From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754325Ab0EHV7K (ORCPT ); Sat, 8 May 2010 17:59:10 -0400 Received: from mail-fx0-f46.google.com ([209.85.161.46]:47013 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752699Ab0EHV7I (ORCPT ); Sat, 8 May 2010 17:59:08 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=subject:from:to:cc:content-type:date:message-id:mime-version :x-mailer:content-transfer-encoding; b=mt7oqQpK5v5JGsYG2pV7P5KD+I9NqDbet7Qe7PRIR5nHLTcNDdAhQRUXxq+JfSSLLp CBM0Sf2x2XtTgXnPdlEqtWrlyc5QmlgKsoKI9ozrkiUqoBPZzYJwQbfIkwzzkyx2VIAk oDaUbzWM5xDxHFz4gvf9tbp++InvycvQaUv0Q= Subject: [PATCH] [OOPS] apbuart.c: Two problems related to grlib_apbuart_configure() From: Miguel Ojeda To: Andrew Morton , kristoffer@gaisler.com Cc: linux-kernel Content-Type: text/plain; charset="UTF-8" Date: Sat, 08 May 2010 23:58:55 +0200 Message-ID: <1273355935.13191.6.camel@carter> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- --- 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");