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Message-ID: <AANLkTimgvFTzAf-kHUnPsGKkRM2TDSAF1Bd51oiyHppI@mail.gmail.com>
Date: Thu, 20 May 2010 22:09:30 +0200
From: Miguel Ojeda <miguel.ojeda.sandonis@...il.com>
To: Greg KH <greg@...ah.com>
Cc: linux-kernel <linux-kernel@...r.kernel.org>,
kristoffer@...sler.com, Andrew Morton <akpm@...ux-foundation.org>,
davem@...emloft.net, Anton Vorontsov <avorontsov@...mvista.com>,
stable@...nel.org
Subject: Re: [alternative-merged] serial-apbuartc-fix-two-problems-related-to-grlib_apbuart_configure.patch
removed from -mm tree
On Thu, May 20, 2010 at 9:52 PM, Miguel Ojeda
<miguel.ojeda.sandonis@...il.com> wrote:
> 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.
CC stable@...nel.org, as .33 is "stable" now and also has apbuart.c.
>
> Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@...il.com>
> Acked-by: Kristoffer Glembo <kristoffer@...sler.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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