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From: Miguel Ojeda on 10 May 2010 09:30
On Sat, May 8, 2010 at 11:58 PM, Miguel Ojeda
<miguel.ojeda.sandonis(a)gmail.com> wrote:
> 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(a)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)

grlib_apbuart_port_nr = 0; should be added here or in apbuart.h better.

> + � � � � � � � 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");
>
>
>
--
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Prev: Handle instruction cache maintenance fault properly
Next: Power Domain Framework