From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 91616C433E5 for ; Fri, 24 Jul 2020 08:29:23 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 3C75F206EB for ; Fri, 24 Jul 2020 08:29:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3C75F206EB Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=chris-wilson.co.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id D5E376E4DD; Fri, 24 Jul 2020 08:29:22 +0000 (UTC) Received: from fireflyinternet.com (unknown [77.68.26.236]) by gabe.freedesktop.org (Postfix) with ESMTPS id 918BC6E946 for ; Fri, 24 Jul 2020 08:29:21 +0000 (UTC) X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.65.138; Received: from localhost (unverified [78.156.65.138]) by fireflyinternet.com (Firefly Internet (M1)) with ESMTP (TLS) id 21915383-1500050 for multiple; Fri, 24 Jul 2020 09:29:18 +0100 MIME-Version: 1.0 In-Reply-To: <87wo2t1hwv.fsf@gaia.fi.intel.com> References: <20200723174144.22195-2-chris@chris-wilson.co.uk> <20200723181001.22711-1-chris@chris-wilson.co.uk> <87wo2t1hwv.fsf@gaia.fi.intel.com> From: Chris Wilson To: Mika Kuoppala , intel-gfx@lists.freedesktop.org Date: Fri, 24 Jul 2020 09:29:17 +0100 Message-ID: <159557935746.21069.16433346717591004164@build.alporthouse.com> User-Agent: alot/0.9 Subject: Re: [Intel-gfx] [PATCH] drm/i915/gt: Stall around xcs invalidations on tgl X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" Quoting Mika Kuoppala (2020-07-24 08:38:56) > Chris Wilson writes: > > > Whether this is an arbitrary stall or a vital ingredient, neverthess the > > impact is noticeable. If we do not have the stall around the xcs > > invalidation before a request, writes within that request sometimes go > > astray. > > > > Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/2169 > > Signed-off-by: Chris Wilson > > Cc: Mika Kuoppala > > --- > > drivers/gpu/drm/i915/gt/intel_lrc.c | 18 ++++++++++++------ > > 1 file changed, 12 insertions(+), 6 deletions(-) > > > > diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c > > index 353b1717fe84..7d914527d236 100644 > > --- a/drivers/gpu/drm/i915/gt/intel_lrc.c > > +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c > > @@ -4761,10 +4761,12 @@ static int gen12_emit_flush_render(struct i915_request *request, > > > > static int gen12_emit_flush(struct i915_request *request, u32 mode) > > { > > +#define WA_CNT 16 /* Magic delay or size of some internal pipelined buffer? */ > > Odd, very odd indeed. > > I looked at the selftest in question. For completeness, there should be > READ_ONCE on where the hwsp is read, but that is just a makeup. > > But how about forcing the write completion check on, on the actual > write to the hwsp? It is enabled with bit 10. Nope. Which is a relief, since I'd working on the assumption that the delay needs to be before the write not after. -Chris _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx