mxser: use tty_port xmit_buf helpers

For the mxser driver to use kfifo, use tty_port_alloc_xmit_buf() and
tty_port_free_xmit_buf() helpers in activate/shutdown, respectively.

As these calls have to be done in a non-atomic context, we have to move
them outside spinlock and make sure irq is really stopped after we write
to the ISR register.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20220124071430.14907-7-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jiri Slaby 2022-01-24 08:14:25 +01:00 committed by Greg Kroah-Hartman
parent cd3a4907ee
commit 92cc9d1d14
1 changed files with 9 additions and 15 deletions

View File

@ -742,13 +742,12 @@ static void mxser_disable_and_clear_FIFO(struct mxser_port *info)
static int mxser_activate(struct tty_port *port, struct tty_struct *tty)
{
struct mxser_port *info = container_of(port, struct mxser_port, port);
unsigned long page;
unsigned long flags;
int ret;
page = __get_free_page(GFP_KERNEL);
if (!page)
return -ENOMEM;
ret = tty_port_alloc_xmit_buf(port);
if (ret < 0)
return ret;
spin_lock_irqsave(&info->slock, flags);
@ -758,7 +757,6 @@ static int mxser_activate(struct tty_port *port, struct tty_struct *tty)
ret = 0;
goto err_free_xmit;
}
info->port.xmit_buf = (unsigned char *) page;
/*
* Clear the FIFO buffers and disable them
@ -825,8 +823,7 @@ static int mxser_activate(struct tty_port *port, struct tty_struct *tty)
return 0;
err_free_xmit:
free_page(page);
info->port.xmit_buf = NULL;
tty_port_free_xmit_buf(port);
return ret;
}
@ -862,14 +859,6 @@ static void mxser_shutdown_port(struct tty_port *port)
*/
wake_up_interruptible(&info->port.delta_msr_wait);
/*
* Free the xmit buffer, if necessary
*/
if (info->port.xmit_buf) {
free_page((unsigned long) info->port.xmit_buf);
info->port.xmit_buf = NULL;
}
info->IER = 0;
outb(0x00, info->ioaddr + UART_IER);
@ -884,6 +873,11 @@ static void mxser_shutdown_port(struct tty_port *port)
mxser_must_no_sw_flow_control(info->ioaddr);
spin_unlock_irqrestore(&info->slock, flags);
/* make sure ISR is not running while we free the buffer */
synchronize_irq(info->board->irq);
tty_port_free_xmit_buf(port);
}
/*