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

serial: sifive: Use uart_prepare_sysrq_char() to handle sysrq.

2024-03-02T21:06:21Z

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. Handle sysrq requests sysrq once the port lock is dropped. Remove the special case in the console write routine an always use the complete locking function. Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: linux-riscv@lists.infradead.org Signed-off-by: Sebastian Andrzej Siewior Link: https://lore.kernel.org/r/20240301215246.891055-13-bigeasy@linutronix.de Signed-off-by: Greg Kroah-Hartman

serial: sifive: Declare PM operations as static

2023-11-23T19:31:18Z

They are only used within this file, so they should have static linkage. Signed-off-by: Samuel Holland Link: https://lore.kernel.org/r/20231113023122.1185407-1-samuel.holland@sifive.com Signed-off-by: Greg Kroah-Hartman

serial: sifive: Convert to platform remove callback returning void

2023-11-23T19:12:34Z

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 Reviewed-by: Samuel Holland Link: https://lore.kernel.org/r/20231110152927.70601-40-u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman

serial: sifive: Use port lock wrappers

2023-09-18T09:18:15Z

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/20230914183831.587273-62-john.ogness@linutronix.de Signed-off-by: Greg Kroah-Hartman

serial: sifive: Add suspend and resume operations

2023-08-22T13:29:10Z

If the Sifive Uart is not used as the wake up source, suspend the uart before the system enter the suspend state to prevent it woken up by unexpected uart interrupt. Resume the uart once the system woken up. Signed-off-by: Nick Hu Reviewed-by: Ben Dooks Link: https://lore.kernel.org/r/20230815090216.2575971-1-nick.hu@sifive.com Signed-off-by: Greg Kroah-Hartman

serial: sifive: Remove redundant of_match_ptr()

2023-08-09T12:15:25Z

The driver depends on CONFIG_OF, it is not necessary to use of_match_ptr() here. Signed-off-by: Ruan Jinjie Link: https://lore.kernel.org/r/20230809085541.2969654-1-ruanjinjie@huawei.com Signed-off-by: Greg Kroah-Hartman

Merge 6.5-rc4 into tty-next

2023-07-31T07:39:56Z

We need the serial/tty fixes in here as well for testing and future development. Signed-off-by: Greg Kroah-Hartman

serial: sifive: Fix sifive_serial_console_setup() section

2023-07-25T18:30:02Z

This function is called indirectly from the platform driver probe function. Even if the driver is built in, it may be probed after free_initmem() due to deferral or unbinding/binding via sysfs. Thus the function cannot be marked as __init. Fixes: 45c054d0815b ("tty: serial: add driver for the SiFive UART") Cc: stable Signed-off-by: Samuel Holland Link: https://lore.kernel.org/r/20230624060159.3401369-1-samuel.holland@sifive.com Signed-off-by: Greg Kroah-Hartman

serial: sifive: Use devm_platform_get_and_ioremap_resource()

2023-07-25T18:26:07Z

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/20230712062853.11007-13-frank.li@vivo.com Signed-off-by: Greg Kroah-Hartman

serial: drivers: switch ch and flag to u8

2023-07-25T17:21:04Z

Now that the serial layer explicitly expects 'u8' for flags and characters, propagate this type to drivers' (RX) routines. Note that amba-pl011's, clps711x's and st-asc's 'ch' are left unchanged because 'ch' contains not only a character, but whole status. Signed-off-by: Jiri Slaby (SUSE) Cc: Tobias Klauser Cc: Russell King Cc: Vineet Gupta Cc: Richard Genoud Cc: Nicolas Ferre Cc: Alexandre Belloni Cc: Claudiu Beznea Cc: Alexander Shiyan Cc: Baruch Siach Cc: "Maciej W. Rozycki" Cc: Taichi Sugaya Cc: Takao Orito Cc: Shawn Guo Cc: Sascha Hauer Cc: Pengutronix Kernel Team Cc: Fabio Estevam Cc: NXP Linux Team Cc: Kevin Cernekee Cc: Krzysztof Kozlowski Cc: Alim Akhtar Cc: Laxman Dewangan Cc: Thierry Reding Cc: Jonathan Hunter Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: Orson Zhai Cc: Baolin Wang Cc: Chunyan Zhang Cc: Patrice Chotard Cc: Maxime Coquelin Cc: Alexandre Torgue Cc: Hammer Hsieh Acked-by: Richard GENOUD Acked-by: Tobias Klauser Acked-by: Thierry Reding Acked-by: Maciej W. Rozycki Link: https://lore.kernel.org/r/20230712081811.29004-11-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman