brcm_avs_cpufreq_get() calls cpufreq_cpu_get() to get the cpufreq
policy, meanwhile, it also increments the kobject reference count
to mark it busy. However, a corresponding call of cpufreq_cpu_put()
is ignored to decrement the kobject reference count back, which may
lead to a potential stuck risk that the cpuhp thread deadly waits
for dropping of kobject refcount when cpufreq policy free.
With this patch, the cpuhp thread can be easily exercised by
attempting to force an unbind of the CPUfreq driver.
Signed-off-by: chenqiwu <chenqiwu@xiaomi.com>
[ Viresh: Dropped !policy check ]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
What we read back from the register is going to be capped at 32-bits,
and cpufreq_freq_table.frequency is an unsigned int. Avoid any possible
value truncation by using the appropriate return value.
Fixes: de322e0859 ("cpufreq: brcmstb-avs-cpufreq: AVS CPUfreq driver for Broadcom STB SoCs")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Markus Mayer <mmayer@broadcom.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
There is a logical error in brcm_avs_is_firmware_loaded() whereby if the
firmware returns -EINVAL, we will be reporting this as an error. The
comment is correct, the code was not.
Fixes: de322e0859 ("cpufreq: brcmstb-avs-cpufreq: AVS CPUfreq driver for Broadcom STB SoCs")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Markus Mayer <mmayer@broadcom.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
This debug code was helpful while developing the driver, but it isn't
being used for anything anymore.
Signed-off-by: Markus Mayer <mmayer@broadcom.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The cpufreq core is already validating the CPU frequency table after
calling the ->init() callback of the cpufreq drivers and the drivers
don't need to do the same anymore. Though they need to set the
policy->freq_table field directly from the ->init() callback now.
Stop validating the frequency table from brcmstb driver.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The driver core clears the driver data to NULL after device_release
or on probe failure. Thus, it is not needed to manually clear the
device driver data to NULL.
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The AVS GET_PMAP command does return a P-state along with the P-map
information. However, that P-state is the initial P-state when the
P-map was first downloaded to AVS. It is *not* the current P-state.
Therefore, we explicitly retrieve the P-state using the GET_PSTATE
command.
Signed-off-by: Markus Mayer <mmayer@broadcom.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
We extend the brcm_avs_pmap sysfs entry (which issues the GET_PMAP
command to AVS) to include all fields from struct pmap. This means
adding mode (AVS, DVS, DVFS) and state (the P-state) to the output.
Signed-off-by: Markus Mayer <mmayer@broadcom.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Fixes the following sparse warning:
drivers/cpufreq/brcmstb-avs-cpufreq.c:982:18: warning:
symbol 'brcm_avs_cpufreq_attr' was not declared. Should it be static?
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Acked-by: Markus Mayer <mmayer@broadcom.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
In order to aid debugging, we add a debugfs interface to the driver
that allows direct interaction with the AVS co-processor.
The debugfs interface provides a means for reading all and writing some
of the mailbox registers directly from the shell prompt and enables a
user to execute the communications protocol between ARM CPU and AVS CPU
step-by-step.
This interface should be used for debugging purposes only.
Signed-off-by: Markus Mayer <mmayer@broadcom.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This driver supports voltage and frequency scaling on Broadcom STB SoCs
using AVS firmware with DFS and DVFS support.
Actual frequency or voltage scaling is done exclusively by the AVS
firmware. The driver merely provides a standard CPUfreq interface to
other kernel components and userland, and instructs the AVS firmware to
perform frequency or voltage changes on its behalf.
Signed-off-by: Markus Mayer <mmayer@broadcom.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
