From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 81D2B46D089; Tue, 21 Jul 2026 18:20:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784658047; cv=none; b=Ed1PFMDXlDZMMASUiyQ1FqK62GxDix12lN6J/2AgUFJr8mMp+IvrORL4E1/hSowvi3OrvSS5FwzN54P5mzDhujYP2eHamTZemMqEgBsz7JDYBdLTUBcN9CO33KTXCV1sC3vI8mji+RKL37pQMkt6/QoI6U6atWRmVGR7TaDHPcQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784658047; c=relaxed/simple; bh=e3U8NWnOP+UMjrqLEoAD/MLVHUWOireGKwmxJ5qzq3I=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=VfPpL55BX8okn456x7Q/WFhdAHEkNtXHNw6CgpS5up9WsW1cyQ9dUzVHhos01PmuxTjdGeziCcwh51SyfdNFE9Row9c0URLt3iJ3H6FvkWnJAn2Izn9/FbQgGL04FXUXFcHLmDI3liC+9/G0GPKQTNbjjdYWTLG4YoJkZ+vo3ok= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=OcmqcRcH; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="OcmqcRcH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E89081F000E9; Tue, 21 Jul 2026 18:20:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784658045; bh=zlpSwhcGjm4YdCOr+zxqjXhCHsTNIBJDVtL2FVkBnj8=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=OcmqcRcHlWfPlcbxVxDaYRrZILwzyC3LCBpFW3sfKuVAX16Ddy/tiC1GrUvuUHdlo 8AM8r9am3Buid2/sqaYpv+KXz5cKiCZ4eRbUD7HFksM1YgCLG9E4XK6STMzNdCNwsV TkUjNg82UG8DoLK4irZja+GK9NSK3krUBeB7EGME= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Viacheslav Bocharov , Linus Walleij , Bartosz Golaszewski , Sasha Levin Subject: [PATCH 6.18 0995/1611] pinctrl: meson: restore non-sleeping GPIO access Date: Tue, 21 Jul 2026 17:18:31 +0200 Message-ID: <20260721152537.771929029@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152514.750365251@linuxfoundation.org> References: <20260721152514.750365251@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Viacheslav Bocharov [ Upstream commit 9777530157e7b82fd994327ff878c4245dadc931 ] Commit 28f240683871 ("pinctrl: meson: mark the GPIO controller as sleeping") set gpio_chip.can_sleep = true to work around gpio-shared-proxy holding a spinlock across a sleeping pinctrl config path. That locking bug is now fixed in the shared-proxy itself ("gpio: shared-proxy: always serialize with a sleeping mutex"), so the controller-wide workaround is no longer needed; the meson GPIO controller does not sleep. meson_gpio_get/set/direction_* access MMIO through regmap. The regmap_mmio bus uses fast I/O (spinlock) locking, so these value callbacks do not contain sleeping operations. Since gpio_chip.can_sleep describes the get/set value path, restore can_sleep = false. Marking the controller sleeping also broke atomic value consumers such as w1-gpio (1-Wire bitbang): w1_io.c runs its read time slot under local_irq_save() and uses the non-cansleep gpiod_set_value() / gpiod_get_value(), which with can_sleep=true trigger WARN_ON(can_sleep) in gpiolib on every transferred bit (from w1_gpio_write_bit() / w1_gpio_read_bit() via w1_reset_bus() and w1_search()). The printk and stack dump inside the IRQs-off, microsecond-scale time slot destroy the bit timing, so reset/presence detection and ROM search fail: the bus master registers but w1_master_slave_count stays at 0 and no devices are found. Verified on an Amlogic A113X board (DS18B20 on GPIOA_14): with can_sleep restored to false the warnings are gone and the sensor is detected and read again. This must not be applied or backported without the shared-proxy locking fix above; otherwise the original Khadas VIM3 splat returns on boards that genuinely share a meson GPIO. Fixes: 28f240683871 ("pinctrl: meson: mark the GPIO controller as sleeping") Link: https://lore.kernel.org/all/20260105150509.56537-1-bartosz.golaszewski@oss.qualcomm.com/ Signed-off-by: Viacheslav Bocharov Acked-by: Linus Walleij Link: https://patch.msgid.link/20260625115718.1678991-3-v@baodeep.com Signed-off-by: Bartosz Golaszewski Signed-off-by: Sasha Levin --- drivers/pinctrl/meson/pinctrl-meson.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/pinctrl/meson/pinctrl-meson.c b/drivers/pinctrl/meson/pinctrl-meson.c index 4507dc8b5563c0..18295b15ecd9dd 100644 --- a/drivers/pinctrl/meson/pinctrl-meson.c +++ b/drivers/pinctrl/meson/pinctrl-meson.c @@ -619,7 +619,7 @@ static int meson_gpiolib_register(struct meson_pinctrl *pc) pc->chip.set = meson_gpio_set; pc->chip.base = -1; pc->chip.ngpio = pc->data->num_pins; - pc->chip.can_sleep = true; + pc->chip.can_sleep = false; ret = gpiochip_add_data(&pc->chip, pc); if (ret) { -- 2.53.0