From patchwork Fri Dec 4 16:47:36 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 11951943 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=-17.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,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 5BD96C2BB48 for ; Fri, 4 Dec 2020 16:48:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2D07E22B2A for ; Fri, 4 Dec 2020 16:48:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730834AbgLDQs3 (ORCPT ); Fri, 4 Dec 2020 11:48:29 -0500 Received: from mail.kernel.org ([198.145.29.99]:57444 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729262AbgLDQs3 (ORCPT ); Fri, 4 Dec 2020 11:48:29 -0500 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (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 712F122AED; Fri, 4 Dec 2020 16:47:48 +0000 (UTC) Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=why.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94) (envelope-from ) id 1klEFG-00G234-Mr; Fri, 04 Dec 2020 16:47:46 +0000 From: Marc Zyngier To: linux-usb@vger.kernel.org, linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Linus Walleij , Bartosz Golaszewski , Johan Hovold , Greg Kroah-Hartman , kernel-team@android.com Subject: [PATCH 1/4] gpiolib: cdev: Flag invalid GPIOs as used Date: Fri, 4 Dec 2020 16:47:36 +0000 Message-Id: <20201204164739.781812-2-maz@kernel.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201204164739.781812-1-maz@kernel.org> References: <20201204164739.781812-1-maz@kernel.org> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: linux-usb@vger.kernel.org, linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org, linus.walleij@linaro.org, bgolaszewski@baylibre.com, johan@kernel.org, gregkh@linuxfoundation.org, kernel-team@android.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org When reporting the state of a GPIO to userspace, we never check for the actual validity of the line, meaning we report invalid lines as being usable. A subsequent request will fail though, which is an inconsistent behaviour from a userspace perspective. Instead, let's check for the validity of the line and report it as used if it is invalid. This allows a tool such as gpioinfo to report something sensible: gpiochip3 - 4 lines: line 0: unnamed unused input active-high line 1: unnamed kernel input active-high [used] line 2: unnamed kernel input active-high [used] line 3: unnamed unused input active-high In this example, lines 1 and 2 are invalid, and cannot be used by userspace. Signed-off-by: Marc Zyngier --- drivers/gpio/gpiolib-cdev.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c index e9faeaf65d14..a0fcb4ccaa02 100644 --- a/drivers/gpio/gpiolib-cdev.c +++ b/drivers/gpio/gpiolib-cdev.c @@ -1910,6 +1910,7 @@ static void gpio_desc_to_lineinfo(struct gpio_desc *desc, test_bit(FLAG_USED_AS_IRQ, &desc->flags) || test_bit(FLAG_EXPORT, &desc->flags) || test_bit(FLAG_SYSFS, &desc->flags) || + !gpiochip_line_is_valid(gc, info->offset) || !ok_for_pinctrl) info->flags |= GPIO_V2_LINE_FLAG_USED;