diff options
Diffstat (limited to 'debian/patches-rt/0006-serial-omap-Use-uart_prepare_sysrq_char.patch')
| -rw-r--r-- | debian/patches-rt/0006-serial-omap-Use-uart_prepare_sysrq_char.patch | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/debian/patches-rt/0006-serial-omap-Use-uart_prepare_sysrq_char.patch b/debian/patches-rt/0006-serial-omap-Use-uart_prepare_sysrq_char.patch new file mode 100644 index 000000000..58fe8b132 --- /dev/null +++ b/debian/patches-rt/0006-serial-omap-Use-uart_prepare_sysrq_char.patch @@ -0,0 +1,66 @@ +From: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +Date: Fri, 1 Mar 2024 22:45:19 +0100 +Subject: [PATCH 06/18] serial: omap: 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/20240301215246.891055-7-bigeasy@linutronix.de +Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +--- + drivers/tty/serial/omap-serial.c | 16 ++++++---------- + 1 file changed, 6 insertions(+), 10 deletions(-) + +--- a/drivers/tty/serial/omap-serial.c ++++ b/drivers/tty/serial/omap-serial.c +@@ -508,7 +508,7 @@ static void serial_omap_rdi(struct uart_ + + up->port.icount.rx++; + +- if (uart_handle_sysrq_char(&up->port, ch)) ++ if (uart_prepare_sysrq_char(&up->port, ch)) + return; + + uart_insert_char(&up->port, lsr, UART_LSR_OE, ch, TTY_NORMAL); +@@ -563,7 +563,7 @@ static irqreturn_t serial_omap_irq(int i + } + } while (max_count--); + +- uart_port_unlock(&up->port); ++ uart_unlock_and_check_sysrq(&up->port); + + tty_flip_buffer_push(&up->port.state->port); + +@@ -1212,13 +1212,10 @@ serial_omap_console_write(struct console + unsigned int ier; + int locked = 1; + +- 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 +@@ -1245,8 +1242,7 @@ serial_omap_console_write(struct console + check_modem_status(up); + + if (locked) +- uart_port_unlock(&up->port); +- local_irq_restore(flags); ++ uart_port_unlock_irqrestore(&up->port, flags); + } + + static int __init |