diff options
| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2024-03-02 00:45:25 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-03-03 00:06:21 +0300 |
| commit | 32c694ec3efc2b7cdf921da50371297ba70e7d50 (patch) | |
| tree | bce005423c4c46b9543ae711845df45ae829f91a /drivers/tty | |
| parent | bb0b3142055d006431ac05663d38c069602b5967 (diff) | |
| download | linux-32c694ec3efc2b7cdf921da50371297ba70e7d50.tar.xz | |
serial: sifive: Use uart_prepare_sysrq_char() to handle sysrq.
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.
Handle sysrq requests sysrq once the port lock is dropped.
Remove the special case in the console write routine an always use the
complete locking function.
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: linux-riscv@lists.infradead.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20240301215246.891055-13-bigeasy@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/serial/sifive.c | 17 |
1 files changed, 7 insertions, 10 deletions
diff --git a/drivers/tty/serial/sifive.c b/drivers/tty/serial/sifive.c index a4cc569a78a2..0670fd9f8496 100644 --- a/drivers/tty/serial/sifive.c +++ b/drivers/tty/serial/sifive.c @@ -412,7 +412,8 @@ static void __ssp_receive_chars(struct sifive_serial_port *ssp) break; ssp->port.icount.rx++; - uart_insert_char(&ssp->port, 0, 0, ch, TTY_NORMAL); + if (!uart_prepare_sysrq_char(&ssp->port, ch)) + uart_insert_char(&ssp->port, 0, 0, ch, TTY_NORMAL); } tty_flip_buffer_push(&ssp->port.state->port); @@ -534,7 +535,7 @@ static irqreturn_t sifive_serial_irq(int irq, void *dev_id) if (ip & SIFIVE_SERIAL_IP_TXWM_MASK) __ssp_transmit_chars(ssp); - uart_port_unlock(&ssp->port); + uart_unlock_and_check_sysrq(&ssp->port); return IRQ_HANDLED; } @@ -791,13 +792,10 @@ static void sifive_serial_console_write(struct console *co, const char *s, if (!ssp) return; - local_irq_save(flags); - if (ssp->port.sysrq) - locked = 0; - else if (oops_in_progress) - locked = uart_port_trylock(&ssp->port); + if (oops_in_progress) + locked = uart_port_trylock_irqsave(&ssp->port, &flags); else - uart_port_lock(&ssp->port); + uart_port_lock_irqsave(&ssp->port, &flags); ier = __ssp_readl(ssp, SIFIVE_SERIAL_IE_OFFS); __ssp_writel(0, SIFIVE_SERIAL_IE_OFFS, ssp); @@ -807,8 +805,7 @@ static void sifive_serial_console_write(struct console *co, const char *s, __ssp_writel(ier, SIFIVE_SERIAL_IE_OFFS, ssp); if (locked) - uart_port_unlock(&ssp->port); - local_irq_restore(flags); + uart_port_unlock_irqrestore(&ssp->port, flags); } static int sifive_serial_console_setup(struct console *co, char *options) |