diff options
| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2024-03-01 22:45:17 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-03-02 22:06:21 +0100 |
| commit | fb793b952a330e6c87aec98aeb300aaa5c2ac960 (patch) | |
| tree | 62f21ad8041c93c0b7c5d8dccda486cd2088a5f3 /drivers/tty | |
| parent | 8c1cbc5a2b7b4980b05bd0587c458c8cd89b59da (diff) | |
| download | linux-fb793b952a330e6c87aec98aeb300aaa5c2ac960.tar.gz | |
serial: meson: 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.
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: Jerome Brunet <jbrunet@baylibre.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-amlogic@lists.infradead.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20240301215246.891055-5-bigeasy@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/serial/meson_uart.c | 22 |
1 files changed, 8 insertions, 14 deletions
diff --git a/drivers/tty/serial/meson_uart.c b/drivers/tty/serial/meson_uart.c index 8395688f5ee92..6feac459c0cf4 100644 --- a/drivers/tty/serial/meson_uart.c +++ b/drivers/tty/serial/meson_uart.c @@ -220,7 +220,7 @@ static void meson_receive_chars(struct uart_port *port) continue; } - if (uart_handle_sysrq_char(port, ch)) + if (uart_prepare_sysrq_char(port, ch)) continue; if ((status & port->ignore_status_mask) == 0) @@ -248,7 +248,7 @@ static irqreturn_t meson_uart_interrupt(int irq, void *dev_id) meson_uart_start_tx(port); } - uart_port_unlock(port); + uart_unlock_and_check_sysrq(port); return IRQ_HANDLED; } @@ -556,18 +556,13 @@ static void meson_serial_port_write(struct uart_port *port, const char *s, u_int count) { unsigned long flags; - int locked; + int locked = 1; u32 val, tmp; - local_irq_save(flags); - 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); val = readl(port->membase + AML_UART_CONTROL); tmp = val & ~(AML_UART_TX_INT_EN | AML_UART_RX_INT_EN); @@ -577,8 +572,7 @@ static void meson_serial_port_write(struct uart_port *port, const char *s, writel(val, port->membase + AML_UART_CONTROL); if (locked) - uart_port_unlock(port); - local_irq_restore(flags); + uart_port_unlock_irqrestore(port, flags); } static void meson_serial_console_write(struct console *co, const char *s, |