From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794411065; b=lbyvs4BfhoXtKh8Ork933UfD1HkR4xxIoKGKn1OgPVmNIg+jM7oXByRMEjZuDMuIxF2V PZzGaBjTXqFNk5bl5fM5tHkgJQ+7K6jxNs+CjQXaX9jRl9ZvAqj1zPN/s08TpqqJsOxtY QclJqYi9aFcMU1Cf3c18p+hRRrpfLHaxuR1MYIiY7nF8MtSgb0/Ez1Pb/JhsBB01qlW6T AGA8/wgbap1ICDb11sQ+1826CQzptR1Z0Uc/F9pDiKPjYmkOxBeki3lrRR3uyir+Zrhu3 x01X4qBb3LDAkXWYPqC2wTIXMhzfC83PLVOzpLTvCrE8kqF96AlkamRR6bKo7sW36OA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794411065; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=Y/1xWfSz8iZXTqpxupGdkaIlKjxLc5Z5iZMubleV7/k=; b=TmCSX+RfUKfY1aFHqU6K7and8KVJ8IPF1rRZ3xq/3uf9uW9cHY0H5D/Y17q6oLWLci+u gESrlkAh4qY3q8V6qeCezlBsVx6TxCChJb+bCtdEAUdy3zilB9NOuhozqSyIg/scZj59y BQy0JszOTfFnjFOw+M03HOfAZfCBeizIFNQjnHqUnoNARmSPfH2q7z1a6yJWgsP3gmMC0 whmtuurp3WfsBQ4ShP+l1dzcJMki6X+8KEgtX7cD5FR8aOunGF4Mm2qAL2oCyRs7gRUBx XFyE/xFNLvFJocidQRCKzt7ru3yhfDHEWKMSuVNruxNZFp/lOkQ4f44sTQEsk6qW0YA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b="O/G+e327"; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 98AF7606A32E for ; Wed, 11 Nov 2026 15:31:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=O/G+e327 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 82A9D1F00A06; Wed, 11 Nov 2026 15:31:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794411065; bh=Y/1xWfSz8iZXTqpxupGdkaIlKjxLc5Z5iZMubleV7/k=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=O/G+e327uTs3zHpD441ekKRq4SbXaHLLB+/LMNss25H+gwvC4C65gFq9po5xDPIOY glwaW7GadK02qc6O3+VxIKA7FtElVSc9/U/c4ZiE0/MMD2xWQnVpF90nBDa5kHoi3U 7SQz8C2u/hTBn1i5HqnygoSbu98gxtS6ZK0tz7ThZVc3B5EVZOSI4cYDGamkPWqV7R QBAKWbwvUZZku75+MbfkXbHYCoPehP1uEwC38S8/lr42IJSe4rsqRU6SDUF+A0U5M1 w24MzIj2+HWTGSOvFq8ZKw50BaJwB2c3unEwFhZscTsOD5oH21JW+Jjzo90x8bWu6J pLxkbsH2ypzPg== From: Sasha Levin To: stable@vger.kernel.org Cc: Adrian Ambrozewicz , Kent Gibson , Bartosz Golaszewski , Sasha Levin Subject: [PATCH 6.1.y] gpiolib: cdev: don't set GPIOD_FLAG_IS_OUT Date: Wed, 11 Nov 2026 10:31:03 -0500 Message-ID: <20261111153049.2690681-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261107055105-failed-6.1-974d2712cb15@kernel.org> References: <20261107055105-failed-6.1-974d2712cb15@kernel.org> X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Adrian Ambrozewicz [ Upstream commit 974d2712cb15014019595799b3ed68fef5fe9695 ] When a line is requested or reconfigured through the v2 uAPI, gpio_v2_line_config_flags_to_desc_flags() copies the requested configuration into the descriptor flags, GPIOD_FLAG_IS_OUT included, before gpiod_direction_input_nonotify() or gpiod_direction_output_nonotify() asks the driver for the direction. If the driver refuses, for instance with -EOPNOTSUPP from .direction_input() for a line that can only be an output, the ioctl fails but the flag keeps the refused direction. gpiod_free_commit() does not touch GPIOD_FLAG_IS_OUT, so this outlives the failed request, and GPIO_V2_GET_LINEINFO_IOCTL reports the line as an input while the hardware still drives it, until a request without direction flags makes gpiod_request_commit() read the direction back from the driver: GPIO_V2_GET_LINE_IOCTL, line 0, input: -EOPNOTSUPP GPIO_V2_GET_LINEINFO_IOCTL, line 0: input GPIO_V2_GET_LINE_IOCTL, line 0, no direction: ok GPIO_V2_GET_LINEINFO_IOCTL, line 0: output GPIO_V2_LINE_SET_CONFIG_IOCTL updates the flags in the same order. There the line stays requested, and since commit 92ac7de3175e ("gpiolib: don't allow setting values on input lines") GPIO_V2_LINE_SET_VALUES_IOCTL on it then fails with -EPERM, though the line is still an output. A line whose driver refuses to make it an output is likewise reported as one. gpiod_direction_input_nonotify() and gpiod_direction_output_nonotify() set or clear GPIOD_FLAG_IS_OUT themselves once the driver has accepted the direction, emulated open drain and open source included, and nothing between the copy and those calls reads the flag. Leave it to them, as the v1 uAPI already does. The other flags that the helper copies stay as they are. Active low, drive and bias are what gpiod_direction_*() applies, drive and bias possibly before the driver refuses the direction; edges and event clock are the character device's own. None of them is read back from the driver, so there is no earlier state that is more accurate to go back to. A failed request releases the line, which clears them, and a failed reconfiguration leaves the line, like the lines before it, with what was applied up to the failure. Reproduced under QEMU with a test GPIO chip whose line 0 refuses input and line 1 refuses output: both refused requests and both refused reconfigurations leave the line info with the refused direction, and setting the value of the reconfigured output fails with -EPERM. With this change the line info shows the direction of the hardware in all four cases and setting the value works. First seen on real hardware with v6.12. Fixes: 3c0d9c635ae2 ("gpiolib: cdev: support GPIO_V2_GET_LINE_IOCTL and GPIO_V2_LINE_GET_VALUES_IOCTL") Cc: stable@vger.kernel.org Assisted-by: LLM Signed-off-by: Adrian Ambrozewicz Reviewed-by: Kent Gibson Link: https://patch.msgid.link/20261016-gpiolib-cdev-direction-v2-1-aambrozewicz@nvidia.com Signed-off-by: Bartosz Golaszewski [ sashal: adapted GPIOD_FLAG_IS_OUT and &flags references to FLAG_IS_OUT and flagsp ] Signed-off-by: Sasha Levin --- drivers/gpio/gpiolib-cdev.c | 5 ----- 1 file changed, 5 deletions(-) diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c index 5d4646f0baacd..c3ca14d4b22cf 100644 --- a/drivers/gpio/gpiolib-cdev.c +++ b/drivers/gpio/gpiolib-cdev.c @@ -1375,11 +1375,6 @@ static void gpio_v2_line_config_flags_to_desc_flags(u64 flags, assign_bit(FLAG_ACTIVE_LOW, flagsp, flags & GPIO_V2_LINE_FLAG_ACTIVE_LOW); - if (flags & GPIO_V2_LINE_FLAG_OUTPUT) - set_bit(FLAG_IS_OUT, flagsp); - else if (flags & GPIO_V2_LINE_FLAG_INPUT) - clear_bit(FLAG_IS_OUT, flagsp); - assign_bit(FLAG_EDGE_RISING, flagsp, flags & GPIO_V2_LINE_FLAG_EDGE_RISING); assign_bit(FLAG_EDGE_FALLING, flagsp, -- 2.53.0