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 5FB88C83F01 for ; Thu, 31 Aug 2023 14:01:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240931AbjHaOBM (ORCPT ); Thu, 31 Aug 2023 10:01:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52792 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229543AbjHaOBL (ORCPT ); Thu, 31 Aug 2023 10:01:11 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A4F68C3; Thu, 31 Aug 2023 07:01:06 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 5EA29B81EB8; Thu, 31 Aug 2023 14:01:05 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 93068C433C8; Thu, 31 Aug 2023 14:01:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1693490464; bh=bhdJzbcUDiU8F267YV9GPJNZorUfdGvRfv0Zanffxlc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=dt4grCozA/NuOXr8/L7WRrWozLJyn4aujUgLwxM1zCLIzhVDGU86YnC9Z1+oQ4yD4 eLcaMYJfwZ17CMnPDEYh7xhyCS6DgXJ3shvcan1nxj4IF9AkmJ9TOXwMnWLwFFZSAI /o84xxJ2DVEn56tt5q1w/mg3IWr9ZzKXEZ4WRrBI= Date: Thu, 31 Aug 2023 16:01:01 +0200 From: Greg KH To: Christian =?iso-8859-1?Q?K=F6nig?= Cc: Chia-I Wu , Sasha Levin , airlied@linux.ie, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, amd-gfx@lists.freedesktop.org, Alex Deucher , stable@vger.kernel.org, Lang Yu , Christian =?iso-8859-1?Q?K=F6nig?= Subject: Re: [PATCH AUTOSEL 5.10 13/22] drm/amdgpu: install stub fence into potential unused fence pointers Message-ID: <2023083144-railroad-daybreak-7f41@gregkh> References: <20230724012419.2317649-1-sashal@kernel.org> <20230724012419.2317649-13-sashal@kernel.org> <55fc4a28-1e17-44df-2069-a688828080e6@gmail.com> <2023083145-scoured-celery-2511@gregkh> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 31, 2023 at 03:26:28PM +0200, Christian König wrote: > Am 31.08.23 um 12:56 schrieb Greg KH: > > On Thu, Aug 31, 2023 at 12:27:27PM +0200, Christian König wrote: > > > Am 30.08.23 um 20:53 schrieb Chia-I Wu: > > > > On Sun, Jul 23, 2023 at 6:24 PM Sasha Levin wrote: > > > > > From: Lang Yu > > > > > > > > > > [ Upstream commit 187916e6ed9d0c3b3abc27429f7a5f8c936bd1f0 ] > > > > > > > > > > When using cpu to update page tables, vm update fences are unused. > > > > > Install stub fence into these fence pointers instead of NULL > > > > > to avoid NULL dereference when calling dma_fence_wait() on them. > > > > > > > > > > Suggested-by: Christian König > > > > > Signed-off-by: Lang Yu > > > > > Reviewed-by: Christian König > > > > > Signed-off-by: Alex Deucher > > > > > Signed-off-by: Sasha Levin > > > > > --- > > > > > drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 6 ++++-- > > > > > 1 file changed, 4 insertions(+), 2 deletions(-) > > > > We start getting this warning spew on chromeos > > > Yeah because the older kernels still kept track of the last VM fence in the > > > syncobj. > > > > > > This patch here should probably not have been back ported. > > > > > > Why was that done anyway? The upstream commit doesn't have a CC stable and > > > this is only a bug fix for a new feature not present on older kernels. > > It is part of the AUTOSEL process. > > Could we prevent patches from being backported by adding a Fixes: tag? Yes, that will show exactly where the patch should be backported to. thanks, greg k-h