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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 16A7ACDB47E for ; Wed, 18 Oct 2023 14:04:09 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 79A6E10E090; Wed, 18 Oct 2023 14:04:08 +0000 (UTC) Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.120]) by gabe.freedesktop.org (Postfix) with ESMTPS id 96D7510E090; Wed, 18 Oct 2023 14:04:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1697637845; x=1729173845; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=f4Zq33cofTRUoDj4rxlYFHVD2+ecpwiue6b3v8VzX9o=; b=MctV8Ha63bLcqQ0d9O5BsIKk3HToL9vjzNrvdRQ30OiaAwzqRIjOikbf khmBueXDmr2CiX+q7cFLdEr8Ba/hN9UKzXGNPl9+tlSt4u6ipEvSXQ/UG tTtc6TYfB5BBLmtZKGeJ+QlYxOi/bWOM+dAK/Mhi7nRp5fxvpS1bygOH2 0EVlgdJChK/aJ8T3MrwKSrQamL2dZ6J48UBaOmHvF2UqirFjmzyZWkkvr WHAqUEKRhfQavhSDIRYZOwstL0JrXj5Gg3dxognwRLqi4cPGUKEu/eXrz jY8fndrPQa7GVJT6vBRLIFEL57eghFS+wav3ESQiKlKrPfTDjcUd++LmP w==; X-IronPort-AV: E=McAfee;i="6600,9927,10867"; a="384898156" X-IronPort-AV: E=Sophos;i="6.03,235,1694761200"; d="scan'208";a="384898156" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Oct 2023 07:04:04 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10867"; a="847278877" X-IronPort-AV: E=Sophos;i="6.03,235,1694761200"; d="scan'208";a="847278877" Received: from nirmoyda-mobl.ger.corp.intel.com (HELO [10.249.39.1]) ([10.249.39.1]) by fmsmga003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Oct 2023 07:04:02 -0700 Message-ID: <3887c6f2-687e-01d0-71c9-b2354a0df9c7@linux.intel.com> Date: Wed, 18 Oct 2023 16:04:00 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.15.1 Content-Language: en-US To: Andi Shyti References: <20231018093815.1349-1-nirmoy.das@intel.com> <36c0e644-4013-f2f8-a0a7-9b9c3d8423c9@linux.intel.com> From: Nirmoy Das In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Intel-gfx] [PATCH v3] drm/i915: Flush WC GGTT only on required platforms 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: , Cc: intel-gfx@lists.freedesktop.org, Jonathan Cavitt , stable@vger.kernel.org, dri-devel@lists.freedesktop.org, Rodrigo Vivi , Matt Roper , Nirmoy Das Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On 10/18/2023 3:00 PM, Andi Shyti wrote: > Hi Nirmoy, > >>>> gen8_ggtt_invalidate() is only needed for limited set of platforms >>>> where GGTT is mapped as WC. This was added as way to fix WC based GGTT in >>>> commit 0f9b91c754b7 ("drm/i915: flush system agent TLBs on SNB") and >>>> there are no reference in HW docs that forces us to use this on non-WC >>>> backed GGTT. >>>> >>>> This can also cause unwanted side-effects on XE_HP platforms where >>>> GFX_FLSH_CNTL_GEN6 is not valid anymore. >>>> >>>> v2: Add a func to detect wc ggtt detection (Ville) >>>> v3: Improve commit log and add reference commit (Daniel) >>>> >>>> Fixes: d2eae8e98d59 ("drm/i915/dg2: Drop force_probe requirement") >>> I'm wondering if this is the right Fixes, though. Should this >>> rather be: >>> >>> Fixes: 6266992cf105 ("drm/i915/gt: remove GRAPHICS_VER == 10") >> Hard to find a real Fixes for this. I just want to backport this to dg2 >> where we can have unwanted side-effects. > yes, this piece of code has moved around enough so to make it > diffuclt to track its origin. > > I think the one I found should be the correct one, That just removes a graphics ver, not related to WC GGTT map or XE_HP. > but the dg2 > force probe removeal can also become a placeholder for DG2 fixes. Yes, I have no better ideas too. Regards, Nirmoy > > I won't complain. > > Andi