diff options
| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2024-03-02 00:45:24 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-03-03 00:06:21 +0300 |
| commit | bb0b3142055d006431ac05663d38c069602b5967 (patch) | |
| tree | 2c809b6a30b11a34b4e446c2cba45f7fb765305c /drivers/tty/serial | |
| parent | 2af521486761f6f40ff00faa0cd3d52465dfd461 (diff) | |
| download | linux-bb0b3142055d006431ac05663d38c069602b5967.tar.xz | |
serial: rda: 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: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-unisoc@lists.infradead.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20240301215246.891055-12-bigeasy@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/serial')
| -rw-r--r-- | drivers/tty/serial/rda-uart.c | 28 |
1 files changed, 10 insertions, 18 deletions
diff --git a/drivers/tty/serial/rda-uart.c b/drivers/tty/serial/rda-uart.c index 13deb355cf1b..82def9b8632a 100644 --- a/drivers/tty/serial/rda-uart.c +++ b/drivers/tty/serial/rda-uart.c @@ -394,7 +394,8 @@ static void rda_uart_receive_chars(struct uart_port *port) val &= 0xff; port->icount.rx++; - tty_insert_flip_char(&port->state->port, val, flag); + if (!uart_prepare_sysrq_char(port, val)) + tty_insert_flip_char(&port->state->port, val, flag); status = rda_uart_read(port, RDA_UART_STATUS); } @@ -405,10 +406,9 @@ static void rda_uart_receive_chars(struct uart_port *port) static irqreturn_t rda_interrupt(int irq, void *dev_id) { struct uart_port *port = dev_id; - unsigned long flags; u32 val, irq_mask; - uart_port_lock_irqsave(port, &flags); + uart_port_lock(port); /* Clear IRQ cause */ val = rda_uart_read(port, RDA_UART_IRQ_CAUSE); @@ -425,7 +425,7 @@ static irqreturn_t rda_interrupt(int irq, void *dev_id) rda_uart_send_chars(port); } - uart_port_unlock_irqrestore(port, flags); + uart_unlock_and_check_sysrq(port); return IRQ_HANDLED; } @@ -590,18 +590,12 @@ static void rda_uart_port_write(struct uart_port *port, const char *s, { u32 old_irq_mask; unsigned long flags; - int locked; - - local_irq_save(flags); + int locked = 1; - if (port->sysrq) { - locked = 0; - } else if (oops_in_progress) { - locked = uart_port_trylock(port); - } else { - uart_port_lock(port); - locked = 1; - } + if (oops_in_progress) + locked = uart_port_trylock_irqsave(port, &flags); + else + uart_port_lock_irqsave(port, &flags); old_irq_mask = rda_uart_read(port, RDA_UART_IRQ_MASK); rda_uart_write(port, 0, RDA_UART_IRQ_MASK); @@ -615,9 +609,7 @@ static void rda_uart_port_write(struct uart_port *port, const char *s, rda_uart_write(port, old_irq_mask, RDA_UART_IRQ_MASK); if (locked) - uart_port_unlock(port); - - local_irq_restore(flags); + uart_port_unlock_irqrestore(port, flags); } static void rda_uart_console_write(struct console *co, const char *s, |