Bug 94387 - Approx 35W more power usage in multi-screen
Summary: Approx 35W more power usage in multi-screen
Alias: None
Product: DRI
Classification: Unclassified
Component: DRM/Radeon (show other bugs)
Version: unspecified
Hardware: Other All
: medium normal
Assignee: Default DRI bug account
QA Contact:
Depends on:
Reported: 2016-03-03 12:29 UTC by Steve
Modified: 2019-11-19 09:13 UTC (History)
0 users

See Also:
i915 platform:
i915 features:

dmesg output (80.71 KB, text/plain)
2016-03-03 21:27 UTC, Steve
no flags Details
Xorg.0.log as requested (63.45 KB, text/plain)
2016-03-03 21:27 UTC, Steve
no flags Details

Description Steve 2016-03-03 12:29:09 UTC
When using multiscreen on the radeon driver, dpm is disabled. This means the adapter draws approx 35W more power due to no dynamic power management.

While I would love to continue to use this card + radeon driver (which works perfectly in all other regards), the extra heat generated make this not an option.

Multi-monitor configs are becoming more and more common - but they are almost unusable power / heat wise.

While this is probably a pipe-dream - what are the chances of getting some form of power management that isn't just "severely cripple the card"?
Comment 1 Alex Deucher 2016-03-03 14:19:01 UTC
DPM works with multi-monitor.  What chip are you using?  Please attach your xorg log and dmesg output.
Comment 2 Steve 2016-03-03 21:27:00 UTC
Created attachment 122105 [details]
dmesg output

You are right - I notice:
[    3.055513] [drm] Loading BARTS Microcode
[    3.055579] [drm] Internal thermal controller with fan control
[    3.061488] [drm] radeon: dpm initialized

This is interesting - as the fan sure works harder under the radeon driver than the fglrx - and you can feel the extra heat coming out the back of the card.

Is there any further information I can supply re power levels on the card to try and see what causes the extra power / heat usage?
Comment 3 Steve 2016-03-03 21:27:28 UTC
Created attachment 122106 [details]
Xorg.0.log as requested
Comment 4 Steve 2016-03-05 04:04:40 UTC
I've been digging more into this.... I have 3 x displays - 2 x DVI, 1 x DP.

Looking into debugfs, I can see that the clocks never change from sclk 900MHz, mclk: 105000.

# cat /sys/kernel/debug/dri/64/radeon_pm_info
uvd    vclk: 0 dclk: 0
power level 2    sclk: 90000 mclk: 105000 vddc: 1175 vddci: 1150

My kernel options are:
# for i in /sys/class/drm/card0/device/power_*; do echo "$i: `cat $i`"; done
/sys/class/drm/card0/device/power_dpm_force_performance_level: auto
/sys/class/drm/card0/device/power_dpm_state: balanced
/sys/class/drm/card0/device/power_method: dpm
/sys/class/drm/card0/device/power_profile: default

# for i in /sys/module/radeon/parameters/*; do echo "$i: `cat $i`"; done
/sys/module/radeon/parameters/agpmode: 0
/sys/module/radeon/parameters/aspm: -1
/sys/module/radeon/parameters/audio: 0
/sys/module/radeon/parameters/auxch: -1
/sys/module/radeon/parameters/backlight: -1
/sys/module/radeon/parameters/bapm: -1
/sys/module/radeon/parameters/benchmark: 0
/sys/module/radeon/parameters/connector_table: 0
/sys/module/radeon/parameters/deep_color: 0
/sys/module/radeon/parameters/disp_priority: 0
/sys/module/radeon/parameters/dpm: -1
/sys/module/radeon/parameters/dynclks: -1
/sys/module/radeon/parameters/fastfb: 0
/sys/module/radeon/parameters/gartsize: 1024
/sys/module/radeon/parameters/hard_reset: 0
/sys/module/radeon/parameters/hw_i2c: 0
/sys/module/radeon/parameters/lockup_timeout: 10000
/sys/module/radeon/parameters/modeset: 1
/sys/module/radeon/parameters/msi: -1
/sys/module/radeon/parameters/mst: 0
/sys/module/radeon/parameters/no_wb: 0
/sys/module/radeon/parameters/pcie_gen2: -1
/sys/module/radeon/parameters/r4xx_atom: 0
/sys/module/radeon/parameters/runpm: -1
/sys/module/radeon/parameters/test: 0
/sys/module/radeon/parameters/tv: 0
/sys/module/radeon/parameters/use_pflipirq: 2
/sys/module/radeon/parameters/vm_block_size: 12
/sys/module/radeon/parameters/vm_size: 8
/sys/module/radeon/parameters/vramlimit: 0

# cat /proc/cmdline
BOOT_IMAGE=/boot/vmlinuz-4.4.3-300.fc23.x86_64 root=UUID=03ee98ed-d998-4518-b216-b77822a9319b ro quiet radeon.audio=0 radeon.tv=0 audit=0 selinux=0

# cat /proc/version
Linux version 4.4.3-300.fc23.x86_64 (mockbuild@bkernel01.phx2.fedoraproject.org) (gcc version 5.3.1 20151207 (Red Hat 5.3.1-2) (GCC) ) #1 SMP Fri Feb 26 18:45:40 UTC 2016
Comment 5 Steve 2016-03-05 04:37:26 UTC
Further digging in this BZ seems to show this as a similar problem to:

/sys/class/drm/card0/device $ cat power_dpm_force_performance_level

/sys/class/drm/card0/device $ echo low > power_dpm_force_performance_level
-bash: echo: write error: Invalid argument

/sys/class/drm/card0/device $ cat power_dpm_force_performance_level

/sys/class/drm/card0/device $ echo high > power_dpm_force_performance_level
-bash: echo: write error: Invalid argument

/sys/class/drm/card0/device $ echo auto > power_dpm_force_performance_level
-bash: echo: write error: Invalid argument

Video card is:
$ lspci -v -s 03:00.0
03:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Barts XT [Radeon HD 6870] (prog-if 00 [VGA controller])
        Subsystem: Advanced Micro Devices, Inc. [AMD/ATI] Device 00d0
        Flags: bus master, fast devsel, latency 0, IRQ 37
        Memory at d0000000 (64-bit, prefetchable) [size=256M]
        Memory at fbcc0000 (64-bit, non-prefetchable) [size=128K]
        I/O ports at d000 [size=256]
        Expansion ROM at fbca0000 [disabled] [size=128K]
        Capabilities: [50] Power Management version 3
        Capabilities: [58] Express Legacy Endpoint, MSI 00
        Capabilities: [a0] MSI: Enable+ Count=1/1 Maskable- 64bit+
        Capabilities: [100] Vendor Specific Information: ID=0001 Rev=1 Len=010 <?>
        Capabilities: [150] Advanced Error Reporting
        Kernel driver in use: radeon
        Kernel modules: radeon
Comment 6 Martin Peres 2019-11-19 09:13:28 UTC
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