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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,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 5CFF0C33C9E for ; Sat, 11 Jan 2020 10:01:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 307092084D for ; Sat, 11 Jan 2020 10:01:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578736912; bh=p+yC9RWYDnv+OJQJHw5r1dkCEKfrtAnQc5kuvhUQ+BU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=FUorHBqXBK9Fp1dMcKvI99jQ9Uvc0xET8CiBAsbk8sE+wPFX7Vvqi0XI/9Bq3vYEy AR2Leq2KDSTs6iJ+hs48QSW2OEipebG6dzgzpkqviBmiNFHNqRZh2pSxUtBhQZuYdE WkpSt6Z3hqgmgcyeXCVtHDHvA+wZGH381VReKYhA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729466AbgAKKBv (ORCPT ); Sat, 11 Jan 2020 05:01:51 -0500 Received: from mail.kernel.org ([198.145.29.99]:59582 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729171AbgAKKBt (ORCPT ); Sat, 11 Jan 2020 05:01:49 -0500 Received: from localhost (unknown [62.119.166.9]) (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 B19EB2077C; Sat, 11 Jan 2020 10:01:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578736909; bh=p+yC9RWYDnv+OJQJHw5r1dkCEKfrtAnQc5kuvhUQ+BU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SYaPBiqvqLpejMFT7Kozah5S3OA9F32xdMqnQLUg0T8FEpU7iFOA3HdoeZIZZ/0Nu sFNciPmdnFJ8tuXA3bG26fSPLDjATGID0ZTPnOzL4zCvNpN451A9gNaXNAx9+RY+d9 9J5NOLwZmQQZwkdb7gqKZr/xf0waiDcezDgkSowI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Linus Walleij , Russell King , Bartosz Golaszewski Subject: [PATCH 4.9 29/91] gpiolib: fix up emulated open drain outputs Date: Sat, 11 Jan 2020 10:49:22 +0100 Message-Id: <20200111094855.400352089@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200111094844.748507863@linuxfoundation.org> References: <20200111094844.748507863@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 From: Russell King commit 256efaea1fdc4e38970489197409a26125ee0aaa upstream. gpiolib has a corner case with open drain outputs that are emulated. When such outputs are outputting a logic 1, emulation will set the hardware to input mode, which will cause gpiod_get_direction() to report that it is in input mode. This is different from the behaviour with a true open-drain output. Unify the semantics here. Cc: Suggested-by: Linus Walleij Signed-off-by: Russell King Signed-off-by: Bartosz Golaszewski Signed-off-by: Greg Kroah-Hartman --- drivers/gpio/gpiolib.c | 8 ++++++++ 1 file changed, 8 insertions(+) --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -188,6 +188,14 @@ int gpiod_get_direction(struct gpio_desc chip = gpiod_to_chip(desc); offset = gpio_chip_hwgpio(desc); + /* + * Open drain emulation using input mode may incorrectly report + * input here, fix that up. + */ + if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) && + test_bit(FLAG_IS_OUT, &desc->flags)) + return 0; + if (!chip->get_direction) return status;