From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga18.intel.com (mga18.intel.com [134.134.136.126]) by gabe.freedesktop.org (Postfix) with ESMTPS id 4589089F27 for ; Sun, 12 Jan 2020 02:57:24 +0000 (UTC) Date: Sat, 11 Jan 2020 18:57:22 -0800 Message-ID: <875zhhtm99.wl-ashutosh.dixit@intel.com> From: "Dixit, Ashutosh" In-Reply-To: <157873229910.10140.6691170131873194678@skylake-alporthouse-com> References: <037121df1ee6fcf1fa92ea4a7fb6ba31b39e80ac.1578720512.git.ashutosh.dixit@intel.com> <157873229910.10140.6691170131873194678@skylake-alporthouse-com> MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Subject: Re: [igt-dev] [PATCH i-g-t 2/2] i915/treewide: Replace gem_mmap__gtt() by gem_mmap__device_coherent() List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: igt-dev-bounces@lists.freedesktop.org Sender: "igt-dev" To: Chris Wilson Cc: igt-dev@lists.freedesktop.org List-ID: On Sat, 11 Jan 2020 00:44:59 -0800, Chris Wilson wrote: > > Here, we want OFFSET_WC etc added. So leave this style for a later patch, > and focus on just converting the ones where we want any old mapping to > device_coherent(). Another patch can focus on converting any __cpu maps > that are only used for writes to device_coherent. Thanks for the feedback Chris, makes sense, will rework and repost. Some time ago, Dixit, Ashutosh wrote: > On Sat, 11 Jan 2020 00:40:32 -0800, Chris Wilson wrote: > > Quoting Ashutosh Dixit (2020-01-11 05:36:52) > > > In order to preserve legacy behavior for devices with a mappable > > > aperture try a GTT mapping first. Use a WC mapping only for devices > > > without a mappable aperture. > > > > No...? It's just historical legacy from before we even had WC available. > > Since we've had WC for basic mmappings, we prefer WC since it is not as > > scarce and as precious a resource. (Not that it matters for most tests > > since GTT thrashing in basic igt is unheard of!) About this, I was assuming if we were using WC instead of GTT on legacy (Gen < 6), we would have to set read/write domains to WC too, unless you are saying it's not required? (From what I know, for later Gen's, setting the domain to either GTT or WC is identical). _______________________________________________ igt-dev mailing list igt-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/igt-dev