On 01/10/2012 08:44 PM, Keith Packard wrote: > On Tue, 10 Jan 2012 16:51:08 -0800, Eric Anholt wrote: > >> So they've gone out of their way to build broken stuff. Awesome. > > Well, in theory, the interrupt would be generated *before* the hardware > goes to RC6; when idle, I'm not exactly sure what the hardware would be > doing to generate interrupts. That's right. I think we need to think about the programming sequence a bit more. The GT should be smart enough to not sleep if it has any work pending that may generate interrupts. I don't think this by itself explans anything. > >> I'd say you've found the clue here -- I'm a lot happier with going with >> your patches now (and I was pretty happy with the gen7 side before). >> I'd just like to not mess with gen6 unless we've got missed irq bugs >> there to fix. > > Yeah, knowing that there might be interrupt funnies due to RC6 goes some > way to explaining why just avoiding RC6 helps. > > I wonder if any of this might explain the RC6 issues we see on SNB on > some hardware, and whether we should give this a try... I know, grasping > at straws, but still, it's about all we have at this point. > Just as a reminder, never going into rc6 never fixed any problems, so I still believe this is somehow timing related. ~Ben the pessimist