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,URIBL_BLOCKED,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 210B4C169C4 for ; Mon, 11 Feb 2019 15:47:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E520D21855 for ; Mon, 11 Feb 2019 15:47:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1549900077; bh=6dRenVydqK1sbvsRWpEJMof+y21YdYzuAphinzH/GdI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=XdCfKcH/BMBQF+XsFp5QH0sbxpTQSfoe2XWsqM+HDBFQM9JLdlerHUXNK/PioBOqu dy/hC1iUCPm+ETKAk9tACyJMSxpXmrDyrwPTwDkBticXNtd/76HZkO/Pr4ZGolPfbl U5ovhyQQ0I3mjPxiCP+jDQhQhj6+wNOJpIXLNCEE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731787AbfBKPru (ORCPT ); Mon, 11 Feb 2019 10:47:50 -0500 Received: from mail.kernel.org ([198.145.29.99]:52468 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732190AbfBKOlP (ORCPT ); Mon, 11 Feb 2019 09:41:15 -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 17FEC2081B; Mon, 11 Feb 2019 14:41:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1549896074; bh=6dRenVydqK1sbvsRWpEJMof+y21YdYzuAphinzH/GdI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=R0Esa11OCX+v3LYpOkF/V2U6dQkbMQWm+jh4XAXgxWbofRaI0wkbCafX3D6AqHrxq pSFN22GIKIEZr+xuaN3uyu0cfrwBe3Y+CP/VlcC8Q0q/1PKVi+2LSNjpUqs76ha2DD yA8MEC97QbpAEWQW06IqnO5IenZ7vabzwHc27feY= 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 4.19 065/313] ACPI: SPCR: Consider baud rate 0 as preconfigured state Date: Mon, 11 Feb 2019 15:15:45 +0100 Message-Id: <20190211141858.204121706@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190211141852.749630980@linuxfoundation.org> References: <20190211141852.749630980@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: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 4.19-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