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 0AB4AFF885A for ; Tue, 28 Apr 2026 15:10:41 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 9CBC510E110; Tue, 28 Apr 2026 15:10:40 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="m70Vdp7/"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.9]) by gabe.freedesktop.org (Postfix) with ESMTPS id 877FE10EC2A for ; Tue, 28 Apr 2026 15:10:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1777389039; x=1808925039; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=e5Aia3lapZCgq06YmkguDvKlMUCzM00XkmsLRADP1b4=; b=m70Vdp7/pDSucpYieLv088nxykEU3pbvTshchaE631cK7VfxiIaIGzfM b0O3Ic3kGGiCqpGpWMdg+DVO4R1b4lnup/T6C+ybBV2vi+++KuKXHaId/ vIxQJ26MFDZXgf6e2EjFH371SqmsLPyuh7BDO3rZod/N2ZQuYWBFmVowJ 42W5sfSD+DxABQDcjn8Lh6PMQkzjhAZpqvk5B+avsmbGMKUjrE4v0gzCG 1PKBoHlGXQaa+P2Bncda7bOURMcST/ooWSpaScapjsj/BFNZl/H7WfCrn OO6JY3y82wZUQygdcwgf1qWD+YhSMPym/CI1W3pJRA/zjtV/PuJCkrB7z w==; X-CSE-ConnectionGUID: 1JCZuI6rRvWVVLgID7QZrQ== X-CSE-MsgGUID: nKXPHwHKSbar9Fe6hxqugw== X-IronPort-AV: E=McAfee;i="6800,10657,11770"; a="100956937" X-IronPort-AV: E=Sophos;i="6.23,204,1770624000"; d="scan'208";a="100956937" Received: from fmviesa004.fm.intel.com ([10.60.135.144]) by orvoesa101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Apr 2026 08:10:39 -0700 X-CSE-ConnectionGUID: 7PjhBtMuTKOXhlbiVK1IvA== X-CSE-MsgGUID: o6TJOrI2RcyL8j2rfIAfYA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.23,204,1770624000"; d="scan'208";a="235737806" Received: from ijarvine-mobl1.ger.corp.intel.com (HELO localhost) ([10.245.245.30]) by fmviesa004-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Apr 2026 08:10:37 -0700 Date: Tue, 28 Apr 2026 17:10:35 +0200 From: Andi Shyti To: Krzysztof Karas Cc: Sebastian Brzezinka , intel-gfx@lists.freedesktop.org, andi.shyti@linux.intel.com, stable@vger.kernel.org Subject: Re: [PATCH] drm/i915: skip __i915_request_skip() for already signaled requests Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" Hi Sebastian, On Mon, Apr 20, 2026 at 09:18:03AM +0000, Krzysztof Karas wrote: > On 2026-04-16 at 13:31:18 +0200, Sebastian Brzezinka wrote: > > After a GPU reset the HWSP is zeroed, so previously completed > > requests appear incomplete. If such a request is picked up during > > reset_rewind() and marked guilty, i915_request_set_error_once() > > returns early (fence already signaled), leaving fence.error without > > a fatal error code. The subsequent __i915_request_skip() then hits: > > ``` > > GEM_BUG_ON(!fatal_error(rq->fence.error)) > > ``` > > > > Fixes a kernel BUG observed on Sandy Bridge (Gen6) during > By "Fixes" do you mean this patch? Or are you referring to the > tag "Fixes:" below? If former would be the case, then imperative > form might be better: Fix. Pour parler: the imperative is used in the last paragraph: "Guard" :-) > > In any case the patch looks sane: > Reviewed-by: Krzysztof Karas > > > heartbeat-triggered engine resets. > > ``` > > kernel BUG at drivers/gpu/drm/i915/i915_request.c:556! > > RIP: __i915_request_skip+0x15e/0x1d0 [i915] > > ... > > __i915_request_reset+0x212/0xa70 [i915] > > reset_rewind+0xe4/0x280 [i915] > > intel_gt_reset+0x30d/0x5b0 [i915] > > heartbeat+0x516/0x530 [i915] > > ``` > > > > Guard __i915_request_skip() with i915_request_signaled(), if the > > fence is already signaled, the ring content is committed and there > > is nothing left to skip. > > > > Cc: stable@vger.kernel.org > > Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/work_items/13729 > > Fixes: 36e191f0644b ("drm/i915: Apply i915_request_skip() on submission") > > Signed-off-by: Sebastian Brzezinka Reviewed-by: Andi Shyti Thanks, Andi