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From: Miguel Ojeda on 20 May 2010 16:00
Hi,

I found two problems using the Simics' sunfire target. It occurs as well on real machines.

1. At grlib_apbuart_configure() in apbuart.c, prop can be NULL if
"clock-frequency" doesn't exist in the OF tree:

/* Get bus frequency */
rp = of_find_node_by_path("/");
rp = of_get_next_child(rp, NULL);
prop = of_get_property(rp, "clock-frequency", NULL);
freq_khz = *prop;

2. In addition, apbuart.c does not check if there aren't any ports
configured after calls to grlib_apbuart_configure(), so other oops will
occur if no port was configured (e.g. uart_set_options() because of
port->ops).

In order to solve that, I added a check after both of the calls to
grlib_apbuart_configure().

The patch that I provide below prevents both problems in the Simics'
sunfire target. In addition, it warns the users if no ports were found.

Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis(a)gmail.com>
Acked-by: Kristoffer Glembo <kristoffer(a)gaisler.com>
---
--- drivers/serial/apbuart.c.orig 2010-04-26 16:48:30.000000000 +0200
+++ drivers/serial/apbuart.c 2010-05-11 15:21:28.984666230 +0200
@@ -525,6 +525,9 @@ static void grlib_apbuart_configure(void
static int __init apbuart_console_init(void)
{
grlib_apbuart_configure();
+ if (grlib_apbuart_port_nr == 0)
+ return 0;
+
register_console(&grlib_apbuart_console);
return 0;
}
@@ -612,6 +615,10 @@ static void grlib_apbuart_configure(void
rp = of_find_node_by_path("/");
rp = of_get_next_child(rp, NULL);
prop = of_get_property(rp, "clock-frequency", NULL);
+ if (prop == NULL) {
+ grlib_apbuart_port_nr = 0;
+ return;
+ }
freq_khz = *prop;

line = 0;
@@ -666,6 +673,10 @@ static int __init grlib_apbuart_init(voi

/* Find all APBUARTS in device the tree and initialize their ports */
grlib_apbuart_configure();
+ if (grlib_apbuart_port_nr == 0) {
+ printk(KERN_INFO "Serial: GRLIB APBUART: No ports found.\n");
+ return -ENODEV;
+ }

printk(KERN_INFO "Serial: GRLIB APBUART driver\n");



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Prev: [GIT PULL] perf fix (preempt count imbalance on buffer)
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