[PATCH 03/19] mxser: keep only !tty test in ISR
From: Jiri Slaby <hidden>
Date: 2021-11-18 07:31:48
Also in:
lkml
Subsystem:
moxa smartio/industio/intellio serial card, the rest, tty layer and serial drivers · Maintainers:
Jiri Slaby, Linus Torvalds, Greg Kroah-Hartman
The others are superfluous with tty refcounting in place now. And they are racy in fact: * tty_port_initialized() reports false for a small moment after interrupts are enabled. * closing is 1 while the port is still alive. The queues are flushed later during close anyway. So there is no need for this special handling. Actually, the ISR should not flush the queues. It should behave as every other driver, just queue the chars into tty buffer and go on. But this will be changed later. There is still a lot code depending on having tty in ISR (and not only tty_port). Signed-off-by: Jiri Slaby <redacted> --- drivers/tty/mxser.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/drivers/tty/mxser.c b/drivers/tty/mxser.c
index e9248d39879c..c8a56b0d900d 100644
--- a/drivers/tty/mxser.c
+++ b/drivers/tty/mxser.c@@ -262,7 +262,6 @@ struct mxser_port { unsigned int xmit_head; unsigned int xmit_tail; unsigned int xmit_cnt; - int closing; spinlock_t slock; };
@@ -903,7 +902,6 @@ static void mxser_close(struct tty_struct *tty, struct file *filp) return; if (tty_port_close_start(port, tty, filp) == 0) return; - info->closing = 1; mutex_lock(&port->mutex); mxser_stop_rx(info); mxser_flush_buffer(tty);
@@ -912,7 +910,6 @@ static void mxser_close(struct tty_struct *tty, struct file *filp) mxser_shutdown_port(port); tty_port_set_initialized(port, 0); mutex_unlock(&port->mutex); - info->closing = 0; /* Right now the tty_port set is done outside of the close_end helper as we don't yet have everyone using refcounts */ tty_port_close_end(port, tty);
@@ -1668,7 +1665,7 @@ static bool mxser_port_isr(struct mxser_port *port) iir &= MOXA_MUST_IIR_MASK; tty = tty_port_tty_get(&port->port); - if (!tty || port->closing || !tty_port_initialized(&port->port)) { + if (!tty) { status = inb(port->ioaddr + UART_LSR); outb(port->FCR | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT, port->ioaddr + UART_FCR);
--
2.33.1