From a66b2e503fc79fff6632d02ef5a0ee47c1d2553d Mon Sep 17 00:00:00 2001 From: "Srivatsa S. Bhat" Date: Wed, 15 May 2013 21:47:17 +0200 Subject: [PATCH] cpufreq: Preserve sysfs files across suspend/resume The file permissions of cpufreq per-cpu sysfs files are not preserved across suspend/resume because we internally go through the CPU Hotplug path which reinitializes the file permissions on CPU online. But the user is not supposed to know that we are using CPU hotplug internally within suspend/resume (IOW, the kernel should not silently wreck the user-set file permissions across a suspend cycle). Therefore, we need to preserve the file permissions as they are across suspend/resume. The simplest way to achieve that is to just not touch the sysfs files at all - ie., just ignore the CPU hotplug notifications in the suspend/resume path (_FROZEN) in the cpufreq hotplug callback. Reported-by: Robert Jarzmik Reported-by: Durgadoss R Signed-off-by: Srivatsa S. Bhat Acked-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/cpufreq.c | 4 +--- drivers/cpufreq/cpufreq_stats.c | 7 ++++--- 2 files changed, 5 insertions(+), 6 deletions(-) diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index b7acfd153bf9..4b8c7f297d74 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -1832,15 +1832,13 @@ static int __cpuinit cpufreq_cpu_callback(struct notifier_block *nfb, if (dev) { switch (action) { case CPU_ONLINE: - case CPU_ONLINE_FROZEN: cpufreq_add_dev(dev, NULL); break; case CPU_DOWN_PREPARE: - case CPU_DOWN_PREPARE_FROZEN: + case CPU_UP_CANCELED_FROZEN: __cpufreq_remove_dev(dev, NULL); break; case CPU_DOWN_FAILED: - case CPU_DOWN_FAILED_FROZEN: cpufreq_add_dev(dev, NULL); break; } diff --git a/drivers/cpufreq/cpufreq_stats.c b/drivers/cpufreq/cpufreq_stats.c index bfd6273fd873..fb65decffa28 100644 --- a/drivers/cpufreq/cpufreq_stats.c +++ b/drivers/cpufreq/cpufreq_stats.c @@ -349,15 +349,16 @@ static int __cpuinit cpufreq_stat_cpu_callback(struct notifier_block *nfb, switch (action) { case CPU_ONLINE: - case CPU_ONLINE_FROZEN: cpufreq_update_policy(cpu); break; case CPU_DOWN_PREPARE: - case CPU_DOWN_PREPARE_FROZEN: cpufreq_stats_free_sysfs(cpu); break; case CPU_DEAD: - case CPU_DEAD_FROZEN: + cpufreq_stats_free_table(cpu); + break; + case CPU_UP_CANCELED_FROZEN: + cpufreq_stats_free_sysfs(cpu); cpufreq_stats_free_table(cpu); break; } -- 2.20.1