Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752330Ab1FORML (ORCPT ); Wed, 15 Jun 2011 13:12:11 -0400 Received: from hapkido.dreamhost.com ([66.33.216.122]:43922 "EHLO hapkido.dreamhost.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751310Ab1FORMH (ORCPT ); Wed, 15 Jun 2011 13:12:07 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=whitecape.org; h=message-id:date :from:mime-version:to:cc:subject:references:in-reply-to :content-type:content-transfer-encoding; q=dns; s=whitecape.org; b=EtDGRPoRb1ooa5bPLuL2jJGPE7/NqfJAD9pNOJp0qvjGcFZZvdAtTAG0g7wpF NxJ98KcxneT99XlJURsZwvN0UoiDOfXyuQzUmNgCECAyg3W7CZA2mTwiPBtr/pxl 2Cw6Qo9dbgLV0eSuJKYhxmbRQJO4lNbMN9ea72tj/VT8Zo= Message-ID: <4DF8E7D1.7030104@whitecape.org> Date: Wed, 15 Jun 2011 10:11:45 -0700 From: Kenneth Graunke User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.17) Gecko/20110503 Thunderbird/3.1.10 MIME-Version: 1.0 To: Daniel J Blueman Cc: Eric Anholt , intel-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org, Dave Airlie Subject: Re: [Intel-gfx] [PATCH 3.0-rc3] i915: Fix gen6 (SNB) GPU stalling References: <1308070307-2630-1-git-send-email-daniel.blueman@gmail.com> In-Reply-To: <1308070307-2630-1-git-send-email-daniel.blueman@gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2688 Lines: 66 On 06/14/2011 09:51 AM, Daniel J Blueman wrote: > On 14 June 2011 13:23, Eric Anholt wrote: >> On Tue, 14 Jun 2011 12:18:36 +0800, Daniel J Blueman wrote: >>> Hi Eric, >>> >>> The frequent ~1.5s pauses I hit with SNB hardware in the gnome3 UI (eg >>> whenever you hit the top-left of the screen to show all windows) are >>> nicely addressed by your recent wake patch [1] (ported to -rc3). Thus >>> I see no 'missed IRQ' kernel messages. >>> >>> As this addresses a significant usability regression, are you happy to >>> add it to the 3.0-rc queue? I think it has very good value in -stable >>> also (assuming correctness). What do you think? >> >> This one had significant performance impacts, and later hacks in this >> series worked around the problem to approximately the same level of >> success with less impact, and we don't actually have a justification of >> why any of them work. We were still hoping to come up with some clue, >> and haven't yet. > > True; that is quite heavy handed delay looping. > > It's a pity the usual Intel font didn't make it to the programmer's > reference manuals. Anyway, unmasking the blitter user interrupt in the hardware > status mask register addresses the root cause. Out of reset it's FFFFFFFFh, > so we don't need to read it here. > > It would be good to get this into -rc4. -stable probably needs some additional > tweaks. > > Signed-off-by: Daniel J Blueman > --- > drivers/gpu/drm/i915/i915_irq.c | 6 ++++++ > 1 files changed, 6 insertions(+), 0 deletions(-) > > diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c > index b9fafe3..9a98c1b 100644 > --- a/drivers/gpu/drm/i915/i915_irq.c > +++ b/drivers/gpu/drm/i915/i915_irq.c > @@ -1827,6 +1827,12 @@ int ironlake_irq_postinstall(struct drm_device *dev) > ironlake_enable_display_irq(dev_priv, DE_PCU_EVENT); > } > > + if (IS_GEN6(dev)) > + /* allow blitter user interrupt to generate a MSI write from > + the ISR */ > + I915_WRITE(GEN6_BLITTER_HWSTAM, > + 0xffffffff& ~GEN6_BLITTER_USER_INTERRUPT); > + > return 0; > } > Tested-by: Kenneth Graunke With i915.semaphores=0 on my Lenovo T420s, I reliably saw missed IRQs from the blitter when using GNOME Shell or running GLBenchmark 2.0/Egypt. Applying this patch fixes the issue, making my system much more responsive. Thanks, Daniel! -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/