From 92cc9d1d14e3ba8e82c99a4b4c90cce1db3c3fa9 Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Mon, 24 Jan 2022 08:14:25 +0100 Subject: [PATCH] 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 Link: https://lore.kernel.org/r/20220124071430.14907-7-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman --- drivers/tty/mxser.c | 24 +++++++++--------------- 1 file changed, 9 insertions(+), 15 deletions(-) diff --git a/drivers/tty/mxser.c b/drivers/tty/mxser.c index fbb796f..4ddc12a 100644 --- a/drivers/tty/mxser.c +++ b/drivers/tty/mxser.c @@ -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); } /* -- 2.7.4