From 24ec03cc55126b7b3adf102f4b3d9f716532b329 Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Thu, 27 Nov 2025 17:36:50 +0100 Subject: serial: core: Restore sysfs fwnode information The change that restores sysfs fwnode information does it only for OF cases. Update the fix to cover all possible types of fwnodes. Fixes: d36f0e9a0002 ("serial: core: restore of_node information in sysfs") Cc: stable Signed-off-by: Andy Shevchenko Link: https://patch.msgid.link/20251127163650.2942075-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/serial_base_bus.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) (limited to 'drivers/tty') diff --git a/drivers/tty/serial/serial_base_bus.c b/drivers/tty/serial/serial_base_bus.c index 22749ab0428a..8e891984cdc0 100644 --- a/drivers/tty/serial/serial_base_bus.c +++ b/drivers/tty/serial/serial_base_bus.c @@ -13,7 +13,7 @@ #include #include #include -#include +#include #include #include #include @@ -60,6 +60,7 @@ void serial_base_driver_unregister(struct device_driver *driver) driver_unregister(driver); } +/* On failure the caller must put device @dev with put_device() */ static int serial_base_device_init(struct uart_port *port, struct device *dev, struct device *parent_dev, @@ -73,7 +74,8 @@ static int serial_base_device_init(struct uart_port *port, dev->parent = parent_dev; dev->bus = &serial_base_bus_type; dev->release = release; - device_set_of_node_from_dev(dev, parent_dev); + + device_set_node(dev, fwnode_handle_get(dev_fwnode(parent_dev))); if (!serial_base_initialized) { dev_dbg(port->dev, "uart_add_one_port() called before arch_initcall()?\n"); @@ -94,7 +96,7 @@ static void serial_base_ctrl_release(struct device *dev) { struct serial_ctrl_device *ctrl_dev = to_serial_base_ctrl_device(dev); - of_node_put(dev->of_node); + fwnode_handle_put(dev_fwnode(dev)); kfree(ctrl_dev); } @@ -142,7 +144,7 @@ static void serial_base_port_release(struct device *dev) { struct serial_port_device *port_dev = to_serial_base_port_device(dev); - of_node_put(dev->of_node); + fwnode_handle_put(dev_fwnode(dev)); kfree(port_dev); } -- cgit v1.2.3 From 5edb7338d6117bb0ce17ead7973c67390da42258 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Sat, 29 Nov 2025 17:51:23 +0300 Subject: serial: 8250: longson: Fix NULL vs IS_ERR() bug in probe The devm_platform_get_and_ioremap_resource() function never returns NULL, it returns error pointers. Fix the error checking to match. Fixes: 25e95d763176 ("serial: 8250: Add Loongson uart driver support") Signed-off-by: Dan Carpenter Link: https://patch.msgid.link/aSsIa3KdAlXh5uQC@stanley.mountain Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_loongson.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/tty') diff --git a/drivers/tty/serial/8250/8250_loongson.c b/drivers/tty/serial/8250/8250_loongson.c index 53153a116c01..47df3c4c9d21 100644 --- a/drivers/tty/serial/8250/8250_loongson.c +++ b/drivers/tty/serial/8250/8250_loongson.c @@ -128,8 +128,8 @@ static int loongson_uart_probe(struct platform_device *pdev) port->private_data = priv; port->membase = devm_platform_get_and_ioremap_resource(pdev, 0, &priv->res); - if (!port->membase) - return -ENOMEM; + if (IS_ERR(port->membase)) + return PTR_ERR(port->membase); port->mapbase = priv->res->start; port->mapsize = resource_size(priv->res); -- cgit v1.2.3 From f54151148b969fb4b62bec8093d255306d20df30 Mon Sep 17 00:00:00 2001 From: Alexander Stein Date: Fri, 19 Dec 2025 16:28:12 +0100 Subject: serial: core: Fix serial device initialization During restoring sysfs fwnode information the information of_node_reused was dropped. This was previously set by device_set_of_node_from_dev(). Add it back manually Fixes: 24ec03cc5512 ("serial: core: Restore sysfs fwnode information") Cc: stable Suggested-by: Cosmin Tanislav Signed-off-by: Alexander Stein Tested-by: Michael Walle Tested-by: Marek Szyprowski Tested-by: Cosmin Tanislav Link: https://patch.msgid.link/20251219152813.1893982-1-alexander.stein@ew.tq-group.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/serial_base_bus.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/tty') diff --git a/drivers/tty/serial/serial_base_bus.c b/drivers/tty/serial/serial_base_bus.c index 8e891984cdc0..1e1ad28d83fc 100644 --- a/drivers/tty/serial/serial_base_bus.c +++ b/drivers/tty/serial/serial_base_bus.c @@ -74,6 +74,7 @@ static int serial_base_device_init(struct uart_port *port, dev->parent = parent_dev; dev->bus = &serial_base_bus_type; dev->release = release; + dev->of_node_reused = true; device_set_node(dev, fwnode_handle_get(dev_fwnode(parent_dev))); -- cgit v1.2.3 From c3ca8a0aac832fe8047608bb2ae2cca314c6d717 Mon Sep 17 00:00:00 2001 From: Claudiu Beznea Date: Wed, 17 Dec 2025 15:57:59 +0200 Subject: serial: sh-sci: Check that the DMA cookie is valid The driver updates struct sci_port::tx_cookie to zero right before the TX work is scheduled, or to -EINVAL when DMA is disabled. dma_async_is_complete(), called through dma_cookie_status() (and possibly through dmaengine_tx_status()), considers cookies valid only if they have values greater than or equal to 1. Passing zero or -EINVAL to dmaengine_tx_status() before any TX DMA transfer has started leads to an incorrect TX status being reported, as the cookie is invalid for the DMA subsystem. This may cause long wait times when the serial device is opened for configuration before any TX activity has occurred. Check that the TX cookie is valid before passing it to dmaengine_tx_status(). Fixes: 7cc0e0a43a91 ("serial: sh-sci: Check if TX data was written to device in .tx_empty()") Cc: stable Signed-off-by: Claudiu Beznea Link: https://patch.msgid.link/20251217135759.402015-1-claudiu.beznea.uj@bp.renesas.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/sh-sci.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/tty') diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index 53edbf1d8963..fbfe5575bd3c 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -1914,7 +1914,7 @@ static void sci_dma_check_tx_occurred(struct sci_port *s) struct dma_tx_state state; enum dma_status status; - if (!s->chan_tx) + if (!s->chan_tx || s->cookie_tx <= 0) return; status = dmaengine_tx_status(s->chan_tx, s->cookie_tx, &state); -- cgit v1.2.3 From 267ee93c417e685d9f8e079e41c70ba6ee4df5a5 Mon Sep 17 00:00:00 2001 From: "j.turek" Date: Sun, 21 Dec 2025 11:32:21 +0100 Subject: serial: xilinx_uartps: fix rs485 delay_rts_after_send RTS line control with delay should be triggered when there is no more bytes in kfifo and hardware buffer is empty. Without this patch RTS control is scheduled right after feeding hardware buffer and this is too early. RTS line may change state before hardware buffer is empty. With this patch delayed RTS state change is triggered when function cdns_uart_handle_tx is called from cdns_uart_isr on CDNS_UART_IXR_TXEMPTY exactly when hardware completed transmission Fixes: fccc9d9233f9 ("tty: serial: uartps: Add rs485 support to uartps driver") Cc: stable Link: https://patch.msgid.link/20251221103221.1971125-1-jakub.turek@elsta.tech Signed-off-by: Jakub Turek Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/xilinx_uartps.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) (limited to 'drivers/tty') diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c index c793fc74c26b..c593d20a1b5b 100644 --- a/drivers/tty/serial/xilinx_uartps.c +++ b/drivers/tty/serial/xilinx_uartps.c @@ -428,10 +428,17 @@ static void cdns_uart_handle_tx(void *dev_id) struct tty_port *tport = &port->state->port; unsigned int numbytes; unsigned char ch; + ktime_t rts_delay; if (kfifo_is_empty(&tport->xmit_fifo) || uart_tx_stopped(port)) { /* Disable the TX Empty interrupt */ writel(CDNS_UART_IXR_TXEMPTY, port->membase + CDNS_UART_IDR); + /* Set RTS line after delay */ + if (cdns_uart->port->rs485.flags & SER_RS485_ENABLED) { + cdns_uart->tx_timer.function = &cdns_rs485_rx_callback; + rts_delay = ns_to_ktime(cdns_calc_after_tx_delay(cdns_uart)); + hrtimer_start(&cdns_uart->tx_timer, rts_delay, HRTIMER_MODE_REL); + } return; } @@ -448,13 +455,6 @@ static void cdns_uart_handle_tx(void *dev_id) /* Enable the TX Empty interrupt */ writel(CDNS_UART_IXR_TXEMPTY, cdns_uart->port->membase + CDNS_UART_IER); - - if (cdns_uart->port->rs485.flags & SER_RS485_ENABLED && - (kfifo_is_empty(&tport->xmit_fifo) || uart_tx_stopped(port))) { - hrtimer_update_function(&cdns_uart->tx_timer, cdns_rs485_rx_callback); - hrtimer_start(&cdns_uart->tx_timer, - ns_to_ktime(cdns_calc_after_tx_delay(cdns_uart)), HRTIMER_MODE_REL); - } } /** -- cgit v1.2.3 From fb47423dc7bf43301048d77289ce0114959de4de Mon Sep 17 00:00:00 2001 From: Praveen Talari Date: Thu, 8 Jan 2026 09:40:06 +0530 Subject: serial: qcom_geni: Fix BT failure regression on RB2 platform Commit 10904d725f6e ("serial: qcom-geni: Enable PM runtime for serial driver") caused BT init to fail during bootup on the RB2 platform, preventing proper BT initialization. However, BT works correctly after bootup completes. The issue occurs when runtime PM is enabled and uart_add_one_port() is called before wakeup IRQ setup. The uart_add_one_port() call activates the device through runtime PM, which configures GPIOs to the "qup_x" pinmux function during runtime resume. When wakeup IRQ registration happens afterward using dev_pm_set_dedicated_wake_irq(), these GPIOs are reset back to the "gpio" pinmux function, which impacts the RX GPIO and leads to Bluetooth failures. Fix this by ensuring wakeup IRQ setup is completed before calling uart_add_one_port() to prevent the pinmux function conflict. Fixes: 10904d725f6e ("serial: qcom-geni: Enable PM runtime for serial driver") Reported-by: Dmitry Baryshkov Closes: https://lore.kernel.org/all/20251110101043.2108414-4-praveen.talari@oss.qualcomm.com/ Tested-by: Dmitry Baryshkov Reviewed-by: Dmitry Baryshkov Signed-off-by: Praveen Talari Link: https://patch.msgid.link/20260108041006.1874757-1-praveen.talari@oss.qualcomm.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/qcom_geni_serial.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) (limited to 'drivers/tty') diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c index 6ce6528f5c10..e6b0a55f0cfb 100644 --- a/drivers/tty/serial/qcom_geni_serial.c +++ b/drivers/tty/serial/qcom_geni_serial.c @@ -1888,12 +1888,6 @@ static int qcom_geni_serial_probe(struct platform_device *pdev) if (ret) goto error; - devm_pm_runtime_enable(port->se.dev); - - ret = uart_add_one_port(drv, uport); - if (ret) - goto error; - if (port->wakeup_irq > 0) { device_init_wakeup(&pdev->dev, true); ret = dev_pm_set_dedicated_wake_irq(&pdev->dev, @@ -1901,11 +1895,16 @@ static int qcom_geni_serial_probe(struct platform_device *pdev) if (ret) { device_init_wakeup(&pdev->dev, false); ida_free(&port_ida, uport->line); - uart_remove_one_port(drv, uport); goto error; } } + devm_pm_runtime_enable(port->se.dev); + + ret = uart_add_one_port(drv, uport); + if (ret) + goto error; + return 0; error: -- cgit v1.2.3 From 27aff0a56b3c77ea1a73641c9b3c4172a8f7238f Mon Sep 17 00:00:00 2001 From: Marnix Rijnart Date: Mon, 12 Jan 2026 01:08:23 +0100 Subject: serial: 8250_pci: Fix broken RS485 for F81504/508/512 Fintek F81504/508/512 can support both RTS_ON_SEND and RTS_AFTER_SEND, but pci_fintek_rs485_supported only announces the former. This makes it impossible to unset SER_RS485_RTS_ON_SEND from userspace because of uart_sanitize_serial_rs485(). Some devices with these chips need RTS low on TX, so they are effectively broken. Fix this by announcing the support for SER_RS485_RTS_AFTER_SEND, similar to commit 068d35a7be65 ("serial: sc16is7xx: announce support for SER_RS485_RTS_ON_SEND"). Fixes: 4afeced55baa ("serial: core: fix sanitizing check for RTS settings") Cc: stable Signed-off-by: Marnix Rijnart Link: https://patch.msgid.link/20260112000931.61703-1-marnix.rijnart@iwell.eu Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_pci.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/tty') diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c index c5a932f48f74..3efe075ef7b2 100644 --- a/drivers/tty/serial/8250/8250_pci.c +++ b/drivers/tty/serial/8250/8250_pci.c @@ -1658,7 +1658,7 @@ static int pci_fintek_rs485_config(struct uart_port *port, struct ktermios *term } static const struct serial_rs485 pci_fintek_rs485_supported = { - .flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND, + .flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | SER_RS485_RTS_AFTER_SEND, /* F81504/508/512 does not support RTS delay before or after send */ }; -- cgit v1.2.3 From 32f37e57583f869140cff445feedeea8a5fea986 Mon Sep 17 00:00:00 2001 From: Krzysztof Kozlowski Date: Fri, 23 Jan 2026 08:21:40 +0100 Subject: serial: Fix not set tty->port race condition Revert commit bfc467db60b7 ("serial: remove redundant tty_port_link_device()") because the tty_port_link_device() is not redundant: the tty->port has to be confured before we call uart_configure_port(), otherwise user-space can open console without TTY linked to the driver. This tty_port_link_device() was added explicitly to avoid this exact issue in commit fb2b90014d78 ("tty: link tty and port before configuring it as console"), so offending commit basically reverted the fix saying it is redundant without addressing the actual race condition presented there. Reproducible always as tty->port warning on Qualcomm SoC with most of devices disabled, so with very fast boot, and one serial device being the console: printk: legacy console [ttyMSM0] enabled printk: legacy console [ttyMSM0] enabled printk: legacy bootconsole [qcom_geni0] disabled printk: legacy bootconsole [qcom_geni0] disabled ------------[ cut here ]------------ tty_init_dev: ttyMSM driver does not set tty->port. This would crash the kernel. Fix the driver! WARNING: drivers/tty/tty_io.c:1414 at tty_init_dev.part.0+0x228/0x25c, CPU#2: systemd/1 Modules linked in: socinfo tcsrcc_eliza gcc_eliza sm3_ce fuse ipv6 CPU: 2 UID: 0 PID: 1 Comm: systemd Tainted: G S 6.19.0-rc4-next-20260108-00024-g2202f4d30aa8 #73 PREEMPT Tainted: [S]=CPU_OUT_OF_SPEC Hardware name: Qualcomm Technologies, Inc. Eliza (DT) ... tty_init_dev.part.0 (drivers/tty/tty_io.c:1414 (discriminator 11)) (P) tty_open (arch/arm64/include/asm/atomic_ll_sc.h:95 (discriminator 3) drivers/tty/tty_io.c:2073 (discriminator 3) drivers/tty/tty_io.c:2120 (discriminator 3)) chrdev_open (fs/char_dev.c:411) do_dentry_open (fs/open.c:962) vfs_open (fs/open.c:1094) do_open (fs/namei.c:4634) path_openat (fs/namei.c:4793) do_filp_open (fs/namei.c:4820) do_sys_openat2 (fs/open.c:1391 (discriminator 3)) ... Starting Network Name Resolution... Apparently the flow with this small Yocto-based ramdisk user-space is: driver (qcom_geni_serial.c): user-space: ============================ =========== qcom_geni_serial_probe() uart_add_one_port() serial_core_register_port() serial_core_add_one_port() uart_configure_port() register_console() | | open console | ... | tty_init_dev() | driver->ports[idx] is NULL | tty_port_register_device_attr_serdev() tty_port_link_device() <- set driver->ports[idx] Fixes: bfc467db60b7 ("serial: remove redundant tty_port_link_device()") Cc: stable@vger.kernel.org Signed-off-by: Krzysztof Kozlowski Reviewed-by: Jiri Slaby Link: https://patch.msgid.link/20260123072139.53293-2-krzysztof.kozlowski@oss.qualcomm.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/serial_core.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'drivers/tty') diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index 9930023e924c..2805cad10511 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -3074,6 +3074,12 @@ static int serial_core_add_one_port(struct uart_driver *drv, struct uart_port *u if (uport->cons && uport->dev) of_console_check(uport->dev->of_node, uport->cons->name, uport->line); + /* + * TTY port has to be linked with the driver before register_console() + * in uart_configure_port(), because user-space could open the console + * immediately after. + */ + tty_port_link_device(port, drv->tty_driver, uport->line); uart_configure_port(drv, state, uport); port->console = uart_console(uport); -- cgit v1.2.3