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2025-01-22Revert "serial: 8250: Revert "drop lockdep annotation from ↵Greg Kroah-Hartman
serial8250_clear_IER()"" This reverts commit 422c9727b07f9f86e2ec11c56622e566221591cc. kernel test robot has found problems with this commit so revert it for now. Link: https://lore.kernel.org/r/202501221029.fb0d574d-lkp@intel.com Reported-by: kernel test robot <oliver.sang@intel.com> Closes: https://lore.kernel.org/oe-lkp/202501221029.fb0d574d-lkp@intel.com Cc: John Ogness <john.ogness@linutronix.de> Cc: Petr Mladek <pmladek@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-17serial: sh-sci: Increment the runtime usage counter for the earlycon deviceClaudiu Beznea
In the sh-sci driver, serial ports are mapped to the sci_ports[] array, with earlycon mapped at index zero. The uart_add_one_port() function eventually calls __device_attach(), which, in turn, calls pm_request_idle(). The identified code path is as follows: uart_add_one_port() -> serial_ctrl_register_port() -> serial_core_register_port() -> serial_core_port_device_add() -> serial_base_port_add() -> device_add() -> bus_probe_device() -> device_initial_probe() -> __device_attach() -> // ... if (dev->p->dead) { // ... } else if (dev->driver) { // ... } else { // ... pm_request_idle(dev); // ... } The earlycon device clocks are enabled by the bootloader. However, the pm_request_idle() call in __device_attach() disables the SCI port clocks while earlycon is still active. The earlycon write function, serial_console_write(), calls sci_poll_put_char() via serial_console_putchar(). If the SCI port clocks are disabled, writing to earlycon may sometimes cause the SR.TDFE bit to remain unset indefinitely, causing the while loop in sci_poll_put_char() to never exit. On single-core SoCs, this can result in the system being blocked during boot when this issue occurs. To resolve this, increment the runtime PM usage counter for the earlycon SCI device before registering the UART port. Fixes: 0b0cced19ab1 ("serial: sh-sci: Add CONFIG_SERIAL_EARLYCON support") Cc: stable@vger.kernel.org Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Link: https://lore.kernel.org/r/20250116182249.3828577-6-claudiu.beznea.uj@bp.renesas.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-17serial: sh-sci: Clean sci_ports[0] after at earlycon exitClaudiu Beznea
The early_console_setup() function initializes sci_ports[0].port with an object of type struct uart_port obtained from the struct earlycon_device passed as an argument to early_console_setup(). Later, during serial port probing, the serial port used as earlycon (e.g., port A) might be remapped to a different position in the sci_ports[] array, and a different serial port (e.g., port B) might be assigned to slot 0. For example: sci_ports[0] = port B sci_ports[X] = port A In this scenario, the new port mapped at index zero (port B) retains the data associated with the earlycon configuration. Consequently, after the Linux boot process, any access to the serial port now mapped to sci_ports[0] (port B) will block the original earlycon port (port A). To address this, introduce an early_console_exit() function to clean up sci_ports[0] when earlycon is exited. To prevent the cleanup of sci_ports[0] while the serial device is still being used by earlycon, introduce the struct sci_port::probing flag and account for it in early_console_exit(). Fixes: 0b0cced19ab1 ("serial: sh-sci: Add CONFIG_SERIAL_EARLYCON support") Cc: stable@vger.kernel.org Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Link: https://lore.kernel.org/r/20250116182249.3828577-5-claudiu.beznea.uj@bp.renesas.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-17serial: sh-sci: Do not probe the serial port if its slot in sci_ports[] is ↵Claudiu Beznea
in use In the sh-sci driver, sci_ports[0] is used by earlycon. If the earlycon is still active when sci_probe() is called and the new serial port is supposed to map to sci_ports[0], return -EBUSY to prevent breaking the earlycon. This situation should occurs in debug scenarios, and users should be aware of the potential conflict. Fixes: 0b0cced19ab1 ("serial: sh-sci: Add CONFIG_SERIAL_EARLYCON support") Cc: stable@vger.kernel.org Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Link: https://lore.kernel.org/r/20250116182249.3828577-4-claudiu.beznea.uj@bp.renesas.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-17serial: sh-sci: Move runtime PM enable to sci_probe_single()Claudiu Beznea
Relocate the runtime PM enable operation to sci_probe_single(). This change prepares the codebase for upcoming fixes. While at it, replace the existing logic with a direct call to devm_pm_runtime_enable() and remove sci_cleanup_single(). The devm_pm_runtime_enable() function automatically handles disabling runtime PM during driver removal. Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Link: https://lore.kernel.org/r/20250116182249.3828577-3-claudiu.beznea.uj@bp.renesas.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-17serial: sh-sci: Drop __initdata macro for port_cfgClaudiu Beznea
The port_cfg object is used by serial_console_write(), which serves as the write function for the earlycon device. Marking port_cfg as __initdata causes it to be freed after kernel initialization, resulting in earlycon becoming unavailable thereafter. Remove the __initdata macro from port_cfg to resolve this issue. Fixes: 0b0cced19ab1 ("serial: sh-sci: Add CONFIG_SERIAL_EARLYCON support") Cc: stable@vger.kernel.org Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Fixes: 0b0cced19ab15c9e ("serial: sh-sci: Add CONFIG_SERIAL_EARLYCON support") Link: https://lore.kernel.org/r/20250116182249.3828577-2-claudiu.beznea.uj@bp.renesas.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-17serial: kgdb_nmi: Remove unused knock codeDr. David Alan Gilbert
kgdb_nmi_poll_knock() has been unused since it was added in 2013 in commit 0c57dfcc6c1d ("tty/serial: Add kgdb_nmi driver") Remove it, the static helpers, and module parameters it used. (The comment explaining why it might be used sounds sensible, but it's never been wired up, perhaps it's worth doing somewhere?) Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org> Link: https://lore.kernel.org/r/20250112135759.105541-1-linux@treblig.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-13tty: xilinx_uartps: split sysrq handlingSean Anderson
lockdep detects the following circular locking dependency: CPU 0 CPU 1 ========================== ============================ cdns_uart_isr() printk() uart_port_lock(port) console_lock() cdns_uart_console_write() if (!port->sysrq) uart_port_lock(port) uart_handle_break() port->sysrq = ... uart_handle_sysrq_char() printk() console_lock() The fixed commit attempts to avoid this situation by only taking the port lock in cdns_uart_console_write if port->sysrq unset. However, if (as shown above) cdns_uart_console_write runs before port->sysrq is set, then it will try to take the port lock anyway. This may result in a deadlock. Fix this by splitting sysrq handling into two parts. We use the prepare helper under the port lock and defer handling until we release the lock. Fixes: 74ea66d4ca06 ("tty: xuartps: Improve sysrq handling") Signed-off-by: Sean Anderson <sean.anderson@linux.dev> Cc: stable@vger.kernel.org # c980248179d: serial: xilinx_uartps: Use port lock wrappers Acked-by: John Ogness <john.ogness@linutronix.de> Link: https://lore.kernel.org/r/20250110213822.2107462-1-sean.anderson@linux.dev Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-13Merge 6.13-rc7 into tty-nextGreg Kroah-Hartman
We need the serial driver fixes in here to build on top of. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-13Merge 6.13-rc7 into driver-core-nextGreg Kroah-Hartman
We need the debugfs / driver-core fixes in here as well for testing and to build on top of. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-10serial: 8250: Revert "drop lockdep annotation from serial8250_clear_IER()"John Ogness
The 8250 driver no longer depends on @oops_in_progress and will no longer violate the port->lock locking constraints. This reverts commit 3d9e6f556e235ddcdc9f73600fdd46fe1736b090. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20250107212702.169493-7-john.ogness@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-10serial: 8250: Switch to nbcon consoleJohn Ogness
Implement the necessary callbacks to switch the 8250 console driver to perform as an nbcon console. Add implementations for the nbcon console callbacks: ->write_atomic() ->write_thread() ->device_lock() ->device_unlock() and add CON_NBCON to the initial @flags. All register access in the callbacks are within unsafe sections. The ->write_atomic() and ->write_thread() callbacks allow safe handover/takeover per byte and add a preceding newline if they take over from another context mid-line. For the ->write_atomic() callback, a new irq_work is used to defer modem control since it may be called from a context that does not allow waking up tasks. Note: A new __serial8250_clear_IER() is introduced for direct clearing of UART_IER. This will allow to restore the lockdep check to serial8250_clear_IER() in a follow-up commit. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Tested-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20250107212702.169493-6-john.ogness@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-10serial: 8250: Provide flag for IER toggling for RS485John Ogness
For RS485 mode, if SER_RS485_RX_DURING_TX is not available, the console ->write() callback needs to enable/disable Tx. It does this by calling the ->rs485_start_tx() and ->rs485_stop_tx() callbacks. However, some of these callbacks also disable/enable interrupts and makes power management calls. This causes 2 problems for console writing: 1. A console write can occur in contexts that are illegal for pm_runtime_*(). It is not even necessary for console writing to use pm_runtime_*() because a console already does this in serial8250_console_setup() and serial8250_console_exit(). 2. The console ->write() callback already handles disabling/enabling the interrupts by properly restoring the previous IER value. Add an argument @toggle_ier to the ->rs485_start_tx() and ->rs485_stop_tx() callbacks to specify if they may disable/enable receive interrupts while using pm_runtime_*(). Console writing will not allow the toggling. For all call sites other than console writing there is no functional change. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20250107212702.169493-5-john.ogness@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-10serial: 8250: Use high-level writing function for FIFOJohn Ogness
Currently serial8250_console_fifo_write() directly writes into the UART_TX register rather than using the high-level function serial8250_console_putchar(). This is because serial8250_console_putchar() waits for the holding register to become empty, which would defeat the purpose of the FIFO code. Move the LSR_THRE waiting to a new function serial8250_console_wait_putchar() so that the FIFO code can use serial8250_console_putchar(). This will be particularly important for a follow-up commit, where output bytes are inspected to track newlines. This is only refactoring and has no functional change. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20250107212702.169493-4-john.ogness@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-10serial: 8250: Use frame time to determine timeoutJohn Ogness
Rather than using a hard-coded per-character Tx-timeout of 10ms, use the frame time to determine a timeout value. The value is doubled to ensure that a timeout is only hit during unexpected circumstances. Since the frame time may not be available during early printing, the previous 10ms value is kept as a fallback. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20250107212702.169493-3-john.ogness@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-10serial: 8250: Adjust the timeout for FIFO modeJohn Ogness
After a console has written a record into UART_TX, it uses wait_for_xmitr() to wait until the data has been sent out before returning. However, wait_for_xmitr() will timeout after 10ms, regardless if the data has been transmitted or not. For single bytes, this timeout is sufficient even at very slow baud rates, such as 1200bps. However, when FIFO mode is used, there may be 64 bytes pushed into the FIFO at once. At a baud rate of 115200bps, the 10ms timeout is still sufficient. But when using lower baud rates (such as 57600bps), the timeout is _not_ sufficient. This causes longer lines to be cut off, resulting in lost and horribly misformatted output on the console. When using FIFO mode, take the number of bytes into account to determine an appropriate maximum timeout. Increasing the timeout does not affect performance since ideally the timeout never occurs. Fixes: 8f3631f0f6eb ("serial/8250: Use fifo in 8250 console driver") Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Wander Lairson Costa <wander@redhat.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20250107212702.169493-2-john.ogness@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-10tty: atmel_serial: Use of_property_present() for non-boolean propertiesRob Herring (Arm)
The use of of_property_read_bool() for non-boolean properties is deprecated in favor of of_property_present() when testing for property presence. As of_property_present() returns a boolean, use that directly and simplify the code a bit while we're here. Signed-off-by: Rob Herring (Arm) <robh@kernel.org> Acked-by: Richard Genoud <richard.genoud@bootlin.com> Reviewed-by: Nicolas Ferre <nicolas.ferre@microchip.com> Link: https://lore.kernel.org/r/20250109182053.3970547-1-robh@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-10serial: sc16is7xx: Add polling mode if no IRQ pin is availableAndre Werner
Fall back to polling mode if no interrupt is configured because there is no possibility to connect the interrupt pin. If "interrupts" property is missing in devicetree the driver uses a delayed worker to pull the state of interrupt status registers. Signed-off-by: Andre Werner <andre.werner@systec-electronic.com> Link: https://lore.kernel.org/r/20250110073104.1029633-2-andre.werner@systec-electronic.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-10tty: serial: atmel: make it selectable for ARCH_LAN969XRobert Marko
LAN969x uses the Atmel serial, so make it selectable for ARCH_LAN969X. Signed-off-by: Robert Marko <robert.marko@sartura.hr> Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com> Link: https://lore.kernel.org/r/20250108131045.40642-3-robert.marko@sartura.hr Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-07tty: serial: fsl_lpuart: flush RX and TX FIFO when lpuart shutdownSherry Sun
Need to flush UART RX and TX FIFO when lpuart is shutting down to make sure restore a clean data transfer environment. Signed-off-by: Sherry Sun <sherry.sun@nxp.com> Link: https://lore.kernel.org/r/20250107074834.3115230-1-sherry.sun@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-07tty: serial: fsl_lpuart: increase maximum uart_nr to 12Sherry Sun
Some SoCs like the i.MX943 have aliases for up to 12 UARTs, need to increase UART_NR from 8 to 12 to support lpuart9-12 to avoid initialization failures. Signed-off-by: Sherry Sun <sherry.sun@nxp.com> Link: https://lore.kernel.org/r/20250103071154.3070924-1-sherry.sun@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-03driver core: Constify API device_find_child() and adapt for various usagesZijun Hu
Constify the following API: struct device *device_find_child(struct device *dev, void *data, int (*match)(struct device *dev, void *data)); To : struct device *device_find_child(struct device *dev, const void *data, device_match_t match); typedef int (*device_match_t)(struct device *dev, const void *data); with the following reasons: - Protect caller's match data @*data which is for comparison and lookup and the API does not actually need to modify @*data. - Make the API's parameters (@match)() and @data have the same type as all of other device finding APIs (bus|class|driver)_find_device(). - All kinds of existing device match functions can be directly taken as the API's argument, they were exported by driver core. Constify the API and adapt for various existing usages. BTW, various subsystem changes are squashed into this commit to meet 'git bisect' requirement, and this commit has the minimal and simplest changes to complement squashing shortcoming, and that may bring extra code improvement. Reviewed-by: Alison Schofield <alison.schofield@intel.com> Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Acked-by: Uwe Kleine-König <ukleinek@kernel.org> # for drivers/pwm Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> Link: https://lore.kernel.org/r/20241224-const_dfc_done-v5-4-6623037414d4@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-23serial: amba-pl011: Fix RTS handling in RS485 modeMiroslav Ondra
Data loss on serial line was observed during communication through serial ports ttyAMA1 and ttyAMA2 interconnected via RS485 transcievers. Both ports are in one BCM2711 (Compute Module CM40) and they share the same interrupt line. The problem is caused by long waiting for tx queue flush in the function pl011_rs485_tx_stop. Udelay or mdelay are used to wait. The function is called from the interrupt handler. If multiple devices share a single interrupt line, late processing of pending interrupts and data loss may occur. When operation of both devices are synchronous, collisions are quite often. This rework is based on the method used in tty/serial/imx.c Use hrtimer instead of udelay and mdelay calls. Replace simple bool variable rs485_tx_started by 4-state variable rs485_tx_state. Tested-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Signed-off-by: Miroslav Ondra <ondra@faster.cz> Link: https://lore.kernel.org/r/20241221-amba-rts-v3-1-d3d444681419@faster.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-23serial: stm32: use port lock wrappers for break controlBen Wolsieffer
Commit 30e945861f3b ("serial: stm32: add support for break control") added another usage of the port lock, but was merged on the same day as c5d06662551c ("serial: stm32: Use port lock wrappers"), therefore the latter did not update this usage to use the port lock wrappers. Fixes: c5d06662551c ("serial: stm32: Use port lock wrappers") Cc: stable <stable@kernel.org> Signed-off-by: Ben Wolsieffer <ben.wolsieffer@hefring.com> Reviewed-by: John Ogness <john.ogness@linutronix.de> Link: https://lore.kernel.org/r/20241216145323.111612-1-ben.wolsieffer@hefring.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-23serial: imx: Use uart_port_lock_irq() instead of uart_port_lock()Xiaolei Wang
When executing 'echo mem > /sys/power/state', the following deadlock occurs. Since there is output during the serial port entering the suspend process, the suspend will be interrupted, resulting in the nesting of locks. Therefore, use uart_port_lock_irq() instead of uart_port_unlock(). WARNING: inconsistent lock state 6.12.0-rc2-00002-g3c199ed5bd64-dirty #23 Not tainted -------------------------------- inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage. sh/494 [HC0[0]:SC0[0]:HE1:SE1] takes: c4db5850 (&port_lock_key){?.-.}-{3:3}, at: imx_uart_enable_wakeup+0x14/0x254 {IN-HARDIRQ-W} state was registered at: lock_acquire+0x104/0x348 _raw_spin_lock+0x48/0x84 imx_uart_int+0x14/0x4dc __handle_irq_event_percpu+0xac/0x2fc handle_irq_event_percpu+0xc/0x40 handle_irq_event+0x38/0x8c handle_fasteoi_irq+0xb4/0x1b8 handle_irq_desc+0x1c/0x2c gic_handle_irq+0x6c/0xa0 generic_handle_arch_irq+0x2c/0x64 call_with_stack+0x18/0x20 __irq_svc+0x9c/0xbc _raw_spin_unlock_irqrestore+0x2c/0x48 uart_write+0xd8/0x3a0 do_output_char+0x1a8/0x1e4 n_tty_write+0x224/0x440 file_tty_write.constprop.0+0x124/0x250 do_iter_readv_writev+0x100/0x1e0 vfs_writev+0xc4/0x448 do_writev+0x68/0xf8 ret_fast_syscall+0x0/0x1c irq event stamp: 31593 hardirqs last enabled at (31593): [<c1150e48>] _raw_spin_unlock_irqrestore+0x44/0x48 hardirqs last disabled at (31592): [<c07f32f0>] clk_enable_lock+0x60/0x120 softirqs last enabled at (30334): [<c012d1d4>] handle_softirqs+0x2cc/0x478 softirqs last disabled at (30325): [<c012d510>] __irq_exit_rcu+0x120/0x15c other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&port_lock_key); <Interrupt> lock(&port_lock_key); Fixes: 3c199ed5bd64 ("serial: imx: Grab port lock in imx_uart_enable_wakeup()") Signed-off-by: Xiaolei Wang <xiaolei.wang@windriver.com> Reviewed-by: Lucas Stach <l.stach@pengutronix.de> Reviewed-by: Fabio Estevam <festevam@gmail.com> Link: https://lore.kernel.org/r/20241210233613.2881264-1-xiaolei.wang@windriver.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-23tty: serial: 8250: Fix another runtime PM usage counter underflowIlpo Järvinen
The commit f9b11229b79c ("serial: 8250: Fix PM usage_count for console handover") fixed one runtime PM usage counter balance problem that occurs because .dev is not set during univ8250 setup preventing call to pm_runtime_get_sync(). Later, univ8250_console_exit() will trigger the runtime PM usage counter underflow as .dev is already set at that time. Call pm_runtime_get_sync() to balance the RPM usage counter also in serial8250_register_8250_port() before trying to add the port. Reported-by: Borislav Petkov (AMD) <bp@alien8.de> Fixes: bedb404e91bb ("serial: 8250_port: Don't use power management for kernel console") Cc: stable <stable@kernel.org> Tested-by: Borislav Petkov (AMD) <bp@alien8.de> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20241210170120.2231-1-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-23serial: 8250: Explain the role of @read_status_maskJohn Ogness
The role of @read_status_mask has changed over time and seems to still cause confusion. This can be expected since there is zero documentation about this driver-specific variable. Add comments to the initialization of @read_status_mask to clarify its role. Signed-off-by: John Ogness <john.ogness@linutronix.de> Link: https://lore.kernel.org/r/20241216171244.12783-5-john.ogness@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-23serial: 8250: Never adjust UART_LSR_DR in @read_status_maskJohn Ogness
The CREAD feature of termios is implemented by setting/clearing UART_LSR_DR within @ignore_status_mask. For this feature to function correctly, it requires that UART_LSR_DR is never masked (unset) in @read_status_mask so that uart_insert_char() can properly drop the character if CREAD is disabled. Currently there are code paths that clear/set UART_LSR_DR from @read_status_mask at times. This appears to be a relic from Linux 1.1.60, where @read_status_mask could be used to mask all UART_LSR reading. However, since Linux 2.1.8 that is no longer the case. Now if UART_LSR_DR is cleared from @read_status_mask, received characters may not be dropped even though CREAD is disabled. This can be seen when: - CREAD is disabled (UART_LSR_DR is set in @ignore_status_mask) - LSR has an error bit set from UART_LSR_BRK_ERROR_BITS (and that error is not ignored via @ignore_status_mask) - UART_LSR_DR is cleared in @read_status_mask In this case characters will be inserted into the tty buffer even though they should be ignored. Remove all setting/clearing of UART_LSR_DR for @read_status_mask except for its initialization. Signed-off-by: John Ogness <john.ogness@linutronix.de> Link: https://lore.kernel.org/r/20241216171244.12783-4-john.ogness@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-23serial: 8250: Do not set UART_LSR_THRE in @read_status_maskJohn Ogness
Since Linux 2.1.8 @read_status_mask is no longer used as a general control of which bits are used from the LSR register. Instead it has become an additional mask applied to @ignore_status_mask. Since UART_LSR_THRE is never set for @ignore_status_mask, it serves no purpose to set it for @read_status_mask. In fact, it propagates the misconception that @read_status_mask can be used as a general mask for LSR bits. Do not set UART_LSR_THRE for @read_status_mask. Signed-off-by: John Ogness <john.ogness@linutronix.de> Link: https://lore.kernel.org/r/20241216171244.12783-3-john.ogness@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-23serial: 8250: Use @ier bits to determine if Rx is stoppedJohn Ogness
Commit f19c3f6c8109 ("serial: 8250_port: Don't service RX FIFO if throttled") uses @read_status_mask (bit UART_LSR_DR) to determine if Rx has been stopped. However, the bit UART_LSR_DR is not managed properly in @read_status_mask for all Rx stop/start situations and is therefore not suitable for this purpose. Use the UART_IER_RLSI and UART_IER_RDI bits in @ier instead, as this is already common in 8250-variants and drivers. Signed-off-by: John Ogness <john.ogness@linutronix.de> Link: https://lore.kernel.org/r/20241216171244.12783-2-john.ogness@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-238250: microchip: pci1xxxx: Add workaround for RTS bit toggleRengarajan S
In the B0 revision, the RTS pin remains high due to incorrect hardware mapping. To address this issue, enable auto-direction control with the RTS bit in ADCL_CFG_REG. This configuration ensures that the RTS pin goes low when the terminal is opened and high when the terminal is closed. Additionally, we reset the step counter for Rx and Tx engines by writing into FRAC_DIV_CFG_REG. Signed-off-by: Rengarajan S <rengarajan.s@microchip.com> Link: https://lore.kernel.org/r/20241218094017.18290-1-rengarajan.s@microchip.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-16Merge 6.13-rc3 into tty-nextGreg Kroah-Hartman
We need the serial fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-14Merge tag 'tty-6.13-rc3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull serial driver fixes from Greg KH: "Here are two small serial driver fixes for 6.13-rc3. They are: - ioport build fallout fix for the 8250 port driver that should resolve Guenter's runtime problems - sh-sci driver bugfix for a reported problem Both of these have been in linux-next for a while with no reported issues" * tag 'tty-6.13-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: tty: serial: Work around warning backtrace in serial8250_set_defaults serial: sh-sci: Check if TX data was written to device in .tx_empty()
2024-12-14tty: serial: extract uart_change_port() from uart_set_info()Jiri Slaby (SUSE)
This "change_port" part of uart_set_info() is for no good reason inlined there. It makes the function rather hard to read. Therefore, extract it to a separate function. This allows for flattening the ifs (with short path "return"s) and avoiding two levels of indentation. Both making the code really flat and comprehesible. Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20241211074933.92973-4-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-14tty: serial: get rid of exit label from uart_set_info()Jiri Slaby (SUSE)
The label is unneeded since 7ba2e769825f (tty: Split the serial_core helpers for setserial into two). Until then, there was a lock held in uart_set_info(). Now it is not, so we can remove the label. This involves reordering the code, so that it is clear what values are returned, where and why. Until now, it was really hard to follow. The "change_port" part of the function is extracted into a separate function in the next patch. This patch makes the transition there easier too. Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20241211074933.92973-3-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-14tty: serial_core: use more guard(mutex)Jiri Slaby (SUSE)
Simplify 4 more functions using guard(mutex): uart_get_info(), console_store(), serial_core_add_one_port(), and serial_core_register_port(). Especially console_store() is now much less convoluted. In the others, we save some goto-s and even local variables are dropped in some. Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20241211074933.92973-2-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-14serial: altera_uart: Use KBUILD_MODNAMETobias Klauser
There is no need to redefine the driver name. Use KBUILD_MODNAME and get rid of DRV_NAME altogether. Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Link: https://lore.kernel.org/r/20241205091138.25894-1-tklauser@distanz.ch Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-06tty: serial: Work around warning backtrace in serial8250_set_defaultsGuenter Roeck
Commit 7c7e6c8924e7 ("tty: serial: handle HAS_IOPORT dependencies") triggers warning backtraces on a number of platforms which don't support IO ports. WARNING: CPU: 0 PID: 0 at drivers/tty/serial/8250/8250_port.c:470 serial8250_set_defaults+0x148/0x1d8 Unsupported UART type 0 The problem is seen because serial8250_set_defaults() is called for all members of the serial8250_ports[] array even if that array is not initialized. Work around the problem by only displaying the warning if the port type is not 0 (UPIO_PORT) or if iobase is set for the port. Fixes: 7c7e6c8924e7 ("tty: serial: handle HAS_IOPORT dependencies") Acked-by: Arnd Bergmann <arnd@arndb.de> Cc: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Stafford Horne <shorne@gmail.com> Link: https://lore.kernel.org/r/20241205143033.2695333-1-linux@roeck-us.net Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-04serial: sh-sci: Check if TX data was written to device in .tx_empty()Claudiu Beznea
On the Renesas RZ/G3S, when doing suspend to RAM, the uart_suspend_port() is called. The uart_suspend_port() calls 3 times the struct uart_port::ops::tx_empty() before shutting down the port. According to the documentation, the struct uart_port::ops::tx_empty() API tests whether the transmitter FIFO and shifter for the port is empty. The Renesas RZ/G3S SCIFA IP reports the number of data units stored in the transmit FIFO through the FDR (FIFO Data Count Register). The data units in the FIFOs are written in the shift register and transmitted from there. The TEND bit in the Serial Status Register reports if the data was transmitted from the shift register. In the previous code, in the tx_empty() API implemented by the sh-sci driver, it is considered that the TX is empty if the hardware reports the TEND bit set and the number of data units in the FIFO is zero. According to the HW manual, the TEND bit has the following meaning: 0: Transmission is in the waiting state or in progress. 1: Transmission is completed. It has been noticed that when opening the serial device w/o using it and then switch to a power saving mode, the tx_empty() call in the uart_port_suspend() function fails, leading to the "Unable to drain transmitter" message being printed on the console. This is because the TEND=0 if nothing has been transmitted and the FIFOs are empty. As the TEND=0 has double meaning (waiting state, in progress) we can't determined the scenario described above. Add a software workaround for this. This sets a variable if any data has been sent on the serial console (when using PIO) or if the DMA callback has been called (meaning something has been transmitted). In the tx_empty() API the status of the DMA transaction is also checked and if it is completed or in progress the code falls back in checking the hardware registers instead of relying on the software variable. Fixes: 73a19e4c0301 ("serial: sh-sci: Add DMA support.") Cc: stable@vger.kernel.org Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Link: https://lore.kernel.org/r/20241125115856.513642-1-claudiu.beznea.uj@bp.renesas.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-04serial: 8250_pci: Share WCH IDs with parport_serial driverAndy Shevchenko
parport_serial driver uses subset of WCH IDs that are present in 8250_pci. Share them via pci_ids.h and switch parport_serial to use defined constants. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20241204031114.1029882-3-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-04serial: 8250_pci: Resolve WCH vendor ID ambiguityAndy Shevchenko
There are two sites of the same brand: wch.cn and wch-ic.com. They are property of the same company, but it appears that they managed to get two different PCI vendor IDs. Rename them accordingly using standard pattern, i.e. PCI_VENDOR_ID_... While at it, move to PCI_VDEVICE() in the ID tables. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20241204031114.1029882-2-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-04serial: mpc52xx: Fix typo in mpc52xx_uart.cZhu Jun
The word 'accoding' is wrong, so fix it. Signed-off-by: Zhu Jun <zhujun2@cmss.chinamobile.com> Link: https://lore.kernel.org/r/20241203095428.8559-1-zhujun2@cmss.chinamobile.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-04serial: 8250_port: Assign UPIO_UNKNOWN instead of its direct valueAndy Shevchenko
serial8250_init_port() assings 0xFF for the unset or unknown port IO type, use predefined constant for that instead. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Link: https://lore.kernel.org/r/20241125103305.1614986-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-04serial: sh-sci: Use plain struct copy in early_console_setup()Geert Uytterhoeven
Using memcpy() prevents the compiler from doing any checking on the types of the passed pointer parameters. Copy the structure using struct assignment instead, to increase type-safety. No change in generated code on all relevant architectures (arm/arm64/riscv/sh). Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Link: https://lore.kernel.org/r/e097e5c11afe5bd4c01135779c9a40e707ef6374.1733243287.git.geert+renesas@glider.be Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-04serial: altera_jtaguart: Use KBUILD_MODNAMETobias Klauser
There is no need to redefine the driver name. Use KBUILD_MODNAME and get rid of DRV_NAME altogether. Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/linux-serial/2024120337-unending-renewed-8e7e@gregkh/ Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Link: https://lore.kernel.org/r/20241203131727.9078-1-tklauser@distanz.ch Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-04serial: altera_jtaguart: Use device name when requesting IRQTobias Klauser
The request_irq name parameter should be the device name, not the driver name. This leads to more informative information in /proc/interrupts. Before this patch: $ cat /proc/interrupts ... 40: 123 0 GIC-0 72 Level altera_jtaguart After this patch: $ cat /proc/interrupts ... 40: 6 0 GIC-0 72 Level ff200100.fpga-juart0 Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Link: https://lore.kernel.org/r/20241203132556.14182-1-tklauser@distanz.ch Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-03module: Convert default symbol namespace to string literalMasahiro Yamada
Commit cdd30ebb1b9f ("module: Convert symbol namespace to string literal") only converted MODULE_IMPORT_NS() and EXPORT_SYMBOL_NS(), leaving DEFAULT_SYMBOL_NAMESPACE as a macro expansion. This commit converts DEFAULT_SYMBOL_NAMESPACE in the same way to avoid annoyance for the default namespace as well. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-12-02module: Convert symbol namespace to string literalPeter Zijlstra
Clean up the existing export namespace code along the same lines of commit 33def8498fdd ("treewide: Convert macro and uses of __section(foo) to __section("foo")") and for the same reason, it is not desired for the namespace argument to be a macro expansion itself. Scripted using git grep -l -e MODULE_IMPORT_NS -e EXPORT_SYMBOL_NS | while read file; do awk -i inplace ' /^#define EXPORT_SYMBOL_NS/ { gsub(/__stringify\(ns\)/, "ns"); print; next; } /^#define MODULE_IMPORT_NS/ { gsub(/__stringify\(ns\)/, "ns"); print; next; } /MODULE_IMPORT_NS/ { $0 = gensub(/MODULE_IMPORT_NS\(([^)]*)\)/, "MODULE_IMPORT_NS(\"\\1\")", "g"); } /EXPORT_SYMBOL_NS/ { if ($0 ~ /(EXPORT_SYMBOL_NS[^(]*)\(([^,]+),/) { if ($0 !~ /(EXPORT_SYMBOL_NS[^(]*)\(([^,]+), ([^)]+)\)/ && $0 !~ /(EXPORT_SYMBOL_NS[^(]*)\(\)/ && $0 !~ /^my/) { getline line; gsub(/[[:space:]]*\\$/, ""); gsub(/[[:space:]]/, "", line); $0 = $0 " " line; } $0 = gensub(/(EXPORT_SYMBOL_NS[^(]*)\(([^,]+), ([^)]+)\)/, "\\1(\\2, \"\\3\")", "g"); } } { print }' $file; done Requested-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://mail.google.com/mail/u/2/#inbox/FMfcgzQXKWgMmjdFwwdsfgxzKpVHWPlc Acked-by: Greg KH <gregkh@linuxfoundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-11-30Merge tag 'tty-6.13-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty / serial driver updates from Greg KH: "Here is a small set of tty and serial driver updates for 6.13-rc1. Nothing major at all this time, only some small changes: - few device tree binding updates - 8250_exar serial driver updates - imx serial driver updates - sprd_serial driver updates - other tiny serial driver updates, full details in the shortlog All of these have been in linux-next for a while with one reported issue, but that commit has now been reverted" * tag 'tty-6.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (37 commits) Revert "serial: sh-sci: Clean sci_ports[0] after at earlycon exit" serial: amba-pl011: fix build regression dt-bindings: serial: Add a new compatible string for ums9632 serial: sprd: Add support for sc9632 tty/serial/altera_uart: unwrap error log string tty/serial/altera_jtaguart: unwrap error log string serial: amba-pl011: Fix RX stall when DMA is used tty: ldsic: fix tty_ldisc_autoload sysctl's proc_handler serial: 8250_fintek: Add support for F81216E serial: sh-sci: Clean sci_ports[0] after at earlycon exit tty: atmel_serial: Fix typo retreives to retrieves tty: atmel_serial: Use devm_platform_ioremap_resource() serial: 8250: omap: Move pm_runtime_get_sync tty: serial: samsung: Add Exynos8895 compatible dt-bindings: serial: samsung: Add samsung,exynos8895-uart compatible serial: 8250_dw: Add Sophgo SG2044 quirk dt-bindings: serial: snps-dw-apb-uart: Add Sophgo SG2044 uarts dt-bindings: serial: snps,dw-apb-uart: merge duplicate compatible entry. altera_jtaguart: Use dev_err() to report error attaching IRQ altera_uart: Use dev_err() to report error attaching IRQ handler ...
2024-11-30Revert "serial: sh-sci: Clean sci_ports[0] after at earlycon exit"Greg Kroah-Hartman
This reverts commit 3791ea69a4858b81e0277f695ca40f5aae40f312. It was reported to cause boot-time issues, so revert it for now. Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Fixes: 3791ea69a485 ("serial: sh-sci: Clean sci_ports[0] after at earlycon exit") Cc: stable <stable@kernel.org> Cc: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
generated by cgit (git 2.34.1) at 2025-07-15 07:07:10 +0000