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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 453CDC6FD1D for ; Wed, 15 Mar 2023 08:01:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231368AbjCOIBY (ORCPT ); Wed, 15 Mar 2023 04:01:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42538 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231531AbjCOIBW (ORCPT ); Wed, 15 Mar 2023 04:01:22 -0400 X-Greylist: delayed 543 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Wed, 15 Mar 2023 01:00:51 PDT Received: from new3-smtp.messagingengine.com (new3-smtp.messagingengine.com [66.111.4.229]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A49C7769D2 for ; Wed, 15 Mar 2023 01:00:51 -0700 (PDT) Received: from compute6.internal (compute6.nyi.internal [10.202.2.47]) by mailnew.nyi.internal (Postfix) with ESMTP id B77E8581D4B; Wed, 15 Mar 2023 03:51:17 -0400 (EDT) Received: from mailfrontend2 ([10.202.2.163]) by compute6.internal (MEProxy); Wed, 15 Mar 2023 03:51:17 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kroah.com; h=cc :cc:content-transfer-encoding:content-type:content-type:date :date:from:from:in-reply-to:in-reply-to:message-id:mime-version :references:reply-to:sender:subject:subject:to:to; s=fm2; t= 1678866677; x=1678873877; bh=aNNQwQzVCna7Ns3n6BIaF6xnV4h5OB3sXJx Eet6WtvI=; b=AoX0YRtx60/GyCP5Pl5C/3NEAIrDfj6bVizZsn+iolVqge4yWWq 3ly8MZ1OepeqQpI1D11wYodztO4Pk/bukfJuj72xH5loKvfG6GM9kR2QN6tnBVem UYv5uo4eABD+teMpY6x6ZRLw+V1aCZToFAbGndPQE9aDnwqJm3vAp8IXPfx0wrUP TrKsH2fLXCtzbURBMsf2+ffnv00YBDm2unZJ92Kq2Ov5p2ZOJWdocrOzyaQNipmf CSjH+i56xnuT3wV2CcjaDdJ0+TeF2bplcQTACgi2Uv+y7UpqQ2UE0YBI8lSynK5g GanOwJSFGIZahM9Jx1KxTkwnu9Rj785Qe7g== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-transfer-encoding :content-type:content-type:date:date:feedback-id:feedback-id :from:from:in-reply-to:in-reply-to:message-id:mime-version :references:reply-to:sender:subject:subject:to:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm2; t= 1678866677; x=1678873877; bh=aNNQwQzVCna7Ns3n6BIaF6xnV4h5OB3sXJx Eet6WtvI=; b=e4+sFXbrYfNrq6Md3CAaUb2PMMRL1BkxB/dBHXE8GvzTfOngDQZ MjQXj2w+xhNaypZh4CxSi2SOFxw0XsmcVXrBq/0PRihnGnsJ9MoPvoadfmYl3LVj KrvogBkdfg+o3cCE/lthP8+Xb4ryXUAOU7qq65cb3RUM9PN06ofNPPcZI6cNalXg syiYce7tdSduPq66/2uOwp1kJBxLGeeA9jU75XBh2BRv7sZuGz1jSKncvgq5cOej 7Caad7oS+1ZExNu9o6Do+4Mx/RcmBQNNWgJ3qkuF/DjLiH3hB1mMw43rns58NtPJ hbtQlV0omJtvEn7z3rr01cbSIgVA30LLDcg== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvhedrvddvjedguddutdcutefuodetggdotefrod ftvfcurfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfgh necuuegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmd enucfjughrpeffhffvvefukfhfgggtugfgjgesthekredttddtudenucfhrhhomhepifhr vghgucfmjfcuoehgrhgvgheskhhrohgrhhdrtghomheqnecuggftrfgrthhtvghrnhepge evleehjedtgfethfetveetheejtdeugeekgeevleetkeehvefghfdtueegteeknecuffho mhgrihhnpehfrhgvvgguvghskhhtohhprdhorhhgnecuvehluhhsthgvrhfuihiivgeptd enucfrrghrrghmpehmrghilhhfrhhomhepghhrvghgsehkrhhorghhrdgtohhm X-ME-Proxy: Feedback-ID: i787e41f1:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Wed, 15 Mar 2023 03:51:16 -0400 (EDT) Date: Wed, 15 Mar 2023 08:51:14 +0100 From: Greg KH To: John.C.Harrison@intel.com Cc: stable@vger.kernel.org, Chris Wilson , Joonas Lahtinen , Jani Nikula , Rodrigo Vivi , Tvrtko Ursulin , intel-gfx@lists.freedesktop.org, Jouni =?iso-8859-1?Q?H=F6gander?= , Daniele Ceraolo Spurio , Jani Nikula Subject: Re: [PATCH 5.4.y] drm/i915: Don't use BAR mappings for ring buffers with LLC Message-ID: References: <167820543971229@kroah.com> <20230314022211.1393031-1-John.C.Harrison@Intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20230314022211.1393031-1-John.C.Harrison@Intel.com> Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Mon, Mar 13, 2023 at 07:22:11PM -0700, John.C.Harrison@Intel.com wrote: > From: John Harrison > > Direction from hardware is that ring buffers should never be mapped > via the BAR on systems with LLC. There are too many caching pitfalls > due to the way BAR accesses are routed. So it is safest to just not > use it. > > Signed-off-by: John Harrison > Fixes: 9d80841ea4c9 ("drm/i915: Allow ringbuffers to be bound anywhere") > Cc: Chris Wilson > Cc: Joonas Lahtinen > Cc: Jani Nikula > Cc: Rodrigo Vivi > Cc: Tvrtko Ursulin > Cc: intel-gfx@lists.freedesktop.org > Cc: # v4.9+ > Tested-by: Jouni Högander > Reviewed-by: Daniele Ceraolo Spurio > Link: https://patchwork.freedesktop.org/patch/msgid/20230216011101.1909009-3-John.C.Harrison@Intel.com > (cherry picked from commit 65c08339db1ada87afd6cfe7db8e60bb4851d919) > Signed-off-by: Jani Nikula > (cherry picked from commit 85636167e3206c3fbd52254fc432991cc4e90194) > Signed-off-by: John Harrison > --- > drivers/gpu/drm/i915/gt/intel_ringbuffer.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) Also queued up for 5.10.y, you forgot that one :) thanks, greg k-h