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 A322D27281E for ; Sat, 9 May 2026 01:31:16 +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=1778290278; cv=none; b=XEgm/jg+qQ3WRKahTWYTB0/ldYD/7iIeM3ZzlKLB58f/CqeDGAQ96BIVQusBMTgTFrsVDxs32vKjo1C8nf/x/V4HYVk9N6GZABZIQPEUDoQZ39P8kinRdAT29UQJuhJd5CBqw4N18Y9aFnVkKDrd2bqHDevXiZvU15xf2V0HABg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778290278; c=relaxed/simple; bh=1yu+/UM6Y0GoI7lTTWpwIsOj8noQkvZeDhVOAffQz28=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=D29TlZFPzr6rU9ErDG1TPUDBizk0eVj9/Q9uQdt1EQy33hmY5gK7RrwD+GISd+uu2WNMQfXhG55JaVHzvs0oyn6ZywksrZxCZENA07Uc+garbgQ1A4KPmdx+U13QLEFlTxHp1JHrNYEeaPGpwbtLfS6vGp+GVo6wKCWeRzhWUYA= 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=Kum6yGWT; 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="Kum6yGWT" Received: from smtp-4-0001.mail.infomaniak.ch (unknown [IPv6:2001:1600:7:10::a6c]) by smtp-4-3000.mail.infomaniak.ch (Postfix) with ESMTPS id 4gC7jn3SqczY3M for ; Sat, 9 May 2026 03:31:09 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gibson.sh; s=20260228; t=1778290269; bh=a+WRQSJV9hBwuS2Du1AmZQPBdJRpx+moR5xxxAEURRk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Kum6yGWTUD6izp5cmKheJ7ciQZMN75B3AA5RX751ekqep6o2b1KJcO6ZCdKdsUVv/ mE9oYKF9KO6fQRONlaoNaO/a8OTjMn7TNBFXA6AaHqe9Q0kTUJAvjSpM9nufRPK5x/ zp8bK6ZoXQJ7UaTNNUmXphMh9tEZ7RqoEeQUijM494X8GVzauIyKlLYwjn9p/JdXtv 5Ra74mD3CCtTwEmHz/Z1V7Z86vREVV41MBDSXnOFxuCmjRn9rP6Oz9ZM1Qwoat4f+M OX5WoTcE21liUkZiEd+aALgIx/ACEzbpi4kRo5Pa8pTPQ4hFZZC7LrO3navdghR7b/ GUsfQ72TRA2kg== Received: from unknown by smtp-4-0001.mail.infomaniak.ch (Postfix) with ESMTPA id 4gC7jn0MD4zg3L for ; Sat, 9 May 2026 03:31:09 +0200 (CEST) Received: from unknown by spiderdemon.horst.lan (DragonFly Mail Agent v0.13); Sat, 09 May 2026 03:31:08 +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 Cc: Daniel Gibson Subject: [PATCH v2 4/5] Documentation/arch/x86/amd-debugging: Add example for reset register Date: Sat, 9 May 2026 03:31:03 +0200 Message-ID: <20260509013105.816339-5-daniel@gibson.sh> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20260509013105.816339-1-daniel@gibson.sh> References: <20260509013105.816339-1-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 To me it wasn't clear how I get the information stored in the reset register, or how to identify the messages in the syslog mentioned there. Mario Limonciello sent me an example line which illustrates what to look for and I added it to the AMD debugging documentation, with a short explanation. 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