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b=y/yFatKQEjRUiKUCfMpJ32w6fKMxdCTivrLppKwZx7X2LJcKTWp+ZVYaJbCZcVTouVeaDC74rCKXDF/hKVcoHUwDSNCqZX0vsWqp18sbLRWYT8NVcW0W6QMOw7NSgMyD/417BVEpaY2O/aqSVx80ZjAz5ubQ/j2tobB+SB5ppcI= Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=kunbus.com; Received: from VI1P193MB0413.EURP193.PROD.OUTLOOK.COM (2603:10a6:803:4e::14) by GV1P193MB2245.EURP193.PROD.OUTLOOK.COM (2603:10a6:150:2c::11) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7135.25; Wed, 3 Jan 2024 06:19:10 +0000 Received: from VI1P193MB0413.EURP193.PROD.OUTLOOK.COM ([fe80::67b0:68bf:2582:19cb]) by VI1P193MB0413.EURP193.PROD.OUTLOOK.COM ([fe80::67b0:68bf:2582:19cb%6]) with mapi id 15.20.7159.013; Wed, 3 Jan 2024 06:19:10 +0000 From: Lino Sanfilippo To: gregkh@linuxfoundation.org, jirislaby@kernel.org, ilpo.jarvinen@linux.intel.com Cc: u.kleine-koenig@pengutronix.de, shawnguo@kernel.org, s.hauer@pengutronix.de, mcoquelin.stm32@gmail.com, alexandre.torgue@foss.st.com, cniedermaier@dh-electronics.com, hugo@hugovil.com, m.brock@vanmierlo.com, linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org, LinoSanfilippo@gmx.de, lukas@wunner.de, p.rosenberger@kunbus.com, Lino Sanfilippo , stable@vger.kernel.org Subject: [PATCH v7 1/7] serial: Do not hold the port lock when setting rx-during-tx GPIO Date: Wed, 3 Jan 2024 07:18:12 +0100 Message-ID: <20240103061818.564-2-l.sanfilippo@kunbus.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240103061818.564-1-l.sanfilippo@kunbus.com> References: <20240103061818.564-1-l.sanfilippo@kunbus.com> X-ClientProxiedBy: FR0P281CA0267.DEUP281.PROD.OUTLOOK.COM (2603:10a6:d10:b5::13) To VI1P193MB0413.EURP193.PROD.OUTLOOK.COM (2603:10a6:803:4e::14) Precedence: bulk X-Mailing-List: linux-serial@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: VI1P193MB0413:EE_|GV1P193MB2245:EE_ X-MS-Office365-Filtering-Correlation-Id: 01f1d246-a59f-4310-bb13-08dc0c23e5c1 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; 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Since this function is called with the port lock held, this can be a problem in case that setting the GPIO line can sleep (e.g. if a GPIO expander is used which is connected via SPI or I2C). Avoid this issue by moving the GPIO setting outside of the port lock into the serial core and thus making it a generic feature. Also with commit c54d48543689 ("serial: stm32: Add support for rs485 RX_DURING_TX output GPIO") the SER_RS485_RX_DURING_TX flag is only set if a rx-during-tx GPIO is _not_ available, which is wrong. Fix this, too. Furthermore reset old GPIO settings in case that changing the RS485 configuration failed. Fixes: c54d48543689 ("serial: stm32: Add support for rs485 RX_DURING_TX output GPIO") Fixes: ca530cfa968c ("serial: imx: Add support for RS485 RX_DURING_TX output GPIO") Cc: Shawn Guo Cc: Sascha Hauer Cc: stable@vger.kernel.org Signed-off-by: Lino Sanfilippo --- drivers/tty/serial/imx.c | 4 ---- drivers/tty/serial/serial_core.c | 26 ++++++++++++++++++++++++-- drivers/tty/serial/stm32-usart.c | 8 ++------ 3 files changed, 26 insertions(+), 12 deletions(-) diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index 708b9852a575..9cffeb23112b 100644 --- a/drivers/tty/serial/imx.c +++ b/drivers/tty/serial/imx.c @@ -1943,10 +1943,6 @@ static int imx_uart_rs485_config(struct uart_port *port, struct ktermios *termio rs485conf->flags & SER_RS485_RX_DURING_TX) imx_uart_start_rx(port); - if (port->rs485_rx_during_tx_gpio) - gpiod_set_value_cansleep(port->rs485_rx_during_tx_gpio, - !!(rs485conf->flags & SER_RS485_RX_DURING_TX)); - return 0; } diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index f1348a509552..d155131f221d 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -1402,6 +1402,16 @@ static void uart_set_rs485_termination(struct uart_port *port, !!(rs485->flags & SER_RS485_TERMINATE_BUS)); } +static void uart_set_rs485_rx_during_tx(struct uart_port *port, + const struct serial_rs485 *rs485) +{ + if (!(rs485->flags & SER_RS485_ENABLED)) + return; + + gpiod_set_value_cansleep(port->rs485_rx_during_tx_gpio, + !!(rs485->flags & SER_RS485_RX_DURING_TX)); +} + static int uart_rs485_config(struct uart_port *port) { struct serial_rs485 *rs485 = &port->rs485; @@ -1413,12 +1423,17 @@ static int uart_rs485_config(struct uart_port *port) uart_sanitize_serial_rs485(port, rs485); uart_set_rs485_termination(port, rs485); + uart_set_rs485_rx_during_tx(port, rs485); uart_port_lock_irqsave(port, &flags); ret = port->rs485_config(port, NULL, rs485); uart_port_unlock_irqrestore(port, flags); - if (ret) + if (ret) { memset(rs485, 0, sizeof(*rs485)); + /* unset GPIOs */ + gpiod_set_value_cansleep(port->rs485_term_gpio, 0); + gpiod_set_value_cansleep(port->rs485_rx_during_tx_gpio, 0); + } return ret; } @@ -1457,6 +1472,7 @@ static int uart_set_rs485_config(struct tty_struct *tty, struct uart_port *port, return ret; uart_sanitize_serial_rs485(port, &rs485); uart_set_rs485_termination(port, &rs485); + uart_set_rs485_rx_during_tx(port, &rs485); uart_port_lock_irqsave(port, &flags); ret = port->rs485_config(port, &tty->termios, &rs485); @@ -1468,8 +1484,14 @@ static int uart_set_rs485_config(struct tty_struct *tty, struct uart_port *port, port->ops->set_mctrl(port, port->mctrl); } uart_port_unlock_irqrestore(port, flags); - if (ret) + if (ret) { + /* restore old GPIO settings */ + gpiod_set_value_cansleep(port->rs485_term_gpio, + !!(port->rs485.flags & SER_RS485_TERMINATE_BUS)); + gpiod_set_value_cansleep(port->rs485_rx_during_tx_gpio, + !!(port->rs485.flags & SER_RS485_RX_DURING_TX)); return ret; + } if (copy_to_user(rs485_user, &port->rs485, sizeof(port->rs485))) return -EFAULT; diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c index 3048620315d6..fc7fd40bca98 100644 --- a/drivers/tty/serial/stm32-usart.c +++ b/drivers/tty/serial/stm32-usart.c @@ -226,12 +226,6 @@ static int stm32_usart_config_rs485(struct uart_port *port, struct ktermios *ter stm32_usart_clr_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit)); - if (port->rs485_rx_during_tx_gpio) - gpiod_set_value_cansleep(port->rs485_rx_during_tx_gpio, - !!(rs485conf->flags & SER_RS485_RX_DURING_TX)); - else - rs485conf->flags |= SER_RS485_RX_DURING_TX; - if (rs485conf->flags & SER_RS485_ENABLED) { cr1 = readl_relaxed(port->membase + ofs->cr1); cr3 = readl_relaxed(port->membase + ofs->cr3); @@ -256,6 +250,8 @@ static int stm32_usart_config_rs485(struct uart_port *port, struct ktermios *ter writel_relaxed(cr3, port->membase + ofs->cr3); writel_relaxed(cr1, port->membase + ofs->cr1); + + rs485conf->flags |= SER_RS485_RX_DURING_TX; } else { stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_DEM | USART_CR3_DEP);