From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 E9B5E223DC6; Sat, 30 May 2026 18:13:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780164801; cv=none; b=hpx8mwzUCkT1IJaWIc1J1CC/48TFxJFGlwJLrfiElJTA9rIy348O7H7QoeG7SSAiyUuJfchSO6m3XabUmIJnAl/WW6Fhdg46j6Y/UymP6FxtPC90N1op2Utn7CAPRck9HNKTbkUaM7O2w3pSrullNfl2dAb1Ildg/vH3ZtC0nmM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780164801; c=relaxed/simple; bh=cbjcytuIskpXVFOUz3TE97PhIWAAdmb1Jgr33SadYE0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=IXQhXjZAMhd97Z2PFFa/9KplB6UqZiZNsCzuW9J4MIqSIXVAr/v9d+9Ty7IB7eXYuUgLaP8vVRugY0ZY8VpPBshWvy23XdI1dMSjEUGUnJsPmEun2363YyLeINjbCYJ48gcaAyk8I3cUZnBDaJpZHjFvYRg1zUVbfbps5EE2/aE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ynshIHbf; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="ynshIHbf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3AF1E1F00893; Sat, 30 May 2026 18:13:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1780164800; bh=E4xEX2FV4+M8rnk7dwu3WKIntHNL3HnmOTA/r6pC7Xg=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=ynshIHbf/ygXotVC6SgbiqShlqMgugpLDX/0NgYzDADdmxgn72osCEG01+j8sJ5a7 7B5hdNJCq4pgXyzMIC1TPljo/DUujbP1Ya9oa9Jld5dEDbbRay0yVAUETEMeaAKjkw ztE8D3kUSDNmrtSTMo7pLYi8p+VzgQpppCHDGKMY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Sebastian Brzezinka , Krzysztof Karas , Andi Shyti , Tvrtko Ursulin Subject: [PATCH 5.15 664/776] drm/i915: skip __i915_request_skip() for already signaled requests Date: Sat, 30 May 2026 18:06:18 +0200 Message-ID: <20260530160257.052007704@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260530160240.228940103@linuxfoundation.org> References: <20260530160240.228940103@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sebastian Brzezinka commit 4cfe4c0efbdcde742a47813180cc69b132d7598e upstream. 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 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. Fixes: 36e191f0644b ("drm/i915: Apply i915_request_skip() on submission") Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/work_items/13729 Signed-off-by: Sebastian Brzezinka Cc: stable@vger.kernel.org # v5.7+ Reviewed-by: Krzysztof Karas Reviewed-by: Andi Shyti Signed-off-by: Andi Shyti Link: https://lore.kernel.org/r/fe76921d35b6ae85aa651822726d0d9815aa5362.1776339012.git.sebastian.brzezinka@intel.com (cherry picked from commit 5ba54393dcd7adf75a9f39f5a933b1538349cad5) Signed-off-by: Tvrtko Ursulin Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/i915/gt/intel_reset.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/gpu/drm/i915/gt/intel_reset.c +++ b/drivers/gpu/drm/i915/gt/intel_reset.c @@ -137,7 +137,8 @@ void __i915_request_reset(struct i915_re rcu_read_lock(); /* protect the GEM context */ if (guilty) { i915_request_set_error_once(rq, -EIO); - __i915_request_skip(rq); + if (!i915_request_signaled(rq)) + __i915_request_skip(rq); banned = mark_guilty(rq); } else { i915_request_set_error_once(rq, -EAGAIN);