From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp-42ab.mail.infomaniak.ch (smtp-42ab.mail.infomaniak.ch [84.16.66.171]) (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 BA50E3DC4CC for ; Wed, 3 Jun 2026 03:11:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=84.16.66.171 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780456290; cv=none; b=LCjk37alXHbaZ4NVenUjYGX45k2Tou0TPwGT4tPGnWQZPp5cXrCNRILU7FJUpjzWvgiZqp4Q9dcnZ204CsUuhEKfayXZ3vm1v2Albj3UuztiT9xlFgD9Jeqs1LTZPFlY75aVtNva6d6BJJu828DeSUSeitgWNvgXM+YaEM8tWx4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780456290; c=relaxed/simple; bh=wHEP3T0JCOGOfR8/mhG8DF0emMo+OpOS1XpQXj0JKsg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=EgZC6z0h6q2oO4VEODS3Mvi165xg8iKX7YvcW2wWOg6V3uCt11CELHGpQCaLzZ/jvqrGRN3ZomGnbbxdFvSIRPPJ5U5NLfjM/nyzAHUY8fS51hrO4d3tkZbOJaqBa1BDEu0iyNnOm+7lDkon6XEKRffyI1zrr2ycvkjcaqWSj5Y= 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=MuYim8uu; arc=none smtp.client-ip=84.16.66.171 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="MuYim8uu" Received: from smtp-4-0001.mail.infomaniak.ch (smtp-4-0001.mail.infomaniak.ch [10.7.10.108]) by smtp-4-3000.mail.infomaniak.ch (Postfix) with ESMTPS id 4gVXlr5dSNz13sl for ; Wed, 3 Jun 2026 05:11:20 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gibson.sh; s=20260228; t=1780456280; bh=N2jcZfkZx8sHU1eydr66vjE0TAGI3mXPIcJNMYu/yg8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MuYim8uuBcNA3ExEQ+czq+vTrMahw3QhC9eWy8xB1d7CwKSmqe9lLhD3RCynsw+3b gSS59uGDMak/dykxwb+IH+9IsNUL/nN8CRV2tTPWvlOJ8h3gJjvFnYdQSOhO0Jr1Ey ZCcD5ZvExbdNKJOSaiXYP5mDVo3KZWEW4+o9vxh0D6D7r9D+/aT2TCNLx6rLu42yey TJrGURbAJDKQZmQ7wgrmmvps5OeW9Ouse9J21IpRAU0SqvQphzjmM0OdqsJ7ohY/Yn jmln6wVR4atMRycn/JawCS0Y03aejeP6v4WocuDCU+5rwSlkBKskRfuwylbzIL+ts7 R7VXL9ClgrGCQ== Received: from unknown by smtp-4-0001.mail.infomaniak.ch (Postfix) with ESMTPA id 4gVXlr2g1GzWrl for ; Wed, 3 Jun 2026 05:11:20 +0200 (CEST) Received: from unknown by spiderdemon.horst.lan (DragonFly Mail Agent v0.13); Wed, 03 Jun 2026 05:11:19 +0200 From: Daniel Gibson To: Shyam Sundar S K , Hans de Goede , =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= , platform-driver-x86@vger.kernel.org, linux-kernel@vger.kernel.org, Mario Limonciello Cc: Daniel Gibson Subject: [PATCH v3 RESEND 4/5] Documentation/arch/x86/amd-debugging: Add example for reset register Date: Wed, 3 Jun 2026 05:11:09 +0200 Message-ID: <20260603031110.345815-5-daniel@gibson.sh> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20260603031110.345815-1-daniel@gibson.sh> References: <20260603031110.345815-1-daniel@gibson.sh> Precedence: bulk X-Mailing-List: linux-kernel@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