[Bug 207183] New: radeon.dpm=1 with second monitor runs hot

[Bug 207183] New: radeon.dpm=1 with second monitor runs hot

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=207183

            Bug ID: 207183
           Summary: radeon.dpm=1 with second monitor runs hot
           Product: Drivers
           Version: 2.5
    Kernel Version: 5.3.18
          Hardware: x86-64
                OS: Linux
              Tree: Mainline
            Status: NEW
          Severity: normal
          Priority: P1
         Component: Video(DRI - non Intel)
          Assignee: drivers_video-dri@kernel-bugs.osdl.org
          Reporter: ehuels@gmail.com
        Regression: No

Created attachment 288315
  --> https://bugzilla.kernel.org/attachment.cgi?id=288315&action=edit
dmesg | grep -iE "drm|radeon"

for a long time, I've been searching for the reason why my card was running
fans high on Linux. (It started after a kernel update; don't know which one --
years ago) While at the time, I ran Windows on the same laptop every now and
then, it would work correctly.

My card reports `lspci | grep VGA`:

01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Venus
XT [Radeon HD 8870M / R9 M270X/M370X]


Without radeon.dpm or with radeon.dpm=1, the card runs hot: within minutes fans
will run at 3300+ RPM keeping the card barely below 66 degC. Note that
`radeontop` reports an `Graphics pipe` of 0.00% most of the time.

After discovery of the setting radeon.dpm yesterday, after a few failed trials
to set the setting to '1', I set `radeon.dpm=0`. After letting the PC cool down
(turned off) and starting again, the PC ran 10 minutes without fans and is
running at 53 degC with fans running at 2100 RPM.

-- 
You are receiving this mail because:
You are watching the assignee of the bug.
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

[Bug 207183] radeon.dpm=1 with second monitor runs hot

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=207183

--- Comment #1 from Erik Huelsmann (ehuels@gmail.com) ---
Note that the system doesn't exhibit this problem when only a single monitor is
attached. Monitor output in use: HDMI.

-- 
You are receiving this mail because:
You are watching the assignee of the bug.
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

[Bug 207183] radeon.dpm=1 with second monitor runs hot

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=207183

Alex Deucher (alexdeucher@gmail.com) changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |alexdeucher@gmail.com

--- Comment #2 from Alex Deucher (alexdeucher@gmail.com) ---
Note that the memory clock runs at high when multiple monitors are attached
because changing the memory clock has to happen during vblank time to avoid
glitches on the screen and with multiple monitors that is not aligned.

-- 
You are receiving this mail because:
You are watching the assignee of the bug.
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

[Bug 207183] radeon.dpm=1 with second monitor runs hot

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=207183

--- Comment #3 from Erik Huelsmann (ehuels@gmail.com) ---
Thanks for commenting. Does 'radeon.dpm=0' suppress that? I'm not having issues
when I set that parameter on the kernel command line.

-- 
You are receiving this mail because:
You are watching the assignee of the bug.
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

[Bug 207183] radeon.dpm=1 with second monitor runs hot

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=207183

--- Comment #4 from Alex Deucher (alexdeucher@gmail.com) ---
(In reply to Erik Huelsmann from comment #3)
> Thanks for commenting. Does 'radeon.dpm=0' suppress that? I'm not having
> issues when I set that parameter on the kernel command line.

That leave the GPU with the boot up clocks which are low.

-- 
You are receiving this mail because:
You are watching the assignee of the bug.
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

[Bug 207183] radeon.dpm=1 with second monitor runs hot

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=207183

--- Comment #5 from Erik Huelsmann (ehuels@gmail.com) ---
Is the fact that it's apparently not possible to switch the memory clock with 2
monitors attached a design error in the hardware? Unfortunately, I don't have
the Windows setup anymore to investigate it.
I'm extremely happy with my 'radeon.dpm=0' setup, because I'm only doing
text-editing, programming and web browsing.

As I understand it, it's a choice where you have to run a high clock
continually or cause possible on-screen glitches? That's too bad. I personally
wouldn't mind a small flicker if that would help the noise of my laptop, but I
do understand others may make other choices here.

-- 
You are receiving this mail because:
You are watching the assignee of the bug.
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

[Bug 207183] radeon.dpm=1 with second monitor runs hot

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=207183

--- Comment #6 from Alex Deucher (alexdeucher@gmail.com) ---
(In reply to Erik Huelsmann from comment #5)
> Is the fact that it's apparently not possible to switch the memory clock
> with 2 monitors attached a design error in the hardware? Unfortunately, I
> don't have the Windows setup anymore to investigate it.
> I'm extremely happy with my 'radeon.dpm=0' setup, because I'm only doing
> text-editing, programming and web browsing.
> 

The GPU dynamically changes the memory and gfx engine clocks at runtime based
on GPU load.  Unfortunately if changed the memory clock dynamically you'd see
flickering almost every frame if the GPU load changed.

You can manually force the clocks low or high via sysfs (as root):

force clocks low:
echo low > /sys/class/drm/card0/device/power_dpm_force_performance_level
force clocks high:
echo high > /sys/class/drm/card0/device/power_dpm_force_performance_level
dynamic:
echo auto > /sys/class/drm/card0/device/power_dpm_force_performance_level

-- 
You are receiving this mail because:
You are watching the assignee of the bug.
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel