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| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2024-03-01 22:45:15 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-03-02 22:06:20 +0100 |
| commit | 244a758b3d0550b008c304bfd522209927f512b4 (patch) | |
| tree | e2b8a3f8f86faf1bef156b6dba36359f9b4c0876 /drivers/tty | |
| parent | 2432f71c22d0543a86353ed0c505eda32d25af7c (diff) | |
| download | linux-244a758b3d0550b008c304bfd522209927f512b4.tar.gz linux-244a758b3d0550b008c304bfd522209927f512b4.tar.bz2 linux-244a758b3d0550b008c304bfd522209927f512b4.zip | |
serial: ar933x: 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/20240301215246.891055-3-bigeasy@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/serial/ar933x_uart.c | 18 |
1 files changed, 6 insertions, 12 deletions
diff --git a/drivers/tty/serial/ar933x_uart.c b/drivers/tty/serial/ar933x_uart.c index 8d09ace062e5..7790cbc57391 100644 --- a/drivers/tty/serial/ar933x_uart.c +++ b/drivers/tty/serial/ar933x_uart.c @@ -378,7 +378,7 @@ static void ar933x_uart_rx_chars(struct ar933x_uart_port *up) up->port.icount.rx++; ch = rdata & AR933X_UART_DATA_TX_RX_MASK; - if (uart_handle_sysrq_char(&up->port, ch)) + if (uart_prepare_sysrq_char(&up->port, ch)) continue; if ((up->port.ignore_status_mask & AR933X_DUMMY_STATUS_RD) == 0) @@ -468,7 +468,7 @@ static irqreturn_t ar933x_uart_interrupt(int irq, void *dev_id) ar933x_uart_tx_chars(up); } - uart_port_unlock(&up->port); + uart_unlock_and_check_sysrq(&up->port); return IRQ_HANDLED; } @@ -627,14 +627,10 @@ static void ar933x_uart_console_write(struct console *co, const char *s, unsigned int int_en; 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 @@ -654,9 +650,7 @@ static void ar933x_uart_console_write(struct console *co, const char *s, ar933x_uart_write(up, AR933X_UART_INT_REG, AR933X_UART_INT_ALLINTS); if (locked) - uart_port_unlock(&up->port); - - local_irq_restore(flags); + uart_port_unlock_irqrestore(&up->port, flags); } static int ar933x_uart_console_setup(struct console *co, char *options) |