From patchwork Fri Feb 14 08:38:01 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Alexis_Lothor=C3=A9_=28eBPF_Foundation=29?= X-Patchwork-Id: 865280 Received: from relay2-d.mail.gandi.net (relay2-d.mail.gandi.net [217.70.183.194]) (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 CACFB1F8908; Fri, 14 Feb 2025 08:38:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.70.183.194 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739522295; cv=none; b=X6Bn5Ho+7tH7HICXlhMTfb4ejBjNbKIYwOWqC1IJtZUSBJftrXgtRKgR09G94MquJ/ceLUCdpGUjZShUxF+h8itISZFzSQhSKcAJYrqKpyuWMLG7zkOn0Kc0FH+B4Ok5/9au9FaDMhkKU1eW38YDMBBiLlcivbFdZu39raqp2FM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739522295; c=relaxed/simple; bh=Uon8qEGH5SAL+tYfQO8BOWt1CW8CSbYRLo16Ya3AJP4=; 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d=bootlin.com; s=gm1; t=1739522290; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=tBXtQKspl/tQc262TteMj1K5AZZrIiuUgh3p3e1Bj8A=; b=Ex59S/KNwROOk1PwwvtxM9GKHtgky3sFkhbU7jy5wYAL/i+5/1UYcClvUg5n9f9iDuGiQ/ 6Rh14vi3u+X+/Gn8IqhkT8iWWyYJh4Y5owvjM8tyuDSsC2Ls4ZERdMYqRH0LzV1+XnTbN6 3ZXHJSfJMP5e9cMdP8N+DqZipPsZ+bAwUGVnxEXBZInCsCrqfYpkhfVJZs+rI3pDN76SPA WGG06i9NneGrFVq4OLt248K7gfn62GNdKj6VMzjhnlXigWFjoJdSYK4gphYPefK61xWORM uBPDPC6n6nws7ALKsHvfvwCGn4PPZVy+IEOGMJc2MsISUq6PvvDaTsbNmNPieQ== From: =?utf-8?q?Alexis_Lothor=C3=A9?= Date: Fri, 14 Feb 2025 09:38:01 +0100 Subject: [PATCH v2] serial: mctrl_gpio: add parameter to skip sync Precedence: bulk X-Mailing-List: linux-serial@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20250214-atomic_sleep_mctrl_serial_gpio-v2-1-1e60c732fd90@bootlin.com> X-B4-Tracking: v=1; b=H4sIAOgAr2cC/42NQQqDMBAAv1L23BSTNhJ66j+KhBhXXYiuJEFax L83+oIeZw4zGySMhAmelw0irpSI5wLqegE/unlAQV1hUJXSlZJ34TJP5G0KiIudfI7BHgkX7LA QC2N0X/fYaqNbKJElYk+fc/BuCo+UMsfv+VvlYf9Or1JIoSqJWDv5MK57tcw50HzzPEGz7/sPk DTZtM4AAAA= X-Change-ID: 20250213-atomic_sleep_mctrl_serial_gpio-885f6feb585b To: Greg Kroah-Hartman , Jiri Slaby , Richard Genoud , Nicolas Ferre , Alexandre Belloni , Claudiu Beznea , Shawn Guo , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , Maxime Coquelin , Alexandre Torgue , Jonathan Corbet Cc: Thomas Petazzoni , linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org, linux-arm-kernel@lists.infradead.org, imx@lists.linux.dev, linux-stm32@st-md-mailman.stormreply.com, linux-doc@vger.kernel.org, =?utf-8?q?Alexis_Lothor=C3=A9?= X-Mailer: b4 0.14.2 X-GND-State: clean X-GND-Score: -100 X-GND-Cause: gggruggvucftvghtrhhoucdtuddrgeefvddrtddtgdegledulecutefuodetggdotefrodftvfcurfhrohhfihhlvgemucfitefpfffkpdcuggftfghnshhusghstghrihgsvgenuceurghilhhouhhtmecufedtudenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujfgurhephfffufggtgfgkffvvefosehtkeertdertdejnecuhfhrohhmpeetlhgvgihishcunfhothhhohhrrocuoegrlhgvgihishdrlhhothhhohhrvgessghoohhtlhhinhdrtghomheqnecuggftrfgrthhtvghrnhepudekveeftdeifedvfefgvdfgjeduieevudeltdeulefhhefgiedvhfethffgffegnecuffhomhgrihhnpehkvghrnhgvlhdrohhrghdpsghoohhtlhhinhdrtghomhenucfkphepledtrdekledrudeifedruddvjeenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepihhnvghtpeeltddrkeelrdduieefrdduvdejpdhhvghloheplgdujedvrddujedrtddrudgnpdhmrghilhhfrhhomheprghlvgigihhsrdhlohhthhhorhgvsegsohhothhlihhnrdgtohhmpdhnsggprhgtphhtthhopedvuddprhgtphhtthhopehlihhnuhigqdgrrhhmqdhkvghrnhgvlheslhhishhtshdrihhnfhhrrgguvggrugdrohhrghdprhgtphhtthhopegtlhgruhguihhurdgsvgiinhgvrgesthhugihonhdruggvvhdprhgtphhtthhopehshhgrfihnghhuoheskhgvrhhnvghlrdhorhhgpdhrtghpthhtoheptghorhgsv ghtsehlfihnrdhnvghtpdhrtghpthhtohepihhmgieslhhishhtshdrlhhinhhugidruggvvhdprhgtphhtthhopehjihhrihhslhgrsgihsehkvghrnhgvlhdrohhrghdprhgtphhtthhopehfvghsthgvvhgrmhesghhmrghilhdrtghomhdprhgtphhtthhopehnihgtohhlrghsrdhfvghrrhgvsehmihgtrhhotghhihhprdgtohhm X-GND-Sasl: alexis.lothore@bootlin.com The following splat has been observed on a SAMA5D27 platform using atmel_serial: BUG: sleeping function called from invalid context at kernel/irq/manage.c:738 in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 27, name: kworker/u5:0 preempt_count: 1, expected: 0 INFO: lockdep is turned off. irq event stamp: 0 hardirqs last enabled at (0): [<00000000>] 0x0 hardirqs last disabled at (0): [] copy_process+0x1c4c/0x7bec softirqs last enabled at (0): [] copy_process+0x1ca0/0x7bec softirqs last disabled at (0): [<00000000>] 0x0 CPU: 0 UID: 0 PID: 27 Comm: kworker/u5:0 Not tainted 6.13.0-rc7+ #74 Hardware name: Atmel SAMA5 Workqueue: hci0 hci_power_on [bluetooth] Call trace: unwind_backtrace from show_stack+0x18/0x1c show_stack from dump_stack_lvl+0x44/0x70 dump_stack_lvl from __might_resched+0x38c/0x598 __might_resched from disable_irq+0x1c/0x48 disable_irq from mctrl_gpio_disable_ms+0x74/0xc0 mctrl_gpio_disable_ms from atmel_disable_ms.part.0+0x80/0x1f4 atmel_disable_ms.part.0 from atmel_set_termios+0x764/0x11e8 atmel_set_termios from uart_change_line_settings+0x15c/0x994 uart_change_line_settings from uart_set_termios+0x2b0/0x668 uart_set_termios from tty_set_termios+0x600/0x8ec tty_set_termios from ttyport_set_flow_control+0x188/0x1e0 ttyport_set_flow_control from wilc_setup+0xd0/0x524 [hci_wilc] wilc_setup [hci_wilc] from hci_dev_open_sync+0x330/0x203c [bluetooth] hci_dev_open_sync [bluetooth] from hci_dev_do_open+0x40/0xb0 [bluetooth] hci_dev_do_open [bluetooth] from hci_power_on+0x12c/0x664 [bluetooth] hci_power_on [bluetooth] from process_one_work+0x998/0x1a38 process_one_work from worker_thread+0x6e0/0xfb4 worker_thread from kthread+0x3d4/0x484 kthread from ret_from_fork+0x14/0x28 This warning is emitted when trying to toggle, at the highest level, some flow control (with serdev_device_set_flow_control) in a device driver. At the lowest level, the atmel_serial driver is using serial_mctrl_gpio lib to enable/disable the corresponding IRQs accordingly. The warning emitted by CONFIG_DEBUG_ATOMIC_SLEEP is due to disable_irq (called in mctrl_gpio_disable_ms) being possibly called in some atomic context (some tty drivers perform modem lines configuration in regions protected by port lock). Split mctrl_gpio_disable_ms into two differents APIs, a non-blocking one and a blocking one. Replace mctrl_gpio_disable_ms calls with the relevant version depending on whether the call is protected by some port lock. Suggested-by: Jiri Slaby Signed-off-by: Alexis Lothoré --- Changes in v2: - create dedicated APIs instead of using custom flag - Link to v1: https://lore.kernel.org/r/20250213-atomic_sleep_mctrl_serial_gpio-v1-1-201ee6a148ad@bootlin.com --- Documentation/driver-api/serial/driver.rst | 2 +- drivers/tty/serial/8250/8250_port.c | 2 +- drivers/tty/serial/atmel_serial.c | 2 +- drivers/tty/serial/imx.c | 2 +- drivers/tty/serial/serial_mctrl_gpio.c | 34 ++++++++++++++++++++++++------ drivers/tty/serial/serial_mctrl_gpio.h | 17 ++++++++++++--- drivers/tty/serial/sh-sci.c | 2 +- drivers/tty/serial/stm32-usart.c | 2 +- 8 files changed, 47 insertions(+), 16 deletions(-) --- base-commit: 2014c95afecee3e76ca4a56956a936e23283f05b change-id: 20250213-atomic_sleep_mctrl_serial_gpio-885f6feb585b Best regards, diff --git a/Documentation/driver-api/serial/driver.rst b/Documentation/driver-api/serial/driver.rst index 84b43061c11be2d6b4e3cd29fb8e6ecbdebe646d..60434f2b0286373d64b7aa8ae309454d7bd8859e 100644 --- a/Documentation/driver-api/serial/driver.rst +++ b/Documentation/driver-api/serial/driver.rst @@ -103,4 +103,4 @@ Some helpers are provided in order to set/get modem control lines via GPIO. .. kernel-doc:: drivers/tty/serial/serial_mctrl_gpio.c :identifiers: mctrl_gpio_init mctrl_gpio_free mctrl_gpio_to_gpiod mctrl_gpio_set mctrl_gpio_get mctrl_gpio_enable_ms - mctrl_gpio_disable_ms + mctrl_gpio_disable_ms_sync mctrl_gpio_disable_ms_no_sync diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c index d7976a21cca9ce50557ca5f13bb01448ced0728b..218a1d98f1ed3e2697624444be33243050df3a85 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -1680,7 +1680,7 @@ static void serial8250_disable_ms(struct uart_port *port) if (up->bugs & UART_BUG_NOMSR) return; - mctrl_gpio_disable_ms(up->gpios); + mctrl_gpio_disable_ms_no_sync(up->gpios); up->ier &= ~UART_IER_MSI; serial_port_out(port, UART_IER, up->ier); diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c index f44f9d20a97440c9aea41e9ebe34c34d4dfa0a1c..8918fbd4bddd5dfe7705a75d4132dda59fe9e5e6 100644 --- a/drivers/tty/serial/atmel_serial.c +++ b/drivers/tty/serial/atmel_serial.c @@ -700,7 +700,7 @@ static void atmel_disable_ms(struct uart_port *port) atmel_port->ms_irq_enabled = false; - mctrl_gpio_disable_ms(atmel_port->gpios); + mctrl_gpio_disable_ms_no_sync(atmel_port->gpios); if (!mctrl_gpio_to_gpiod(atmel_port->gpios, UART_GPIO_CTS)) idr |= ATMEL_US_CTSIC; diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index 9c59ec128bb4fc0ff54cb9a1a66eabbc9e391a9a..cfeb3f8cf45eaeea8afaa767a4ad849bb8d19f69 100644 --- a/drivers/tty/serial/imx.c +++ b/drivers/tty/serial/imx.c @@ -1608,7 +1608,7 @@ static void imx_uart_shutdown(struct uart_port *port) imx_uart_dma_exit(sport); } - mctrl_gpio_disable_ms(sport->gpios); + mctrl_gpio_disable_ms_sync(sport->gpios); uart_port_lock_irqsave(&sport->port, &flags); ucr2 = imx_uart_readl(sport, UCR2); diff --git a/drivers/tty/serial/serial_mctrl_gpio.c b/drivers/tty/serial/serial_mctrl_gpio.c index 8855688a5b6c09f073349bd144586f54331d891f..ca55bcc0b61119d0b76e6943e0f223a4a9e25c02 100644 --- a/drivers/tty/serial/serial_mctrl_gpio.c +++ b/drivers/tty/serial/serial_mctrl_gpio.c @@ -322,11 +322,7 @@ void mctrl_gpio_enable_ms(struct mctrl_gpios *gpios) } EXPORT_SYMBOL_GPL(mctrl_gpio_enable_ms); -/** - * mctrl_gpio_disable_ms - disable irqs and handling of changes to the ms lines - * @gpios: gpios to disable - */ -void mctrl_gpio_disable_ms(struct mctrl_gpios *gpios) +static void mctrl_gpio_disable_ms(struct mctrl_gpios *gpios, bool sync) { enum mctrl_gpio_idx i; @@ -342,10 +338,34 @@ void mctrl_gpio_disable_ms(struct mctrl_gpios *gpios) if (!gpios->irq[i]) continue; - disable_irq(gpios->irq[i]); + if (sync) + disable_irq(gpios->irq[i]); + else + disable_irq_nosync(gpios->irq[i]); } } -EXPORT_SYMBOL_GPL(mctrl_gpio_disable_ms); + +/** + * mctrl_gpio_disable_ms_sync - disable irqs and handling of changes to the ms + * lines, and wait for any pending IRQ to be processed + * @gpios: gpios to disable + */ +void mctrl_gpio_disable_ms_sync(struct mctrl_gpios *gpios) +{ + mctrl_gpio_disable_ms(gpios, true); +} +EXPORT_SYMBOL_GPL(mctrl_gpio_disable_ms_sync); + +/** + * mctrl_gpio_disable_ms_no_sync - disable irqs and handling of changes to the + * ms lines, and return immediately + * @gpios: gpios to disable + */ +void mctrl_gpio_disable_ms_no_sync(struct mctrl_gpios *gpios) +{ + mctrl_gpio_disable_ms(gpios, false); +} +EXPORT_SYMBOL_GPL(mctrl_gpio_disable_ms_no_sync); void mctrl_gpio_enable_irq_wake(struct mctrl_gpios *gpios) { diff --git a/drivers/tty/serial/serial_mctrl_gpio.h b/drivers/tty/serial/serial_mctrl_gpio.h index fc76910fb105a3d560e824baa43e9515576e895a..79e97838ebe5672a1b00ef848dcda1e8c1b9568e 100644 --- a/drivers/tty/serial/serial_mctrl_gpio.h +++ b/drivers/tty/serial/serial_mctrl_gpio.h @@ -87,9 +87,16 @@ void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios); void mctrl_gpio_enable_ms(struct mctrl_gpios *gpios); /* - * Disable gpio interrupts to report status line changes. + * Disable gpio interrupts to report status line changes, and block until + * any corresponding IRQ is processed */ -void mctrl_gpio_disable_ms(struct mctrl_gpios *gpios); +void mctrl_gpio_disable_ms_sync(struct mctrl_gpios *gpios); + +/* + * Disable gpio interrupts to report status line changes, and return + * immediately + */ +void mctrl_gpio_disable_ms_no_sync(struct mctrl_gpios *gpios); /* * Enable gpio wakeup interrupts to enable wake up source. @@ -148,7 +155,11 @@ static inline void mctrl_gpio_enable_ms(struct mctrl_gpios *gpios) { } -static inline void mctrl_gpio_disable_ms(struct mctrl_gpios *gpios) +static inline void mctrl_gpio_disable_ms_sync(struct mctrl_gpios *gpios) +{ +} + +static inline void mctrl_gpio_disable_ms_no_sync(struct mctrl_gpios *gpios) { } diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index b1ea48f38248eb42d98353daa289bbe67191d201..41f987632bce82c9d041d9ab1f5162d2af1a78e4 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -2298,7 +2298,7 @@ static void sci_shutdown(struct uart_port *port) dev_dbg(port->dev, "%s(%d)\n", __func__, port->line); s->autorts = false; - mctrl_gpio_disable_ms(to_sci_port(port)->gpios); + mctrl_gpio_disable_ms_sync(to_sci_port(port)->gpios); uart_port_lock_irqsave(port, &flags); sci_stop_rx(port); diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c index 1ec5d8c3aef8ddbca615a149c2fe81c90c83a22b..4c97965ec43b30113a255661e6a64a6b476d7a9c 100644 --- a/drivers/tty/serial/stm32-usart.c +++ b/drivers/tty/serial/stm32-usart.c @@ -944,7 +944,7 @@ static void stm32_usart_enable_ms(struct uart_port *port) static void stm32_usart_disable_ms(struct uart_port *port) { - mctrl_gpio_disable_ms(to_stm32_port(port)->gpios); + mctrl_gpio_disable_ms_sync(to_stm32_port(port)->gpios); } /* Transmit stop */