From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp-8fa9.mail.infomaniak.ch (smtp-8fa9.mail.infomaniak.ch [83.166.143.169]) (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 2814324169D for ; Wed, 24 Jun 2026 12:43:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=83.166.143.169 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782305030; cv=none; b=ubCx8xk074lEkZJqB/6ZvRRB4QXqGKw8QoMSkDkCE2Jp51n4B10m8v1OG5KKtWLx+nLYKxnfmWgxT4epdJXacQtxMNpx5Lho3aAk0GkUSP+yrRGlKL0GSwU0HeeUFbkxnHfJINeubkgb9G2OwbF5DtowFC556CyWpM6x6J5mLFw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782305030; c=relaxed/simple; bh=wHEP3T0JCOGOfR8/mhG8DF0emMo+OpOS1XpQXj0JKsg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=PEC9zOwE2d/Uyn7cdGuv6kfOGEOkH8ZfJ5curyQPg45IJQ6QJGKy/ZEgOBkD0Ujhb3/cOkCGeLmSKvxEuJpM0N5TBOFwUWlgMZ7xme4sPe2dwy0MUThUbk9ola0fKOxNybsvswiQaMdIuitAytOiojF+DpVhqJdb1R9RNKbvz1Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=gibson.sh; spf=pass smtp.mailfrom=gibson.sh; dkim=pass (2048-bit key) header.d=gibson.sh header.i=@gibson.sh header.b=ed3G/qnp; arc=none smtp.client-ip=83.166.143.169 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=gibson.sh Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gibson.sh Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gibson.sh header.i=@gibson.sh header.b="ed3G/qnp" Received: from smtp-3-0001.mail.infomaniak.ch (smtp-3-0001.mail.infomaniak.ch [10.4.36.108]) by smtp-4-3000.mail.infomaniak.ch (Postfix) with ESMTPS id 4glhSX4HVJzXgX for ; Wed, 24 Jun 2026 14:43:40 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gibson.sh; s=20260228; t=1782305020; bh=N2jcZfkZx8sHU1eydr66vjE0TAGI3mXPIcJNMYu/yg8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ed3G/qnpMIeyx4IpfwAhVad2MyHVErmNXsv3StEyz/hIPotDlobDuEL+5s2sXXoii vHGBbfFRw2pEUgYQcq+49nvG0i0tNk2xHXfll2bDSbYBsHOGtgdaO7T+m6EvwdsbTz uP3PbTrkTI7w4QeM4C3xNCAtM/qJ9k7zkqWCbroc2iBXK4R0Z/giOHfuhfMJN3rlxv 4dHviK+JF3athfFZp6WW/xYBC1jDMqymqeGm5W+/jEJBIZL64KgUE98hnym6XGzepu ClEohIjCw9QI3LDhiKZMSAyB0YzbT2lFBSPIJ7jbmmE4vEdppVjj8FAFEJy4kCSg09 WW0XZsGEoEINQ== Received: from unknown by smtp-3-0001.mail.infomaniak.ch (Postfix) with ESMTPA id 4glhSX1TkQzH8N for ; Wed, 24 Jun 2026 14:43:40 +0200 (CEST) Received: from unknown by spiderdemon.horst.lan (DragonFly Mail Agent v0.13); Wed, 24 Jun 2026 14:43:39 +0200 From: Daniel Gibson To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Jonathan Corbet , Shuah Khan , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= Cc: Daniel Gibson , "Mario Limonciello (AMD)" Subject: [PATCH 1/2] Documentation/arch/x86/amd-debugging: Add example for reset register Date: Wed, 24 Jun 2026 14:43:25 +0200 Message-ID: <20260624124326.746525-2-daniel@gibson.sh> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20260624124326.746525-1-daniel@gibson.sh> References: <20260624124326.746525-1-daniel@gibson.sh> Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Infomaniak-Routing: alpha The amd debugging documentation didn't state how to identify kernel log lines with information from the reset register about the cause of a previous random reboot. The added example rectifies this. Suggested-by: Mario Limonciello (AMD) Signed-off-by: Daniel Gibson --- Documentation/arch/x86/amd-debugging.rst | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/Documentation/arch/x86/amd-debugging.rst b/Documentation/arch/x86/amd-debugging.rst index d92bf59d62c7..3176a1240fee 100644 --- a/Documentation/arch/x86/amd-debugging.rst +++ b/Documentation/arch/x86/amd-debugging.rst @@ -366,3 +366,8 @@ There are 6 classes of reasons for the reboot: This information is read by the kernel at bootup and printed into the syslog. When a random reboot occurs this message can be helpful to determine the next component to debug. + +For example, if bit 19 was set, you will get a message like this in the log on +next bootup:: + + x86/amd: Previous system reset reason [0x00080000]: software wrote 0x6 to reset control register 0xCF9 -- 2.48.1