From patchwork Tue Nov 7 23:07:33 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Timur Tabi X-Patchwork-Id: 10047359 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 9FE9560360 for ; Tue, 7 Nov 2017 23:08:11 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 92FA629350 for ; Tue, 7 Nov 2017 23:08:11 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 86B8929426; Tue, 7 Nov 2017 23:08:11 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,RCVD_IN_DNSWL_MED autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [65.50.211.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 077BD29350 for ; 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Tue, 7 Nov 2017 23:07:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1510096062; bh=Hj22sMOkAJ0BVIXdT0BA8UVtiI+xD8O6wWbasJPcTCs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=dBFezDM0onoi2ZDxPTwhm+q+hxV+/IkX6MUKfz2y1gm0FHoEXJzRev2YzC9gebAaa yipeWkC2xNbFsXGe0S3ctu78kj8ZNwYII/cEbSgGDG36QH+zvHRY1qoP+Mfls8wNUS Ph9lGYtKAjxQG4mfWP2lN1bgjCWudeSox/5Tv+jw= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 7D8746079D Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=timur@codeaurora.org From: Timur Tabi To: linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-gpio@vger.kernel.org, Linus Walleij , Andy Shevchenko , Mika Westerberg , thierry.reding@gmail.com, Stephen Boyd , david.brown@linaro.org, andy.gross@linaro.org, Bjorn Andersson Subject: [PATCH 1/4] [v2] Revert "gpio: set up initial state from .get_direction()" Date: Tue, 7 Nov 2017 17:07:33 -0600 Message-Id: <1510096056-13765-2-git-send-email-timur@codeaurora.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1510096056-13765-1-git-send-email-timur@codeaurora.org> References: <1510096056-13765-1-git-send-email-timur@codeaurora.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20171107_150804_167440_243AFDC0 X-CRM114-Status: GOOD ( 15.14 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: timur@codeaurora.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP This reverts commit 72d3200061776264941be1b5a9bb8e926b3b30a5. We cannot blindly query the direction of all GPIOs when the pins are first registered. The get_direction callback normally triggers a read/write to hardware, but we shouldn't be touching the hardware for an individual GPIO until after it's been properly claimed. Signed-off-by: Timur Tabi --- drivers/gpio/gpiolib.c | 31 +++++++------------------------ 1 file changed, 7 insertions(+), 24 deletions(-) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index eb80dac4e26a..60553af4c004 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -1221,31 +1221,14 @@ int gpiochip_add_data(struct gpio_chip *chip, void *data) struct gpio_desc *desc = &gdev->descs[i]; desc->gdev = gdev; - /* - * REVISIT: most hardware initializes GPIOs as inputs - * (often with pullups enabled) so power usage is - * minimized. Linux code should set the gpio direction - * first thing; but until it does, and in case - * chip->get_direction is not set, we may expose the - * wrong direction in sysfs. - */ - - if (chip->get_direction) { - /* - * If we have .get_direction, set up the initial - * direction flag from the hardware. - */ - int dir = chip->get_direction(chip, i); - if (!dir) - set_bit(FLAG_IS_OUT, &desc->flags); - } else if (!chip->direction_input) { - /* - * If the chip lacks the .direction_input callback - * we logically assume all lines are outputs. - */ - set_bit(FLAG_IS_OUT, &desc->flags); - } + /* REVISIT: most hardware initializes GPIOs as inputs (often + * with pullups enabled) so power usage is minimized. Linux + * code should set the gpio direction first thing; but until + * it does, and in case chip->get_direction is not set, we may + * expose the wrong direction in sysfs. + */ + desc->flags = !chip->direction_input ? (1 << FLAG_IS_OUT) : 0; } #ifdef CONFIG_PINCTRL