tty/serial: lay the foundations for the next set of reworks
- Stop drivers calling their own flush method indirectly, it obfuscates code
and it will change soon anyway
- A few more lock_kernel paths temporarily needed in some driver internal
waiting code
- Remove private put_char method that does a write call for one char - we
have that anyway
- Most but not yet all of the termios copy under lock fixing (some has other
dependencies to follow)
- Note a few locking bugs in drivers found in the process
- Kill remaining [ab]users of TIOCG/SSOFTCAR in the driver, these must go to
fix the termios locking
Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/char/mxser.c b/drivers/char/mxser.c
index 00cf09a..28f6356 100644
--- a/drivers/char/mxser.c
+++ b/drivers/char/mxser.c
@@ -927,6 +927,27 @@
return 0;
}
+static void mxser_flush_buffer(struct tty_struct *tty)
+{
+ struct mxser_port *info = tty->driver_data;
+ char fcr;
+ unsigned long flags;
+
+
+ spin_lock_irqsave(&info->slock, flags);
+ info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
+
+ fcr = inb(info->ioaddr + UART_FCR);
+ outb((fcr | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT),
+ info->ioaddr + UART_FCR);
+ outb(fcr, info->ioaddr + UART_FCR);
+
+ spin_unlock_irqrestore(&info->slock, flags);
+
+ tty_wakeup(tty);
+}
+
+
/*
* This routine is called when the serial port gets closed. First, we
* wait for the last remaining data to be sent. Then, we unlink its
@@ -1013,9 +1034,7 @@
}
mxser_shutdown(info);
- if (tty->driver->flush_buffer)
- tty->driver->flush_buffer(tty);
-
+ mxser_flush_buffer(tty);
tty_ldisc_flush(tty);
tty->closing = 0;
@@ -1142,26 +1161,6 @@
return info->xmit_cnt;
}
-static void mxser_flush_buffer(struct tty_struct *tty)
-{
- struct mxser_port *info = tty->driver_data;
- char fcr;
- unsigned long flags;
-
-
- spin_lock_irqsave(&info->slock, flags);
- info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;
-
- fcr = inb(info->ioaddr + UART_FCR);
- outb((fcr | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT),
- info->ioaddr + UART_FCR);
- outb(fcr, info->ioaddr + UART_FCR);
-
- spin_unlock_irqrestore(&info->slock, flags);
-
- tty_wakeup(tty);
-}
-
/*
* ------------------------------------------------------------
* friends of mxser_ioctl()
@@ -1992,6 +1991,7 @@
timeout, char_time);
printk("jiff=%lu...", jiffies);
#endif
+ lock_kernel();
while (!((lsr = inb(info->ioaddr + UART_LSR)) & UART_LSR_TEMT)) {
#ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
printk("lsr = %d (jiff=%lu)...", lsr, jiffies);
@@ -2003,6 +2003,7 @@
break;
}
set_current_state(TASK_RUNNING);
+ unlock_kernel();
#ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT
printk("lsr = %d (jiff=%lu)...done\n", lsr, jiffies);