From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936548Ab3DIV5E (ORCPT ); Tue, 9 Apr 2013 17:57:04 -0400 Received: from mail-oa0-f73.google.com ([209.85.219.73]:38235 "EHLO mail-oa0-f73.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761010Ab3DIV5C (ORCPT ); Tue, 9 Apr 2013 17:57:02 -0400 From: Andrew Bresticker To: Zhang Rui , Eduardo Valentin Cc: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Andrew Bresticker Subject: [PATCH] thermal: cpu_cooling: fix handling of invalid frequency table entries Date: Tue, 9 Apr 2013 14:56:56 -0700 Message-Id: <1365544616-10003-1-git-send-email-abrestic@chromium.org> X-Mailer: git-send-email 1.8.1.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org get_cpu_frequency() goes into an infinite loop if any of the entries in the CPU frequency table are invalid. This patch fixes that case and, with a separate counter for frequency levels, ensures that the n-th valid frequency level is returned. Signed-off-by: Andrew Bresticker --- drivers/thermal/cpu_cooling.c | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) diff --git a/drivers/thermal/cpu_cooling.c b/drivers/thermal/cpu_cooling.c index 836828e..e6db441 100644 --- a/drivers/thermal/cpu_cooling.c +++ b/drivers/thermal/cpu_cooling.c @@ -124,14 +124,14 @@ static int is_cpufreq_valid(int cpu) static unsigned int get_cpu_frequency(unsigned int cpu, unsigned long level) { int ret = 0, i = 0; - unsigned long level_index; + unsigned long level_index = 0; bool descend = false; struct cpufreq_frequency_table *table = cpufreq_frequency_get_table(cpu); if (!table) return ret; - while (table[i].frequency != CPUFREQ_TABLE_END) { + for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) { if (table[i].frequency == CPUFREQ_ENTRY_INVALID) continue; @@ -143,24 +143,25 @@ static unsigned int get_cpu_frequency(unsigned int cpu, unsigned long level) } /*return if level matched and table in descending order*/ - if (descend && i == level) + if (descend && level_index == level) return table[i].frequency; - i++; + level_index++; } i--; + level_index--; - if (level > i || descend) + if (level > level_index || descend) return ret; - level_index = i - level; + level = level_index - level; /*Scan the table in reverse order and match the level*/ - while (i >= 0) { + for (; i >= 0; i--) { if (table[i].frequency == CPUFREQ_ENTRY_INVALID) continue; /*return if level matched*/ - if (i == level_index) + if (level_index == level) return table[i].frequency; - i--; + level_index--; } return ret; } -- 1.8.1.3