diff options
Diffstat (limited to 'debian/patches-rt/0007-serial-pxa-Use-uart_prepare_sysrq_char.patch')
| -rw-r--r-- | debian/patches-rt/0007-serial-pxa-Use-uart_prepare_sysrq_char.patch | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/debian/patches-rt/0007-serial-pxa-Use-uart_prepare_sysrq_char.patch b/debian/patches-rt/0007-serial-pxa-Use-uart_prepare_sysrq_char.patch new file mode 100644 index 000000000..ae76e2587 --- /dev/null +++ b/debian/patches-rt/0007-serial-pxa-Use-uart_prepare_sysrq_char.patch @@ -0,0 +1,68 @@ +From: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +Date: Fri, 1 Mar 2024 22:45:20 +0100 +Subject: [PATCH 07/18] serial: pxa: 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. + +Link: https://lore.kernel.org/r/20240301215246.891055-8-bigeasy@linutronix.de +Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +--- + drivers/tty/serial/pxa.c | 17 ++++++----------- + 1 file changed, 6 insertions(+), 11 deletions(-) + +--- a/drivers/tty/serial/pxa.c ++++ b/drivers/tty/serial/pxa.c +@@ -151,7 +151,7 @@ static inline void receive_chars(struct + flag = TTY_FRAME; + } + +- if (uart_handle_sysrq_char(&up->port, ch)) ++ if (uart_prepare_sysrq_char(&up->port, ch)) + goto ignore_char; + + uart_insert_char(&up->port, *status, UART_LSR_OE, ch, flag); +@@ -232,7 +232,7 @@ static inline irqreturn_t serial_pxa_irq + check_modem_status(up); + if (lsr & UART_LSR_THRE) + transmit_chars(up); +- uart_port_unlock(&up->port); ++ uart_unlock_and_check_sysrq(&up->port); + return IRQ_HANDLED; + } + +@@ -604,13 +604,10 @@ serial_pxa_console_write(struct console + int locked = 1; + + clk_enable(up->clk); +- local_irq_save(flags); +- if (up->port.sysrq) +- locked = 0; +- else if (oops_in_progress) +- locked = uart_port_trylock(&up->port); ++ if (oops_in_progress) ++ locked = uart_port_trylock_irqsave(&up->port, &flags); + else +- uart_port_lock(&up->port); ++ uart_port_lock_irqsave(&up->port, &flags); + + /* + * First save the IER then disable the interrupts +@@ -628,10 +625,8 @@ serial_pxa_console_write(struct console + serial_out(up, UART_IER, ier); + + if (locked) +- uart_port_unlock(&up->port); +- local_irq_restore(flags); ++ uart_port_unlock_irqrestore(&up->port, flags); + clk_disable(up->clk); +- + } + + #ifdef CONFIG_CONSOLE_POLL |