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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>
This commit is contained in:
Andre Przywara 2015-05-21 17:26:14 +01:00 committed by Greg Kroah-Hartman
parent 7798edeebc
commit 49bb3c862c
1 changed files with 20 additions and 16 deletions
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36
drivers/tty/serial/amba-pl011.c
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@ -2135,6 +2135,23 @@ static int pl011_probe_dt_alias(int index, struct device *dev)
return ret; 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) static int pl011_probe(struct amba_device *dev, const struct amba_id *id)
{ {
struct uart_amba_port *uap; struct uart_amba_port *uap;
@ -2200,10 +2217,8 @@ static int pl011_probe(struct amba_device *dev, const struct amba_id *id)
} }
ret = uart_add_one_port(&amba_reg, &uap->port); ret = uart_add_one_port(&amba_reg, &uap->port);
if (ret) { if (ret)
amba_ports[i] = NULL; pl011_unregister_port(uap);
uart_unregister_driver(&amba_reg);
}
return ret; return ret;
} }
@ -2211,20 +2226,9 @@ static int pl011_probe(struct amba_device *dev, const struct amba_id *id)
static int pl011_remove(struct amba_device *dev) static int pl011_remove(struct amba_device *dev)
{ {
struct uart_amba_port *uap = amba_get_drvdata(dev); struct uart_amba_port *uap = amba_get_drvdata(dev);
bool busy = false;
int i;
uart_remove_one_port(&amba_reg, &uap->port); uart_remove_one_port(&amba_reg, &uap->port);
pl011_unregister_port(uap);
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);
return 0; return 0;
} }