From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 180E4C169C4 for ; Mon, 11 Feb 2019 14:24:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CF6F5214DA for ; Mon, 11 Feb 2019 14:24:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1549895082; bh=w5WSb/uEfpoz2iAjZ2JSfX3Bn7DGypH0y3LbchJEjzU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=lE8aW6ADOj7obHiQ12A5G+LkVfFX96pouvb5mqh9XVtMmxXk0jUc6/0gAi70iqMQL 9f+z0PRwr68Eoe2a6STxgGKQE1bqeFF9egynQksVoXTbY1fwBwufwjTGv1p9vfdoyU 4oPPiyaejCvqSfDZ49jAFGPUgo6ijWPk2DdNpzbc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729257AbfBKOYl (ORCPT ); Mon, 11 Feb 2019 09:24:41 -0500 Received: from mail.kernel.org ([198.145.29.99]:57908 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729242AbfBKOYi (ORCPT ); Mon, 11 Feb 2019 09:24:38 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (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 E70642075C; Mon, 11 Feb 2019 14:24:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1549895078; bh=w5WSb/uEfpoz2iAjZ2JSfX3Bn7DGypH0y3LbchJEjzU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wyP3QgtFBNYwhf+3oqn8OWBSnF9czKrgB3Qna6mozrwatCmhG5KDUoc+OJbDk6lxT 9NzkkEKx/zpSp4iBP5me+9/G/GMYruXDNCLO+KGTH0Hoaeo/D5310Dq1HPInK8qATb k+XG/gZAgVqdPqKLbKqmnEYUJJPmzSqUJfJFJ41Q= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Andy Shevchenko , Prarit Bhargava , "Rafael J. Wysocki" , Sasha Levin Subject: [PATCH 4.20 077/352] ACPI: SPCR: Consider baud rate 0 as preconfigured state Date: Mon, 11 Feb 2019 15:15:04 +0100 Message-Id: <20190211141850.947607772@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190211141846.543045703@linuxfoundation.org> References: <20190211141846.543045703@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.20-stable review patch. If anyone has any objections, please let me know. ------------------ [ Upstream commit b413b1abeb21b4a152c0bf8d1379efa30759b6e3 ] Since SPCR 1.04 [1] the baud rate of 0 means a preconfigured state of UART. Assume firmware or bootloader configures console correctly. [1]: https://docs.microsoft.com/en-us/windows-hardware/drivers/serports/serial-port-console-redirection-table Signed-off-by: Andy Shevchenko Reviewed-by: Prarit Bhargava Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin --- drivers/acpi/spcr.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/acpi/spcr.c b/drivers/acpi/spcr.c index 9d52743080a4..c336784d0bcb 100644 --- a/drivers/acpi/spcr.c +++ b/drivers/acpi/spcr.c @@ -148,6 +148,13 @@ int __init acpi_parse_spcr(bool enable_earlycon, bool enable_console) } switch (table->baud_rate) { + case 0: + /* + * SPCR 1.04 defines 0 as a preconfigured state of UART. + * Assume firmware or bootloader configures console correctly. + */ + baud_rate = 0; + break; case 3: baud_rate = 9600; break; @@ -196,6 +203,10 @@ int __init acpi_parse_spcr(bool enable_earlycon, bool enable_console) * UART so don't attempt to change to the baud rate state * in the table because driver cannot calculate the dividers */ + baud_rate = 0; + } + + if (!baud_rate) { snprintf(opts, sizeof(opts), "%s,%s,0x%llx", uart, iotype, table->serial_port.address); } else { -- 2.19.1