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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,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 12CAEC76186 for ; Mon, 29 Jul 2019 19:51:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D0D8520C01 for ; Mon, 29 Jul 2019 19:51:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564429865; bh=7vje2itFpn752mX8Yf8zqkH//JVLSqFrMo8kkfuZFns=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=JuDAhCO71BeQnlb3IluRTvVtg9pp4tO3fR+cLMpF6RjdijcjnCsYwuMFM6peXn4UU F/n8Q0+VMia2Yjpko65ue1HPOnB6ZI4mHhI6icMzz6q8qHPauEWdsrznLNWsgvYVZx 7Xoh40ZTrt6/Jy2gnbBdiTRqjZ77H2ncJivkvOkU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390702AbfG2TvE (ORCPT ); Mon, 29 Jul 2019 15:51:04 -0400 Received: from mail.kernel.org ([198.145.29.99]:42106 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2403829AbfG2TvA (ORCPT ); Mon, 29 Jul 2019 15:51:00 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.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 B81592054F; Mon, 29 Jul 2019 19:50:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564429859; bh=7vje2itFpn752mX8Yf8zqkH//JVLSqFrMo8kkfuZFns=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=L0pfKsYlbWq0pDBWyTPA5kUx0oSsF13a3Ks2z6YwJYjiaQQFVmZeaxyXtuohAWm7X UD1PNEPfxoSuBG38WgGY2k/RV6QM4OB3o6GA7tDL3LTRD0DMtGudtrEXUZJN7+rOqw DKSEnulUU04YoxVS49Nvr376xJK0IUFBGQEcm084= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Stefan Roese , Mika Westerberg , Andy Shevchenko , Yegor Yefremov , Giulio Benetti , Sasha Levin Subject: [PATCH 5.2 079/215] serial: mctrl_gpio: Check if GPIO property exisits before requesting it Date: Mon, 29 Jul 2019 21:21:15 +0200 Message-Id: <20190729190753.521871557@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190729190739.971253303@linuxfoundation.org> References: <20190729190739.971253303@linuxfoundation.org> User-Agent: quilt/0.66 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 [ Upstream commit d99482673f950817b30caf3fcdfb31179b050ce1 ] This patch adds a check for the GPIOs property existence, before the GPIO is requested. This fixes an issue seen when the 8250 mctrl_gpio support is added (2nd patch in this patch series) on x86 platforms using ACPI. Here Mika's comments from 2016-08-09: " I noticed that with v4.8-rc1 serial console of some of our Broxton systems does not work properly anymore. I'm able to see output but input does not work. I bisected it down to commit 4ef03d328769eddbfeca1f1c958fdb181a69c341 ("tty/serial/8250: use mctrl_gpio helpers"). The reason why it fails is that in ACPI we do not have names for GPIOs (except when _DSD is used) so we use the "idx" to index into _CRS GPIO resources. Now mctrl_gpio_init_noauto() goes through a list of GPIOs calling devm_gpiod_get_index_optional() passing "idx" of 0 for each. The UART device in Broxton has following (simplified) ACPI description: Device (URT4) { ... Name (_CRS, ResourceTemplate () { GpioIo (Exclusive, PullDefault, 0x0000, 0x0000, IoRestrictionOutputOnly, "\\_SB.GPO0", 0x00, ResourceConsumer) { 0x003A } GpioIo (Exclusive, PullDefault, 0x0000, 0x0000, IoRestrictionOutputOnly, "\\_SB.GPO0", 0x00, ResourceConsumer) { 0x003D } }) In this case it finds the first GPIO (0x003A which happens to be RX pin for that UART), turns it into GPIO which then breaks input for the UART device. This also breaks systems with bluetooth connected to UART (those typically have some GPIOs in their _CRS). Any ideas how to fix this? We cannot just drop the _CRS index lookup fallback because that would break many existing machines out there so maybe we can limit this to only DT enabled machines. Or alternatively probe if the property first exists before trying to acquire the GPIOs (using device_property_present()). " This patch implements the fix suggested by Mika in his statement above. Signed-off-by: Stefan Roese Reviewed-by: Mika Westerberg Reviewed-by: Andy Shevchenko Tested-by: Yegor Yefremov Cc: Mika Westerberg Cc: Andy Shevchenko Cc: Yegor Yefremov Cc: Greg Kroah-Hartman Cc: Giulio Benetti Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/tty/serial/serial_mctrl_gpio.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/drivers/tty/serial/serial_mctrl_gpio.c b/drivers/tty/serial/serial_mctrl_gpio.c index 39ed56214cd3..2b400189be91 100644 --- a/drivers/tty/serial/serial_mctrl_gpio.c +++ b/drivers/tty/serial/serial_mctrl_gpio.c @@ -12,6 +12,7 @@ #include #include #include +#include #include "serial_mctrl_gpio.h" @@ -116,6 +117,19 @@ struct mctrl_gpios *mctrl_gpio_init_noauto(struct device *dev, unsigned int idx) for (i = 0; i < UART_GPIO_MAX; i++) { enum gpiod_flags flags; + char *gpio_str; + bool present; + + /* Check if GPIO property exists and continue if not */ + gpio_str = kasprintf(GFP_KERNEL, "%s-gpios", + mctrl_gpios_desc[i].name); + if (!gpio_str) + continue; + + present = device_property_present(dev, gpio_str); + kfree(gpio_str); + if (!present) + continue; if (mctrl_gpios_desc[i].dir_out) flags = GPIOD_OUT_LOW; -- 2.20.1