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=1794063517; b=1GWFWaM7Amrf5rWRAdENUp9/uLIczGCfbAt3JKCFp0zEMlWqkCwnlklqHY5j8pcY8Tsz ylqxphfuW30W1gkJlHk4ruiFYUe4bFm72cvyBuKZRtPQgsi4X1aI3MAfK4bWBSEOqJM/W wJmys6F/laPPCRTEyL7BNKYHEqid6rqMhibkwcqFPshGR+1cw40KZk0Hekwm5p8Xczt96 ZDqSPCWaOOVs/i4B+O/VQ1cTiZF+Z+lVIXpyL0+1vM2t8rz0Nhd+qCWBQyByiNXCMOYOC B6scZbFLAbnG/IPTMZLvLfpUxG7eKhOmvRmqib7ltkwEUnFgWXYI3YxfWNoW3Uf8uOA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794063517; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=d6zjBtVg5oO1t5dBT9zeHbAkGkx8g5x/6dUn6S/Uk8A=; b=3q279KAgLhpzK3bV6yZB6B+gwVls2UIRSZmONFVpEKCiYhbOrYJiR9Xqb6GEcpvwIbEu eEHGzKQu0QnmWlsWRz9rea+IXE+AAdeHwbu6tTLbCqGcSG3/ipMuJWh972jPITKUUjTJy 15bHK/VAaPlC+Fx0Gi+cXu7l63aL2AMLzS/bk1hn35vVdI8FUI3P/DsjfzfvSn5gcH6qm l3So7ivzlmmZgoWCVePqUVOF6Hp3dWG4O2dLmSUTWI3U8Dakq45kSDH1XlQLnSrb/P2aZ sFAT9Qj9Gx/OgxX8uhPtNANcGx3Vvk5+VFmHSB4HVnO+Nuu2deQjV3WYhCBTwpnepSQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b="BUG+KYe/"; 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 AB0C6606B8BD; Sat, 7 Nov 2026 14:58:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=BUG+KYe/ Received: by smtp.kernel.org (Postfix) with ESMTPSA id 576CC1F008A5; Sat, 7 Nov 2026 14:58:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794063516; bh=d6zjBtVg5oO1t5dBT9zeHbAkGkx8g5x/6dUn6S/Uk8A=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=BUG+KYe/Fk9HQbd1ukbGw2SNmjOnWzsEjO9gxT6MRoX2biJamVkaOPBV+c6S5aA8f G+jY5wKTUipca28CIo/i2zDY0Ndsrf6Mh0x52C/OQvMXLrIAHaTyFfKfHeZMjcbWuv uIAROUPtu8Ee8TJJRKyX8x9jdFipKGKSt3deGYQo= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Adrian Ambrozewicz , Kent Gibson , Bartosz Golaszewski , Sasha Levin Subject: [PATCH 6.18 641/869] gpiolib: cdev: dont set GPIOD_FLAG_IS_OUT Date: Sat, 7 Nov 2026 08:55:23 -0500 Message-ID: <20261107134914.653021967@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261107134852.069646174@linuxfoundation.org> References: <20261107134852.069646174@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore 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 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ 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 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 d67d361cc4562..1afda8ea5769b 100644 --- a/drivers/gpio/gpiolib-cdev.c +++ b/drivers/gpio/gpiolib-cdev.c @@ -1253,11 +1253,6 @@ static void gpio_v2_line_config_flags_to_desc_flags(u64 lflags, assign_bit(GPIOD_FLAG_ACTIVE_LOW, &flags, lflags & GPIO_V2_LINE_FLAG_ACTIVE_LOW); - if (lflags & GPIO_V2_LINE_FLAG_OUTPUT) - set_bit(GPIOD_FLAG_IS_OUT, &flags); - else if (lflags & GPIO_V2_LINE_FLAG_INPUT) - clear_bit(GPIOD_FLAG_IS_OUT, &flags); - assign_bit(GPIOD_FLAG_EDGE_RISING, &flags, lflags & GPIO_V2_LINE_FLAG_EDGE_RISING); assign_bit(GPIOD_FLAG_EDGE_FALLING, &flags, -- 2.53.0