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serial: sifive: lock port in startup()/shutdown() callbacks

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commit e1ca3ff28a upstream.

startup()/shutdown() callbacks access SIFIVE_SERIAL_IE_OFFS.
The register is also accessed from write() callback.

If console were printing and startup()/shutdown() callback
gets called, its access to the register could be overwritten.

Add port->lock to startup()/shutdown() callbacks to make sure
their access to SIFIVE_SERIAL_IE_OFFS is synchronized against
write() callback.

Fixes: 45c054d081 ("tty: serial: add driver for the SiFive UART")
Signed-off-by: Ryo Takakura <ryotkkr98@gmail.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: stable@vger.kernel.org
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Rule: add
Link: https://lore.kernel.org/stable/20250330003522.386632-1-ryotkkr98%40gmail.com
Link: https://lore.kernel.org/r/20250412001847.183221-1-ryotkkr98@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Ryo Takakura
2025-04-12 09:18:47 +09:00
committed by Greg Kroah-Hartman
parent 116c7d35b8
commit b59c7fefde
1 changed files with 6 additions and 0 deletions
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drivers/tty/serial/sifive.c
+6
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@@ -595,8 +595,11 @@ static void sifive_serial_break_ctl(struct uart_port *port, int break_state)
static int sifive_serial_startup(struct uart_port *port)
{
struct sifive_serial_port *ssp = port_to_sifive_serial_port(port);
unsigned long flags;
uart_port_lock_irqsave(&ssp->port, &flags);
__ssp_enable_rxwm(ssp);
uart_port_unlock_irqrestore(&ssp->port, flags);
return 0;
}
@@ -604,9 +607,12 @@ static int sifive_serial_startup(struct uart_port *port)
static void sifive_serial_shutdown(struct uart_port *port)
{
struct sifive_serial_port *ssp = port_to_sifive_serial_port(port);
unsigned long flags;
uart_port_lock_irqsave(&ssp->port, &flags);
__ssp_disable_rxwm(ssp);
__ssp_disable_txwm(ssp);
uart_port_unlock_irqrestore(&ssp->port, flags);
}
/**