/* * Copyright (c) 2016 Laurent Pinchart * * Permission to use, copy, modify, distribute, and sell this software and its * documentation for any purpose is hereby granted without fee, provided that * the above copyright notice appear in all copies and that both that copyright * notice and this permission notice appear in supporting documentation, and * that the name of the copyright holders not be used in advertising or * publicity pertaining to distribution of the software without specific, * written prior permission. The copyright holders make no representations * about the suitability of this software for any purpose. It is provided "as * is" without express or implied warranty. * * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE * OF THIS SOFTWARE. */ #ifndef __DRM_FOURCC_H__ #define __DRM_FOURCC_H__ #include #include /** * struct drm_format_info - information about a DRM format * @format: 4CC format identifier (DRM_FORMAT_*) * @depth: Color depth (number of bits per pixel excluding padding bits), * valid for a subset of RGB formats only. This is a legacy field, do not * use in new code and set to 0 for new formats. * @num_planes: Number of color planes (1 to 3) * @cpp: Number of bytes per pixel (per plane) * @hsub: Horizontal chroma subsampling factor * @vsub: Vertical chroma subsampling factor */ struct drm_format_info { u32 format; u8 depth; u8 num_planes; u8 cpp[3]; u8 hsub; u8 vsub; }; /** * struct drm_format_name_buf - name of a DRM format * @str: string buffer containing the format name */ struct drm_format_name_buf { char str[32]; }; const struct drm_format_info *__drm_format_info(u32 format); const struct drm_format_info *drm_format_info(u32 format); uint32_t drm_mode_legacy_fb_format(uint32_t bpp, uint32_t depth); int drm_format_num_planes(uint32_t format); int drm_format_plane_cpp(uint32_t format, int plane); int drm_format_horz_chroma_subsampling(uint32_t format); int drm_format_vert_chroma_subsampling(uint32_t format); int drm_format_plane_width(int width, uint32_t format, int plane); int drm_format_plane_height(int height, uint32_t format, int plane); const char *drm_get_format_name(uint32_t format, struct drm_format_name_buf *buf); #endif /* __DRM_FOURCC_H__ */ ption>
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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 /tools/perf/arch/arm64
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 'tools/perf/arch/arm64')