From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.9]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E87F628F935 for ; Tue, 28 Apr 2026 15:10:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.9 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777389041; cv=none; b=oIg33akWvUy+STimAO4nPonB1ZhBeWyfrmPuLGTRkdCdBdkFB3uSJh7tn4OS6QNJZltUNEYV8H55wq+tZR4IV+m4cAzQLumZlKpNSEDT3Xiw2CgvxudwU9OKWl/TlETCqpCEHnF3+/2XavP7EHgcMjgk9W+cdD/fnCpGXRJ7qbw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777389041; c=relaxed/simple; bh=e5Aia3lapZCgq06YmkguDvKlMUCzM00XkmsLRADP1b4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Jrjhv+fjAuSDHNNSfGLKpm1cqoj200tWRQN6L19cuEyqJjgMpzai62ZQ83wFz+FrjDibCesX0tY0GLqWlTNAagabtDclADizIhbCsCyM6dF0l7EDJdnOzuqL5MDY2J9OKou6cmANp+3KfPdTFD8YKAYAf2HymAEtzn8o/KHjIIQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=pass smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=Ig/ckKhq; arc=none smtp.client-ip=198.175.65.9 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="Ig/ckKhq" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1777389040; x=1808925040; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=e5Aia3lapZCgq06YmkguDvKlMUCzM00XkmsLRADP1b4=; b=Ig/ckKhq5V3Mn0P2c5UIyPuNcyhRgr58IJFyPWEaGiGEB8nFEyUWHuss TvvXDEUYlhAZX8vabzIYE4vCEn+0pxCXIxMv/j3Unz3E3irQKXk08dpGK KseUKyC641wnW5LFoHRAt5MJzzVUiLjkZf3XVxH/zbcm4ZDvjrmzma70+ YLBB3x3/Mh1B2fV1AL0QWqg00+7xvc6s3DgQ1AMcseto8w5aTsYTGQ+yb Ll3Kf7lCegAE77KAzDsF8wJ8aawGLmqJi2fA14DITvdCg6hev+ZXVTK+q T8ApjoTzaEWufB9yGrLAPBgELjWRkjHTVuft5T9cN+jjqCedWnK5dH5TH Q==; X-CSE-ConnectionGUID: TsxMvhiHSvGU5RKD/xd/QQ== X-CSE-MsgGUID: 7MVYYsNoR7O85jfN/GY7eA== X-IronPort-AV: E=McAfee;i="6800,10657,11770"; a="100956938" X-IronPort-AV: E=Sophos;i="6.23,204,1770624000"; d="scan'208";a="100956938" 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: Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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