From 8a61e12e84597b5f8155ac91b44dea866ccfaac2 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Fri, 20 Sep 2013 10:43:56 -0700 Subject: [PATCH 1/3] acpi-cpufreq: skip loading acpi_cpufreq after intel_pstate If the hw supports intel_pstate and acpi_cpufreq, intel_pstate will get loaded first. acpi_cpufreq_init() will call acpi_cpufreq_early_init() and that will allocate perf data and init those perf data in ACPI core, (that will cover all CPUs). But later it will free them as cpufreq_register_driver(acpi_cpufreq) will fail as intel_pstate is already registered Use cpufreq_get_current_driver() to check if we can skip the acpi_cpufreq loading. Signed-off-by: Yinghai Lu Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/acpi-cpufreq.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cpufreq.c index a1260b4549db..d2c3253e015e 100644 --- a/drivers/cpufreq/acpi-cpufreq.c +++ b/drivers/cpufreq/acpi-cpufreq.c @@ -986,6 +986,10 @@ static int __init acpi_cpufreq_init(void) { int ret; + /* don't keep reloading if cpufreq_driver exists */ + if (cpufreq_get_current_driver()) + return 0; + if (acpi_disabled) return 0; From 26ca8694344af4c833d22590c5b77d6b9cff0722 Mon Sep 17 00:00:00 2001 From: Viresh Kumar Date: Fri, 20 Sep 2013 22:37:31 +0530 Subject: [PATCH 2/3] cpufreq: check cpufreq driver is valid and cpufreq isn't disabled in cpufreq_get() cpufreq_get() can be called from external drivers which might not be aware if cpufreq driver is registered or not. And so we should actually check if cpufreq driver is registered or not and also if cpufreq is active or disabled, at the beginning of cpufreq_get(). Otherwise call to lock_policy_rwsem_read() might hit BUG_ON(!policy). Reported-and-tested-by: Linus Walleij Signed-off-by: Viresh Kumar Reviewed-by: Srivatsa S. Bhat Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/cpufreq.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 89b3c52cd5c3..04548f7023af 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -1460,6 +1460,9 @@ unsigned int cpufreq_get(unsigned int cpu) { unsigned int ret_freq = 0; + if (cpufreq_disabled() || !cpufreq_driver) + return -ENOENT; + if (!down_read_trylock(&cpufreq_rwsem)) return 0; From 116decb7e48b46a8c171bd47f377fa527067f788 Mon Sep 17 00:00:00 2001 From: Sachin Kamat Date: Wed, 18 Sep 2013 10:44:53 +0530 Subject: [PATCH 3/3] cpufreq: exynos5440: Fix potential NULL pointer dereference If 'dvfs_info' is NULL (due to devm_kzalloc failure) the failure error message would try to dereference it. Use 'pdev' instead. Signed-off-by: Sachin Kamat Acked-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/exynos5440-cpufreq.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/cpufreq/exynos5440-cpufreq.c b/drivers/cpufreq/exynos5440-cpufreq.c index d514c152fd1a..be5380ecdcd4 100644 --- a/drivers/cpufreq/exynos5440-cpufreq.c +++ b/drivers/cpufreq/exynos5440-cpufreq.c @@ -457,7 +457,7 @@ static int exynos_cpufreq_probe(struct platform_device *pdev) opp_free_cpufreq_table(dvfs_info->dev, &dvfs_info->freq_table); err_put_node: of_node_put(np); - dev_err(dvfs_info->dev, "%s: failed initialization\n", __func__); + dev_err(&pdev->dev, "%s: failed initialization\n", __func__); return ret; }