#ifndef _UAPI_UVESAFB_H #define _UAPI_UVESAFB_H #include struct v86_regs { __u32 ebx; __u32 ecx; __u32 edx; __u32 esi; __u32 edi; __u32 ebp; __u32 eax; __u32 eip; __u32 eflags; __u32 esp; __u16 cs; __u16 ss; __u16 es; __u16 ds; __u16 fs; __u16 gs; }; /* Task flags */ #define TF_VBEIB 0x01 #define TF_BUF_ESDI 0x02 #define TF_BUF_ESBX 0x04 #define TF_BUF_RET 0x08 #define TF_EXIT 0x10 struct uvesafb_task { __u8 flags; int buf_len; struct v86_regs regs; }; /* Constants for the capabilities field * in vbe_ib */ #define VBE_CAP_CAN_SWITCH_DAC 0x01 #define VBE_CAP_VGACOMPAT 0x02 /* The VBE Info Block */ struct vbe_ib { char vbe_signature[4]; __u16 vbe_version; __u32 oem_string_ptr; __u32 capabilities; __u32 mode_list_ptr; __u16 total_memory; __u16 oem_software_rev; __u32 oem_vendor_name_ptr; __u32 oem_product_name_ptr; __u32 oem_product_rev_ptr; __u8 reserved[222]; char oem_data[256]; char misc_data[512]; } __attribute__ ((packed)); #endif /* _UAPI_UVESAFB_H */ .form.submit();'> net-next plumbingsTobias Klauser
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authorSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>2017-02-03 14:18:39 -0800
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2017-02-04 00:11:08 +0100
commit6e978b22efa1db9f6e71b24440b5f1d93e968ee3 (patch)
treec666f7a26b860674848949e39a610222b0723f89 /include/trace
parent3c223c19aea85d3dda1416c187915f4a30b04b1f (diff)
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>
Diffstat (limited to 'include/trace')