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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_GIT autolearn=ham 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 BF6C7C282C8 for ; Mon, 28 Jan 2019 17:04:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8384421741 for ; Mon, 28 Jan 2019 17:04:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548695099; bh=ajiJ1ou3XvKupkUF6ZQ+3ur2tYE1pNusbxmeztoHYC0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=WQi8F7nRWMIRyYNd+3kyqyAH2lcj9GN3pNt6tmOymDu7A3r6FotIH29o/n3JgHwPX TOMCPrc4HO7Ptzc/UHQLY66J+842GSHWnWG1wSHLvt+TjCHQkwylO49+J/RpnXpFh3 g43hx3kTD3W8rwtbBWonE0y3GMKK5HoMq5brvH6w= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387736AbfA1RE5 (ORCPT ); Mon, 28 Jan 2019 12:04:57 -0500 Received: from mail.kernel.org ([198.145.29.99]:42612 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387477AbfA1QNs (ORCPT ); Mon, 28 Jan 2019 11:13:48 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3FA5F2175B; Mon, 28 Jan 2019 16:13:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548692028; bh=ajiJ1ou3XvKupkUF6ZQ+3ur2tYE1pNusbxmeztoHYC0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1+DqV2UQ4gqKbgqnwLG1jDKV9RrABVmfXS0N/4iJZzQWrecUakT2TaVG5LW7dyiN2 wJwOiUxeN26iG1oPTOAyaqu4tNjDuwHXsHZmd25ewOqZDI1Itgq4mVr5t7x6U4rStn E1V337hp+mZMOXmCICr+sF7tKKZnegMXfABV//hc= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Andy Shevchenko , "Rafael J . Wysocki" , Sasha Levin , linux-acpi@vger.kernel.org Subject: [PATCH AUTOSEL 4.14 043/170] ACPI: SPCR: Consider baud rate 0 as preconfigured state Date: Mon, 28 Jan 2019 11:09:53 -0500 Message-Id: <20190128161200.55107-43-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190128161200.55107-1-sashal@kernel.org> References: <20190128161200.55107-1-sashal@kernel.org> MIME-Version: 1.0 X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Andy Shevchenko [ 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 324b35bfe781..f567fa5f0148 100644 --- a/drivers/acpi/spcr.c +++ b/drivers/acpi/spcr.c @@ -148,6 +148,13 @@ int __init parse_spcr(bool earlycon) } 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 parse_spcr(bool earlycon) * 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