From 952f6d1386b21c5e8db346b805380bf2432e5e9b Mon Sep 17 00:00:00 2001 From: MyungJoo Ham Date: Thu, 10 Nov 2011 10:16:23 +0100 Subject: PM / devfreq: Remove compiler error after irq.h update Added and to avoid a compiler error because linux/irq.h no longer includes linux/module.h after Linux 3.2. Signed-off-by: MyungJoo Ham Signed-off-by: Kyungmin Park Signed-off-by: Rafael J. Wysocki --- drivers/devfreq/devfreq.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers/devfreq') diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index 5d15b812377..d0659253387 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -15,7 +15,9 @@ #include #include #include +#include #include +#include #include #include #include -- cgit v1.2.3-70-g09d2 From 9f3bdd4f937a75c4589a867dc1f8fefe09c1a618 Mon Sep 17 00:00:00 2001 From: Axel Lin Date: Mon, 14 Nov 2011 23:31:29 +0100 Subject: PM / devfreq: fix use after free in devfreq_remove_device In devfreq_remove_device, calling _remove_devfreq will also free devfreq. Don't dereference devfreq->governor->no_central_polling after _remove_devfreq. Signed-off-by: Axel Lin Acked-by: MyungJoo Ham Signed-off-by: Rafael J. Wysocki --- drivers/devfreq/devfreq.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'drivers/devfreq') diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index d0659253387..59d24e9cb8c 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -418,10 +418,14 @@ out: */ int devfreq_remove_device(struct devfreq *devfreq) { + bool central_polling; + if (!devfreq) return -EINVAL; - if (!devfreq->governor->no_central_polling) { + central_polling = !devfreq->governor->no_central_polling; + + if (central_polling) { mutex_lock(&devfreq_list_lock); while (wait_remove_device == devfreq) { mutex_unlock(&devfreq_list_lock); @@ -433,7 +437,7 @@ int devfreq_remove_device(struct devfreq *devfreq) mutex_lock(&devfreq->lock); _remove_devfreq(devfreq, false); /* it unlocks devfreq->lock */ - if (!devfreq->governor->no_central_polling) + if (central_polling) mutex_unlock(&devfreq_list_lock); return 0; -- cgit v1.2.3-70-g09d2 From 6c81f90588972b8631bda4d538ffd0199a3e1b41 Mon Sep 17 00:00:00 2001 From: MyungJoo Ham Date: Mon, 14 Nov 2011 23:31:35 +0100 Subject: PM / devfreq: correct Kconfig dependency Devfreq does not depend on OPP. The dependency is removed. Signed-off-by: MyungJoo Ham Signed-off-by: Kyungmin Park Signed-off-by: Rafael J. Wysocki --- drivers/devfreq/Kconfig | 41 +++++++++++++++++------------------------ 1 file changed, 17 insertions(+), 24 deletions(-) (limited to 'drivers/devfreq') diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig index 643b055ed3c..8f049103708 100644 --- a/drivers/devfreq/Kconfig +++ b/drivers/devfreq/Kconfig @@ -1,36 +1,29 @@ -config ARCH_HAS_DEVFREQ - bool - depends on ARCH_HAS_OPP - help - Denotes that the architecture supports DEVFREQ. If the architecture - supports multiple OPP entries per device and the frequency of the - devices with OPPs may be altered dynamically, the architecture - supports DEVFREQ. - menuconfig PM_DEVFREQ bool "Generic Dynamic Voltage and Frequency Scaling (DVFS) support" - depends on PM_OPP && ARCH_HAS_DEVFREQ help - With OPP support, a device may have a list of frequencies and - voltages available. DEVFREQ, a generic DVFS framework can be - registered for a device with OPP support in order to let the - governor provided to DEVFREQ choose an operating frequency - based on the OPP's list and the policy given with DEVFREQ. + A device may have a list of frequencies and voltages available. + devfreq, a generic DVFS framework can be registered for a device + in order to let the governor provided to devfreq choose an + operating frequency based on the device driver's policy. - Each device may have its own governor and policy. DEVFREQ can + Each device may have its own governor and policy. Devfreq can reevaluate the device state periodically and/or based on the - OPP list changes (each frequency/voltage pair in OPP may be - disabled or enabled). + notification to "nb", a notifier block, of devfreq. - Like some CPUs with CPUFREQ, a device may have multiple clocks. + Like some CPUs with CPUfreq, a device may have multiple clocks. However, because the clock frequencies of a single device are - determined by the single device's state, an instance of DEVFREQ + determined by the single device's state, an instance of devfreq is attached to a single device and returns a "representative" - clock frequency from the OPP of the device, which is also attached - to a device by 1-to-1. The device registering DEVFREQ takes the - responsiblity to "interpret" the frequency listed in OPP and + clock frequency of the device, which is also attached + to a device by 1-to-1. The device registering devfreq takes the + responsiblity to "interpret" the representative frequency and to set its every clock accordingly with the "target" callback - given to DEVFREQ. + given to devfreq. + + When OPP is used with the devfreq device, it is recommended to + register devfreq's nb to the OPP's notifier head. If OPP is + used with the devfreq device, you may use OPP helper + functions defined in devfreq.h. if PM_DEVFREQ -- cgit v1.2.3-70-g09d2