[PATCH] serial core: work around sub-driver bugs
We're presently getting oopses because Bluetooth (and possibly other) drivers
are calling core functions after things have been shut down.
So rather than oopsing, let's drop a warning then take avoiding action, so the
machine survives. Once all the sub-drivers are fixed up we can remove the
take-avoiding-action part.
Signed-off-by: Pavel Machek <pavel@suse.cz>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index 95fb493..cc1faa3 100644
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -71,6 +71,11 @@
void uart_write_wakeup(struct uart_port *port)
{
struct uart_info *info = port->info;
+ /*
+ * This means you called this function _after_ the port was
+ * closed. No cookie for you.
+ */
+ BUG_ON(!info);
tasklet_schedule(&info->tlet);
}
@@ -471,14 +476,26 @@
}
static int
-uart_write(struct tty_struct *tty, const unsigned char * buf, int count)
+uart_write(struct tty_struct *tty, const unsigned char *buf, int count)
{
struct uart_state *state = tty->driver_data;
- struct uart_port *port = state->port;
- struct circ_buf *circ = &state->info->xmit;
+ struct uart_port *port;
+ struct circ_buf *circ;
unsigned long flags;
int c, ret = 0;
+ /*
+ * This means you called this function _after_ the port was
+ * closed. No cookie for you.
+ */
+ if (!state || !state->info) {
+ WARN_ON(1);
+ return -EL3HLT;
+ }
+
+ port = state->port;
+ circ = &state->info->xmit;
+
if (!circ->buf)
return 0;
@@ -521,6 +538,15 @@
struct uart_port *port = state->port;
unsigned long flags;
+ /*
+ * This means you called this function _after_ the port was
+ * closed. No cookie for you.
+ */
+ if (!state || !state->info) {
+ WARN_ON(1);
+ return;
+ }
+
DPRINTK("uart_flush_buffer(%d) called\n", tty->index);
spin_lock_irqsave(&port->lock, flags);