diff options
Diffstat (limited to 'debian/patches-rt/0008-serial-sunplus-Use-uart_prepare_sysrq_char.patch')
| -rw-r--r-- | debian/patches-rt/0008-serial-sunplus-Use-uart_prepare_sysrq_char.patch | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/debian/patches-rt/0008-serial-sunplus-Use-uart_prepare_sysrq_char.patch b/debian/patches-rt/0008-serial-sunplus-Use-uart_prepare_sysrq_char.patch new file mode 100644 index 000000000..fc7a5b725 --- /dev/null +++ b/debian/patches-rt/0008-serial-sunplus-Use-uart_prepare_sysrq_char.patch @@ -0,0 +1,67 @@ +From: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +Date: Fri, 1 Mar 2024 22:45:21 +0100 +Subject: [PATCH 08/18] serial: sunplus: Use uart_prepare_sysrq_char(). +Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.8/older/patches-6.8.2-rt11.tar.xz + +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. + +Cc: Hammer Hsieh <hammerh0314@gmail.com> +Link: https://lore.kernel.org/r/20240301215246.891055-9-bigeasy@linutronix.de +Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +--- + drivers/tty/serial/sunplus-uart.c | 18 ++++++------------ + 1 file changed, 6 insertions(+), 12 deletions(-) + +--- a/drivers/tty/serial/sunplus-uart.c ++++ b/drivers/tty/serial/sunplus-uart.c +@@ -260,7 +260,7 @@ static void receive_chars(struct uart_po + if (port->ignore_status_mask & SUP_DUMMY_READ) + goto ignore_char; + +- if (uart_handle_sysrq_char(port, ch)) ++ if (uart_prepare_sysrq_char(port, ch)) + goto ignore_char; + + uart_insert_char(port, lsr, SUP_UART_LSR_OE, ch, flag); +@@ -287,7 +287,7 @@ static irqreturn_t sunplus_uart_irq(int + if (isc & SUP_UART_ISC_TX) + transmit_chars(port); + +- uart_port_unlock(port); ++ uart_unlock_and_check_sysrq(port); + + return IRQ_HANDLED; + } +@@ -512,22 +512,16 @@ static void sunplus_console_write(struct + unsigned long flags; + int locked = 1; + +- local_irq_save(flags); +- +- if (sunplus_console_ports[co->index]->port.sysrq) +- locked = 0; +- else if (oops_in_progress) +- locked = uart_port_trylock(&sunplus_console_ports[co->index]->port); ++ if (oops_in_progress) ++ locked = uart_port_trylock_irqsave(&sunplus_console_ports[co->index]->port, &flags); + else +- uart_port_lock(&sunplus_console_ports[co->index]->port); ++ uart_port_lock_irqsave(&sunplus_console_ports[co->index]->port, &flags); + + uart_console_write(&sunplus_console_ports[co->index]->port, s, count, + sunplus_uart_console_putchar); + + if (locked) +- uart_port_unlock(&sunplus_console_ports[co->index]->port); +- +- local_irq_restore(flags); ++ uart_port_unlock_irqrestore(&sunplus_console_ports[co->index]->port, flags); + } + + static int __init sunplus_console_setup(struct console *co, char *options) |