Solved Intel i915 rc6 power saving enabled?

J

JAW

How can you verify that the rc6 power saving is enabled on a Intel HD6000 based gpu?

I have the following in my /boot/loader.conf;
Code: 
# Enable GPU power-saving idle states
drm.i915.enable_rc6=7

However I see no mention of it from dmesg or sysctl, e.g.
dmesg | grep rc6
<nothing>

sysctl -a | grep rc6
<nothing>

dmesg | grep drm
Code: 
drmn0: <drmn> on vgapci0
vgapci0: child drmn0 requested pci_enable_io
vgapci0: child drmn0 requested pci_enable_io
[drm] Unable to create a private tmpfs mount, hugepage support will be disabled(-19).
[drm] Got stolen memory base 0x8c000000, size 0x4000000
[drm] Supports vblank timestamp caching Rev 2 (21.10.2013).
[drm] Driver supports precise vblank timestamp query.
[drm] Connector eDP-1: get mode from tunables:
[drm]   - kern.vt.fb.modes.eDP-1
[drm]   - kern.vt.fb.default_mode
[drm] Connector DP-1: get mode from tunables:
[drm]   - kern.vt.fb.modes.DP-1
[drm]   - kern.vt.fb.default_mode
[drm] Connector HDMI-A-1: get mode from tunables:
[drm]   - kern.vt.fb.modes.HDMI-A-1
[drm]   - kern.vt.fb.default_mode
[drm] Connector DP-2: get mode from tunables:
[drm]   - kern.vt.fb.modes.DP-2
[drm]   - kern.vt.fb.default_mode
[drm] Connector HDMI-A-2: get mode from tunables:
[drm]   - kern.vt.fb.modes.HDMI-A-2
[drm]   - kern.vt.fb.default_mode
[drm] Initialized i915 1.6.0 20171222 for drmn0 on minor 0
name=drmn0 flags=0x0 stride=5760 bpp=32
drmn0: fb0: inteldrmfb frame buffer device

sysctl -a | grep drm
Code: 
sys.class.drm.card0-HDMI-A-2.modes:
sys.class.drm.card0-HDMI-A-2.dpms: Off
sys.class.drm.card0-HDMI-A-2.enabled: disabled
sys.class.drm.card0-DP-2.modes:
sys.class.drm.card0-DP-2.dpms: Off
sys.class.drm.card0-DP-2.enabled: disabled
sys.class.drm.card0-HDMI-A-1.modes:
sys.class.drm.card0-HDMI-A-1.dpms: Off
sys.class.drm.card0-HDMI-A-1.enabled: disabled
sys.class.drm.card0-DP-1.modes:
sys.class.drm.card0-DP-1.dpms: Off
sys.class.drm.card0-DP-1.enabled: disabled
sys.class.drm.card0-eDP-1.modes: 1440x900
sys.class.drm.card0-eDP-1.dpms: On
sys.class.drm.card0-eDP-1.enabled: enabled
sys.class.drm.version: drm 1.1.0 20060810
dev.drmn.0.%parent: vgapci0
dev.drmn.0.%pnpinfo:
dev.drmn.0.%location:
dev.drmn.0.%driver: drmn
dev.drmn.0.%desc: drmn
dev.drmn.%parent:
dev.drm.0.PCI_ID: 8086:1626
dev.drm.128.PCI_ID: 8086:1626
dev.drm.always_interruptible: 0
dev.drm.error_panic: 0
dev.drm.drm_debug_persist: 0
dev.drm.skip_ddb: 0
dev.drm.drm_debug: 0
compat.linuxkpi.drm_timestamp_precision_usec: 20
compat.linuxkpi.drm_vblankoffdelay: 5000
compat.linuxkpi.drm_poll: 1
compat.linuxkpi.drm_drm_fbdev_overalloc: 100
compat.linuxkpi.drm_fbdev_emulation: 1
compat.linuxkpi.drm_edid_firmware:
compat.linuxkpi.drm_edid_fixup: 6
compat.linuxkpi.drm_debug: 0
compat.linuxkpi.drm_dp_aux_i2c_transfer_size: 16
compat.linuxkpi.drm_dp_aux_i2c_speed_khz: 10

Thanks,
James
 
If you're using linuxkpi-based graphics/drm-kmod then that line ("drm.i915.enable_rc6=7") isn't gonna work at all.
You need something like this:
Code: 
# INTEL DRM WITH graphics/drm-kmod PACKAGE (NEW)
# SKIP UNNECESSARY MODE SETS AT BOOT TIME
  compat.linuxkpi.fastboot=1
# USE SEMAPHORES FOR INTER RING SYNC
  compat.linuxkpi.semaphores=1
# ENABLE POWER SAVING RENDER C-STATE 6
  compat.linuxkpi.enable_rc6=7
# ENABLE POWER SAVING DISPLAY C-STATES
  compat.linuxkpi.enable_dc=2
# ENABLE FRAME BUFFER COMPRESSION FOR POWER SAVINGS
  compat.linuxkpi.enable_fbc=1
*Taken from vermaden's incredibly useful website*
 
  • Thanks
Reactions: JAW
patovm04 said:
If you're using linuxkpi-based graphics/drm-kmod then that line ("drm.i915.enable_rc6=7") isn't gonna work at all.
Click to expand...

Seems that the module params keep changing, so as you pointed out the one I was previously using is now useless with the latest default version (v4.16) of graphics/drm-kmod.

The best documentation I've found for which params are actually available seems to be the source itself;
https://github.com/FreeBSDDesktop/kms-drm/blob/drm-v4.16/drivers/gpu/drm/i915/i915_params.c
https://github.com/FreeBSDDesktop/kms-drm/blob/drm-v4.16/drivers/gpu/drm/i915/i915_params.h

Based on the links above I added the following in boot/loader.conf;
Code: 
# Try to skip unnecessary mode sets at boot time
compat.linuxkpi.i915_fastboot=1

# Enable power-saving display C-states (0=disable; 1=up to DC5; 2=up to DC6)
compat.linuxkpi.i915_enable_dc=2

# Disable display power wells when possible (0=power wells always on, 1=power wells disabled when possible)
compat.linuxkpi.i915_disable_power_well=1

# Enable frame buffer compression for power savings
compat.linuxkpi.i915_enable_fbc=1


Reboot then check changes have taken effect;
sysctl compat.linuxkpi | grep i915
 
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