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Mon, 30 Oct 2017 20:50:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1509396607; bh=tccmR0NiooqLnGQrvu0DrzMxsOfjVTNy0f/jZ/hu2EE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=K2hjpoQpT9rZpGuuLTeyo7h2xDTmHQeFuaiNSrGiveUCnuotNxkaDpHYE1qyYeog4 mLct2zowN6/0JZGxko3xcevQ1l92T5UBZg6ywn6G3uzReJnz4neY2bCWb8hAJR69Ck U+4NqdqXbhAxgYGC1s/BxSPCFA5q05bU43EupIgU= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 99992607B5 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] Revert "gpio: set up initial state from .get_direction()" Date: Mon, 30 Oct 2017 15:49:59 -0500 Message-Id: <1509396602-1936-2-git-send-email-timur@codeaurora.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1509396602-1936-1-git-send-email-timur@codeaurora.org> References: <1509396602-1936-1-git-send-email-timur@codeaurora.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20171030_135028_589431_F05830A2 X-CRM114-Status: GOOD ( 15.37 ) 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 requested. --- 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