From patchwork Fri Jan 24 09:28:09 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 1228719 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-rtc-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=default header.b=iwZv9b0A; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 483vTQ23bcz9sNF for ; Fri, 24 Jan 2020 20:48:10 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733025AbgAXJsJ (ORCPT ); Fri, 24 Jan 2020 04:48:09 -0500 Received: from mail.kernel.org ([198.145.29.99]:48128 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730051AbgAXJsJ (ORCPT ); Fri, 24 Jan 2020 04:48:09 -0500 Received: from localhost (unknown [145.15.244.15]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 613412087E; Fri, 24 Jan 2020 09:48:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579859288; bh=RsZ49+HuVXrU/JY3Ejeo3KXvJigAnXjCknahaYv5sjA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iwZv9b0AlOs6iMd/ezazixvxMXIYIphh74dYvkr5+gLSWyPqyN3IpCREidYlAlulL NyKlgrxEYZfnjcshJNJTBciSBJxQjAQ1JbkjVEIBvsokNTCn+bdxphLklm+gLsZDfD Kk/zPK1he8BVW2D3UHeN9IvAa1DQKHF31rBmexd4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alexandre Belloni , Alessandro Zummo , Sylvain Chouleur , Patrick McDermott , linux-rtc@vger.kernel.org, Eric Wong , Sasha Levin Subject: [PATCH 4.14 071/343] rtc: cmos: ignore bogus century byte Date: Fri, 24 Jan 2020 10:28:09 +0100 Message-Id: <20200124092929.142447271@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200124092919.490687572@linuxfoundation.org> References: <20200124092919.490687572@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: linux-rtc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rtc@vger.kernel.org From: Eric Wong [ Upstream commit 2a4daadd4d3e507138f8937926e6a4df49c6bfdc ] Older versions of Libreboot and Coreboot had an invalid value (`3' in my case) in the century byte affecting the GM45 in the Thinkpad X200. Not everybody's updated their firmwares, and Linux <= 4.2 was able to read the RTC without problems, so workaround this by ignoring invalid values. Fixes: 3c217e51d8a272b9 ("rtc: cmos: century support") Cc: Alexandre Belloni Cc: Alessandro Zummo Cc: Sylvain Chouleur Cc: Patrick McDermott Cc: linux-rtc@vger.kernel.org Signed-off-by: Eric Wong Signed-off-by: Alexandre Belloni Signed-off-by: Sasha Levin --- drivers/rtc/rtc-mc146818-lib.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/rtc/rtc-mc146818-lib.c b/drivers/rtc/rtc-mc146818-lib.c index 2f1772a358ca5..18a6f15e313d8 100644 --- a/drivers/rtc/rtc-mc146818-lib.c +++ b/drivers/rtc/rtc-mc146818-lib.c @@ -82,7 +82,7 @@ unsigned int mc146818_get_time(struct rtc_time *time) time->tm_year += real_year - 72; #endif - if (century) + if (century > 20) time->tm_year += (century - 19) * 100; /*