kernel/drivers/tty/serial/ar933x_uart.c, branch linux-6.9.y

serial: ar933x: Use uart_prepare_sysrq_char().

2024-03-02T21:06:20Z

The port lock is a spinlock_t which is becomes a sleeping lock on PREEMPT_RT. The driver splits the locking function into two parts: local_irq_save() and uart_port_lock() and this breaks PREEMPT_RT. Delay handling sysrq until port lock is dropped. Remove the special case in the console write routine an always use the complete locking function. Signed-off-by: Sebastian Andrzej Siewior Link: https://lore.kernel.org/r/20240301215246.891055-3-bigeasy@linutronix.de Signed-off-by: Greg Kroah-Hartman

serial: ar933x: Convert to platform remove callback returning void

2023-11-23T19:12:30Z

The .remove() callback for a platform driver returns an int which makes many driver authors wrongly assume it's possible to do error handling by returning an error code. However the value returned is ignored (apart from emitting a warning) and this typically results in resource leaks. To improve here there is a quest to make the remove callback return void. In the first step of this quest all drivers are converted to .remove_new(), which already returns void. Eventually after all drivers are converted, .remove_new() will be renamed to .remove(). Trivially convert this driver from always returning zero in the remove callback to the void returning variant. Signed-off-by: Uwe Kleine-König Link: https://lore.kernel.org/r/20231110152927.70601-8-u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman

serial: ar933x: Use port lock wrappers

2023-09-18T09:18:10Z

When a serial port is used for kernel console output, then all modifications to the UART registers which are done from other contexts, e.g. getty, termios, are interference points for the kernel console. So far this has been ignored and the printk output is based on the principle of hope. The rework of the console infrastructure which aims to support threaded and atomic consoles, requires to mark sections which modify the UART registers as unsafe. This allows the atomic write function to make informed decisions and eventually to restore operational state. It also allows to prevent the regular UART code from modifying UART registers while printk output is in progress. All modifications of UART registers are guarded by the UART port lock, which provides an obvious synchronization point with the console infrastructure. To avoid adding this functionality to all UART drivers, wrap the spin_[un]lock*() invocations for uart_port::lock into helper functions which just contain the spin_[un]lock*() invocations for now. In a subsequent step these helpers will gain the console synchronization mechanisms. Converted with coccinelle. No functional change. Signed-off-by: Thomas Gleixner Signed-off-by: John Ogness Link: https://lore.kernel.org/r/20230914183831.587273-20-john.ogness@linutronix.de Signed-off-by: Greg Kroah-Hartman

serial: ar933x: Use devm_platform_get_and_ioremap_resource()

2023-07-25T18:25:52Z

Convert platform_get_resource(), devm_ioremap_resource() to a single call to devm_platform_get_and_ioremap_resource(), as this is exactly what this function does. Signed-off-by: Yangtao Li Link: https://lore.kernel.org/r/20230712062853.11007-1-frank.li@vivo.com Signed-off-by: Greg Kroah-Hartman

serial: ar933x: Use uart_xmit_advance()

2022-11-03T02:35:41Z

Take advantage of the new uart_xmit_advance() helper. Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20221019091151.6692-10-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman

serial: ar933x: Deassert Transmit Enable on ->rs485_config()

2022-09-22T14:43:05Z

The ar933x_uart driver neglects to deassert Transmit Enable when ->rs485_config() is invoked. Fix it. Fixes: 9be1064fe524 ("serial: ar933x_uart: add RS485 support") Cc: stable@vger.kernel.org # v5.7+ Cc: Daniel Golle Reviewed-by: Ilpo Järvinen Signed-off-by: Lukas Wunner Link: https://lore.kernel.org/r/5b36af26e57553f084334666e7d24c7fd131a01e.1662887231.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman

serial: Make ->set_termios() old ktermios const

2022-08-30T12:22:35Z

There should be no reason to adjust old ktermios which is going to get discarded anyway. Reviewed-by: Andy Shevchenko Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20220816115739.10928-7-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman

serial: ar933x: Remove superfluous code in ar933x_config_rs485()

2022-07-14T14:34:23Z

In ar933x_config_rs485() the check for the RTS GPIO is not needed since in case the GPIO is not available at driver init ar933x_no_rs485 is assigned to port->rs485_supported and this function is never called. So remove the check. Also in uart_set_rs485_config() the serial core already assigns the passed serial_rs485 struct to the uart port. So remove the assignment in the drivers rs485_config() function to avoid redundancy. Signed-off-by: Lino Sanfilippo Link: https://lore.kernel.org/r/20220710164442.2958979-3-LinoSanfilippo@gmx.de Signed-off-by: Greg Kroah-Hartman

serial: ar933x: Fix check for RS485 support

2022-07-14T14:34:23Z

RS485 is not possible without an RTS GPIO regardless of whether RS485 is enabled at boot time or not. So correct the concerning check in the probe() function. Fixes: e849145e1fdd ("serial: ar933x: Fill in rs485_supported") Signed-off-by: Lino Sanfilippo Link: https://lore.kernel.org/r/20220710164442.2958979-2-LinoSanfilippo@gmx.de Signed-off-by: Greg Kroah-Hartman

serial: Embed rs485_supported to uart_port

2022-07-08T13:14:09Z

Embed rs485_supported to uart_port to allow serial core to tweak it as needed. Reviewed-by: Lino Sanfilippo Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20220704094515.6831-2-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman