superrob1500
/
mirror-linux
mirror of https://github.com/torvalds/linux
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

serial: 8250: Add serial8250_handle_irq_locked() 

8250_port exports serial8250_handle_irq() to HW specific 8250 drivers.
It takes port's lock within but a HW specific 8250 driver may want to
take port's lock itself, do something, and then call the generic
handler in 8250_port but to do that, the caller has to release port's
lock for no good reason.

Introduce serial8250_handle_irq_locked() which a HW specific driver can
call while already holding port's lock.

As this is new export, put it straight into a namespace (where all 8250
exports should eventually be moved).

Tested-by: Bandal, Shankar <shankar.bandal@intel.com>
Tested-by: Murthy, Shanth <shanth.murthy@intel.com>
Cc: stable <stable@kernel.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://patch.msgid.link/20260203171049.4353-4-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
master
Ilpo Järvinen 2026-02-03 19:10:45 +02:00 committed by Greg Kroah-Hartman
parent 8002d6d6d0
commit 8324a54f60
2 changed files with 17 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

24
drivers/tty/serial/8250/8250_port.c
View File

@ -18,6 +18,7 @@
#include <linux/irq.h>
#include <linux/console.h>
#include <linux/gpio/consumer.h>
#include <linux/lockdep.h>
#include <linux/sysrq.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
@ -1782,20 +1783,16 @@ static bool handle_rx_dma(struct uart_8250_port *up, unsigned int iir)
}
/*
* This handles the interrupt from one port.
* Context: port's lock must be held by the caller.
*/
int serial8250_handle_irq(struct uart_port *port, unsigned int iir)
void serial8250_handle_irq_locked(struct uart_port *port, unsigned int iir)
{
struct uart_8250_port *up = up_to_u8250p(port);
struct tty_port *tport = &port->state->port;
bool skip_rx = false;
unsigned long flags;
u16 status;
if (iir & UART_IIR_NO_INT)
return 0;
uart_port_lock_irqsave(port, &flags);
lockdep_assert_held_once(&port->lock);
status = serial_lsr_in(up);
@ -1828,8 +1825,19 @@ int serial8250_handle_irq(struct uart_port *port, unsigned int iir)
else if (!up->dma->tx_running)
__stop_tx(up);
}
}
EXPORT_SYMBOL_NS_GPL(serial8250_handle_irq_locked, "SERIAL_8250");
uart_unlock_and_check_sysrq_irqrestore(port, flags);
/*
* This handles the interrupt from one port.
*/
int serial8250_handle_irq(struct uart_port *port, unsigned int iir)
{
if (iir & UART_IIR_NO_INT)
return 0;
guard(uart_port_lock_irqsave)(port);
serial8250_handle_irq_locked(port, iir);
return 1;
}

1
include/linux/serial_8250.h
View File

@ -195,6 +195,7 @@ void serial8250_do_set_mctrl(struct uart_port *port, unsigned int mctrl);
void serial8250_do_set_divisor(struct uart_port *port, unsigned int baud,
unsigned int quot);
int fsl8250_handle_irq(struct uart_port *port);
void serial8250_handle_irq_locked(struct uart_port *port, unsigned int iir);
int serial8250_handle_irq(struct uart_port *port, unsigned int iir);
u16 serial8250_rx_chars(struct uart_8250_port *up, u16 lsr);
void serial8250_read_char(struct uart_8250_port *up, u16 lsr);