[SERIAL] Fix Bug 4900: S3 resume oops with irattach - Thinkpad A21m
If we fail to re-startup a serial port on resume, shut it down
immediately and mark it as an error condition.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index 427a238..2331296 100644
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -209,33 +209,45 @@
struct uart_info *info = state->info;
struct uart_port *port = state->port;
- if (!(info->flags & UIF_INITIALIZED))
- return;
+ /*
+ * Set the TTY IO error marker
+ */
+ if (info->tty)
+ set_bit(TTY_IO_ERROR, &info->tty->flags);
+
+ if (info->flags & UIF_INITIALIZED) {
+ info->flags &= ~UIF_INITIALIZED;
+
+ /*
+ * Turn off DTR and RTS early.
+ */
+ if (!info->tty || (info->tty->termios->c_cflag & HUPCL))
+ uart_clear_mctrl(port, TIOCM_DTR | TIOCM_RTS);
+
+ /*
+ * clear delta_msr_wait queue to avoid mem leaks: we may free
+ * the irq here so the queue might never be woken up. Note
+ * that we won't end up waiting on delta_msr_wait again since
+ * any outstanding file descriptors should be pointing at
+ * hung_up_tty_fops now.
+ */
+ wake_up_interruptible(&info->delta_msr_wait);
+
+ /*
+ * Free the IRQ and disable the port.
+ */
+ port->ops->shutdown(port);
+
+ /*
+ * Ensure that the IRQ handler isn't running on another CPU.
+ */
+ synchronize_irq(port->irq);
+ }
/*
- * Turn off DTR and RTS early.
+ * kill off our tasklet
*/
- if (!info->tty || (info->tty->termios->c_cflag & HUPCL))
- uart_clear_mctrl(port, TIOCM_DTR | TIOCM_RTS);
-
- /*
- * clear delta_msr_wait queue to avoid mem leaks: we may free
- * the irq here so the queue might never be woken up. Note
- * that we won't end up waiting on delta_msr_wait again since
- * any outstanding file descriptors should be pointing at
- * hung_up_tty_fops now.
- */
- wake_up_interruptible(&info->delta_msr_wait);
-
- /*
- * Free the IRQ and disable the port.
- */
- port->ops->shutdown(port);
-
- /*
- * Ensure that the IRQ handler isn't running on another CPU.
- */
- synchronize_irq(port->irq);
+ tasklet_kill(&info->tlet);
/*
* Free the transmit buffer page.
@@ -244,15 +256,6 @@
free_page((unsigned long)info->xmit.buf);
info->xmit.buf = NULL;
}
-
- /*
- * kill off our tasklet
- */
- tasklet_kill(&info->tlet);
- if (info->tty)
- set_bit(TTY_IO_ERROR, &info->tty->flags);
-
- info->flags &= ~UIF_INITIALIZED;
}
/**
@@ -1928,14 +1931,25 @@
if (state->info && state->info->flags & UIF_INITIALIZED) {
struct uart_ops *ops = port->ops;
+ int ret;
ops->set_mctrl(port, 0);
- ops->startup(port);
- uart_change_speed(state, NULL);
- spin_lock_irq(&port->lock);
- ops->set_mctrl(port, port->mctrl);
- ops->start_tx(port);
- spin_unlock_irq(&port->lock);
+ ret = ops->startup(port);
+ if (ret == 0) {
+ uart_change_speed(state, NULL);
+ spin_lock_irq(&port->lock);
+ ops->set_mctrl(port, port->mctrl);
+ ops->start_tx(port);
+ spin_unlock_irq(&port->lock);
+ } else {
+ /*
+ * Failed to resume - maybe hardware went away?
+ * Clear the "initialized" flag so we won't try
+ * to call the low level drivers shutdown method.
+ */
+ state->info->flags &= ~UIF_INITIALIZED;
+ uart_shutdown(state);
+ }
}
up(&state->sem);
