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* [PATCH] [OOPS] apbuart.c: Two problems related to grlib_apbuart_configure()
@ 2010-05-08 21:58 Miguel Ojeda
  2010-05-10 13:20 ` Miguel Ojeda
                   ` (2 more replies)
  0 siblings, 3 replies; 7+ messages in thread
From: Miguel Ojeda @ 2010-05-08 21:58 UTC (permalink / raw)
  To: Andrew Morton, kristoffer; +Cc: linux-kernel

Hi,

I found two problems using the Simics' sunfire target, so maybe the
following does not occur in 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.

Tested against 2.6.33.3. Please review.

Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
---
--- drivers/serial/apbuart.c.orig	2010-04-26 16:48:30.000000000 +0200
+++ drivers/serial/apbuart.c	2010-05-08 23:50:36.786148571 +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 +615,8 @@ 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)
+		return;
 	freq_khz = *prop;
 
 	line = 0;
@@ -666,6 +671,11 @@ 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",
+			__FILE__);
+		return 0;
+	}
 
 	printk(KERN_INFO "Serial: GRLIB APBUART driver\n");
 


^ permalink raw reply	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2010-05-20 20:09 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2010-05-08 21:58 [PATCH] [OOPS] apbuart.c: Two problems related to grlib_apbuart_configure() Miguel Ojeda
2010-05-10 13:20 ` Miguel Ojeda
2010-05-11  7:11   ` Kristoffer Glembo
2010-05-11 13:38 ` Miguel Ojeda
2010-05-11 13:42   ` Kristoffer Glembo
2010-05-20 19:52 ` [alternative-merged] serial-apbuartc-fix-two-problems-related-to-grlib_apbuart_configure.patch removed from -mm tree Miguel Ojeda
2010-05-20 20:09   ` Miguel Ojeda

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