/*
* This header declares the utility functions used by "Gadget Zero", plus
* interfaces to its two single-configuration function drivers.
*/
#ifndef __G_ZERO_H
#define __G_ZERO_H
#define GZERO_BULK_BUFLEN 4096
#define GZERO_QLEN 32
#define GZERO_ISOC_INTERVAL 4
#define GZERO_ISOC_MAXPACKET 1024
#define GZERO_SS_BULK_QLEN 1
#define GZERO_SS_ISO_QLEN 8
struct usb_zero_options {
unsigned pattern;
unsigned isoc_interval;
unsigned isoc_maxpacket;
unsigned isoc_mult;
unsigned isoc_maxburst;
unsigned bulk_buflen;
unsigned qlen;
unsigned ss_bulk_qlen;
unsigned ss_iso_qlen;
};
struct f_ss_opts {
struct usb_function_instance func_inst;
unsigned pattern;
unsigned isoc_interval;
unsigned isoc_maxpacket;
unsigned isoc_mult;
unsigned isoc_maxburst;
unsigned bulk_buflen;
unsigned bulk_qlen;
unsigned iso_qlen;
/*
* Read/write access to configfs attributes is handled by configfs.
*
* This is to protect the data from concurrent access by read/write
* and create symlink/remove symlink.
*/
struct mutex lock;
int refcnt;
};
struct f_lb_opts {
struct usb_function_instance func_inst;
unsigned bulk_buflen;
unsigned qlen;
/*
* Read/write access to configfs attributes is handled by configfs.
*
* This is to protect the data from concurrent access by read/write
* and create symlink/remove symlink.
*/
struct mutex lock;
int refcnt;
};
void lb_modexit(void);
int lb_modinit(void);
/* common utilities */
void disable_endpoints(struct usb_composite_dev *cdev,
struct usb_ep *in, struct usb_ep *out,
struct usb_ep *iso_in, struct usb_ep *iso_out);
#endif /* __G_ZERO_H */
git/'>summaryrefslogtreecommitdiff
cpufreq: intel_pstate: Disable energy efficiency optimization
Some Kabylake desktop processors may not reach max turbo when running in
HWP mode, even if running under sustained 100% utilization.
This occurs when the HWP.EPP (Energy Performance Preference) is set to
"balance_power" (0x80) -- the default on most systems.
It occurs because the platform BIOS may erroneously enable an
energy-efficiency setting -- MSR_IA32_POWER_CTL BIT-EE, which is not
recommended to be enabled on this SKU.
On the failing systems, this BIOS issue was not discovered when the
desktop motherboard was tested with Windows, because the BIOS also
neglects to provide the ACPI/CPPC table, that Windows requires to enable
HWP, and so Windows runs in legacy P-state mode, where this setting has
no effect.
Linux' intel_pstate driver does not require ACPI/CPPC to enable HWP, and
so it runs in HWP mode, exposing this incorrect BIOS configuration.
There are several ways to address this problem.
First, Linux can also run in legacy P-state mode on this system.
As intel_pstate is how Linux enables HWP, booting with
"intel_pstate=disable"
will run in acpi-cpufreq/ondemand legacy p-state mode.
Or second, the "performance" governor can be used with intel_pstate,
which will modify HWP.EPP to 0.
Or third, starting in 4.10, the
/sys/devices/system/cpu/cpufreq/policy*/energy_performance_preference
attribute in can be updated from "balance_power" to "performance".
Or fourth, apply this patch, which fixes the erroneous setting of
MSR_IA32_POWER_CTL BIT_EE on this model, allowing the default
configuration to function as designed.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Reviewed-by: Len Brown <len.brown@intel.com>
Cc: 4.6+ <stable@vger.kernel.org> # 4.6+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>