drivers: PL011: avoid potential unregister_driver call
Although we care about not unregistering the driver if there are
still ports connected during the .remove callback, we do miss this
check in the pl011_probe function. So if the current port allocation
fails, but there are other ports already registered, we will kill
those.
So factor out the port removal into a separate function and use that
in the probe function, too.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Tested-by: Mark Langsdorf <mlangsdo@redhat.com>
Tested-by: Naresh Bhat <nbhat@cavium.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index f5bd842..b4de23c 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -2135,6 +2135,23 @@
return ret;
}
+/* unregisters the driver also if no more ports are left */
+static void pl011_unregister_port(struct uart_amba_port *uap)
+{
+ int i;
+ bool busy = false;
+
+ for (i = 0; i < ARRAY_SIZE(amba_ports); i++) {
+ if (amba_ports[i] == uap)
+ amba_ports[i] = NULL;
+ else if (amba_ports[i])
+ busy = true;
+ }
+ pl011_dma_remove(uap);
+ if (!busy)
+ uart_unregister_driver(&amba_reg);
+}
+
static int pl011_probe(struct amba_device *dev, const struct amba_id *id)
{
struct uart_amba_port *uap;
@@ -2200,10 +2217,8 @@
}
ret = uart_add_one_port(&amba_reg, &uap->port);
- if (ret) {
- amba_ports[i] = NULL;
- uart_unregister_driver(&amba_reg);
- }
+ if (ret)
+ pl011_unregister_port(uap);
return ret;
}
@@ -2211,20 +2226,9 @@
static int pl011_remove(struct amba_device *dev)
{
struct uart_amba_port *uap = amba_get_drvdata(dev);
- bool busy = false;
- int i;
uart_remove_one_port(&amba_reg, &uap->port);
-
- for (i = 0; i < ARRAY_SIZE(amba_ports); i++)
- if (amba_ports[i] == uap)
- amba_ports[i] = NULL;
- else if (amba_ports[i])
- busy = true;
-
- pl011_dma_remove(uap);
- if (!busy)
- uart_unregister_driver(&amba_reg);
+ pl011_unregister_port(uap);
return 0;
}