diff options
| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2024-03-01 22:45:31 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-03-02 22:06:22 +0100 |
| commit | d47dd323bf959dbf5f3e7f83373c8ed5f3bec9c0 (patch) | |
| tree | 6816020b0001ace93a08c4a691f56bb3eb701aed /drivers/tty | |
| parent | 06d28ca0c66cbb4e3716454f365f9cbb1e57a681 (diff) | |
serial: pch: Use uart_prepare_sysrq_char().
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 <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20240301215246.891055-19-bigeasy@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/serial/pch_uart.c | 24 |
1 files changed, 9 insertions, 15 deletions
diff --git a/drivers/tty/serial/pch_uart.c b/drivers/tty/serial/pch_uart.c index 92cb3c623cc3..89257cddf540 100644 --- a/drivers/tty/serial/pch_uart.c +++ b/drivers/tty/serial/pch_uart.c @@ -564,7 +564,7 @@ static int pch_uart_hal_read(struct eg20t_port *priv, unsigned char *buf, if (uart_handle_break(port)) continue; } - if (uart_handle_sysrq_char(port, rbr)) + if (uart_prepare_sysrq_char(port, rbr)) continue; buf[i++] = rbr; @@ -1070,7 +1070,7 @@ static irqreturn_t pch_uart_interrupt(int irq, void *dev_id) handled |= (unsigned int)ret; } - uart_port_unlock(&priv->port); + uart_unlock_and_check_sysrq(&priv->port); return IRQ_RETVAL(handled); } @@ -1550,22 +1550,17 @@ pch_console_write(struct console *co, const char *s, unsigned int count) { struct eg20t_port *priv; unsigned long flags; - int port_locked = 1; + int locked = 1; u8 ier; priv = pch_uart_ports[co->index]; touch_nmi_watchdog(); - local_irq_save(flags); - if (priv->port.sysrq) { - /* serial8250_handle_port() already took the port lock */ - port_locked = 0; - } else if (oops_in_progress) { - port_locked = uart_port_trylock(&priv->port); - } else { - uart_port_lock(&priv->port); - } + if (oops_in_progress) + locked = uart_port_trylock_irqsave(&priv->port, &flags); + else + uart_port_lock_irqsave(&priv->port, &flags); /* * First save the IER then disable the interrupts @@ -1583,9 +1578,8 @@ pch_console_write(struct console *co, const char *s, unsigned int count) wait_for_xmitr(priv, UART_LSR_BOTH_EMPTY); iowrite8(ier, priv->membase + UART_IER); - if (port_locked) - uart_port_unlock(&priv->port); - local_irq_restore(flags); + if (locked) + uart_port_unlock_irqrestore(&priv->port, flags); } static int __init pch_console_setup(struct console *co, char *options) |