From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757466Ab3JRWwT (ORCPT ); Fri, 18 Oct 2013 18:52:19 -0400 Received: from mail-ea0-f181.google.com ([209.85.215.181]:45291 "EHLO mail-ea0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757013Ab3JRWwN (ORCPT ); Fri, 18 Oct 2013 18:52:13 -0400 From: Thierry Reding To: Daniel Lezcano , Thomas Gleixner Cc: Arnd Bergmann , Rob Herring , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] clocksource: Do not drop unheld reference on device node Date: Sat, 19 Oct 2013 00:49:48 +0200 Message-Id: <1382136588-15320-1-git-send-email-treding@nvidia.com> X-Mailer: git-send-email 1.8.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When booting a recent kernel on ARM with OF_DYNAMIC enabled, the kernel warns about the following: [ 0.000000] ERROR: Bad of_node_put() on /timer@50004600 [ 0.000000] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.12.0-rc5-next-20131017-00077-gedfd827-dirty #406 [ 0.000000] [] (unwind_backtrace+0x0/0xf4) from [] (show_stack+0x10/0x14) [ 0.000000] [] (show_stack+0x10/0x14) from [] (dump_stack+0x9c/0xc8) [ 0.000000] [] (dump_stack+0x9c/0xc8) from [] (of_node_release+0x90/0x9c) [ 0.000000] [] (of_node_release+0x90/0x9c) from [] (of_find_matching_node_and_match+0x78/0xb4) [ 0.000000] [] (of_find_matching_node_and_match+0x78/0xb4) from [] (clocksource_of_init+0x60/0x70) [ 0.000000] [] (clocksource_of_init+0x60/0x70) from [] (start_kernel+0x1f4/0x33c) [ 0.000000] [] (start_kernel+0x1f4/0x33c) from [<80008074>] (0x80008074) This is caused by clocksource_of_init() dropping a reference on the device node that it never took. The reference taken by the loop is implicitly dropped on subsequent iterations. See the implementation of and the comment on top of the of_find_matching_node_and_match() function for reference (no pun intended). Signed-off-by: Thierry Reding --- drivers/clocksource/clksrc-of.c | 1 - 1 file changed, 1 deletion(-) diff --git a/drivers/clocksource/clksrc-of.c b/drivers/clocksource/clksrc-of.c index 35639cf4..b9ddd9e 100644 --- a/drivers/clocksource/clksrc-of.c +++ b/drivers/clocksource/clksrc-of.c @@ -35,6 +35,5 @@ void __init clocksource_of_init(void) init_func = match->data; init_func(np); - of_node_put(np); } } -- 1.8.4