From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx.adeep.su (mx.adeep.su [185.250.0.168]) (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 CEECC3F0765; Tue, 30 Jun 2026 10:16:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.250.0.168 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782814609; cv=none; b=kw7a33+9DOPcYvmSU8P6pOiPbZPO7OHdNjGALwlwrAd7hm2kxEpHdMico2xWY6wg6oVbB+OGjcf70n1vEm9nG1sYQ18scRCBG9jJj3i/ZUXwF9fN1dW2EL/ArVAYwsJRQjPGyw4R/dOTLxTsvifTouAyQ/erNI4WnIKJ6wUnP8I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782814609; c=relaxed/simple; bh=25aU2hceVzQziDHfDp/HHyY1r1n7srn2v3XJTVOkf1k=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=OIRHgoyZSmWcxsV1u9KYxCxHjtO8TXOn4hG479KI/b8T3obOFqvBIMvMyfo8ve2/qNG+SPf/UdEMmP8cDdtlXzMASeCgyh4yjna+NimEb+7WbHDeme7UT93Wk6TRSj7YYnqDbO3pty+4FeiGrLPYRmcS+Dp9ljTapjyZNT1zZf0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=baodeep.com; spf=pass smtp.mailfrom=baodeep.com; dkim=fail (2048-bit key) header.d=baodeep.com header.i=@baodeep.com header.b=CPeInz/P reason="signature verification failed"; arc=none smtp.client-ip=185.250.0.168 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=baodeep.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=baodeep.com Authentication-Results: smtp.subspace.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=baodeep.com header.i=@baodeep.com header.b="CPeInz/P" Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 0A8C21CD232; Tue, 30 Jun 2026 13:16:34 +0300 (MSK) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=baodeep.com; s=dkim; t=1782814602; h=from:subject:date:message-id:to:cc:mime-version: content-transfer-encoding:in-reply-to:references; bh=wubwNYnRxbbJb5iwummV8vvrrP0RpUNviFPSyRr144w=; b=CPeInz/PD9TfYK5P2xBKbWzAuQ9Pn0cbTUo9LrCjhuQh3OZBirifZDmplUpkVHG7460bLY jpz9ZcannzFXFYkvrvVKT4znbrFaWqptJM3ELVrI4mgRTSZYdcp0jmxu4RZFmDls3qMyZB CYggGjJo8BGctjyd3eNkVwOu+Qxqsj7LjQ31CvHHEjL3RnXZoULbvpFml4LWY8CIjyQQXZ Z/KdYPV8HPNUW95gFahDnR8ElRhHO6wNp8D1lWZE0QQIBwtk0HkGfs28PFdZi3znxnOdjz 6gzT6LJ1j3zhxZ+6iz2s7zXZDerH324yotiuIIj5OKpXFVzJdaZcXEMpl5TTug== From: Viacheslav Bocharov To: Linus Walleij , Bartosz Golaszewski Cc: Neil Armstrong , Kevin Hilman , Jerome Brunet , Martin Blumenstingl , Marek Szyprowski , Robin Murphy , Diederik de Haas , linux-gpio@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-amlogic@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 2/2] pinctrl: meson: restore non-sleeping GPIO access Date: Tue, 30 Jun 2026 13:15:45 +0300 Message-ID: <20260630101545.800625-3-v@baodeep.com> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260630101545.800625-1-v@baodeep.com> References: <20260630101545.800625-1-v@baodeep.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Last-TLS-Session-Version: TLSv1.3 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 --- 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 4507dc8b5563..18295b15ecd9 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) { -- 2.54.0