RADEON / DPM: GPU cannot properly up-clock

[Joshua C.]

2013/6/28 Joshua C. <joshuacov at gmail.com>:
> 2013/6/27 Alex Deucher <alexdeucher at gmail.com>:
>> On Wed, Jun 26, 2013 at 4:57 PM, Joshua C. <joshuacov at gmail.com> wrote:
>>> 2013/6/26 Deucher, Alexander <Alexander.Deucher at amd.com>:
>>>>
>>>>
>>>>> -----Original Message-----
>>>>> From: Joshua C. [mailto:joshuacov at gmail.com]
>>>>> Sent: Wednesday, June 26, 2013 1:52 PM
>>>>> To: dri-devel at lists.freedesktop.org
>>>>> Cc: Deucher, Alexander
>>>>> Subject: RADEON / DPM: GPU cannot properly up-clock
>>>>>
>>>>> First of all thank you guys for pushing this out! Great work!
>>>>>
>>>>> I tried the latest code in drm-next-3.11-wip (up to commit
>>>>> b3c1e0c3ba885db44 "drm/radeon: fix endian issues in atombios dpm
>>>>> code") in connection with the latest radeon_ucode (latest update on
>>>>> 2013-06-26). I also reintroduced the debugfs info so that I can better
>>>>> observe the gpu-settings. For this I put back the following patch:
>>>>>
>>>>> diff --git a/drivers/gpu/drm/radeon/radeon_pm.c
>>>>> b/drivers/gpu/drm/radeon/radeon_pm.c
>>>>> index 7ba5d6f..9367234 100644
>>>>> --- a/drivers/gpu/drm/radeon/radeon_pm.c
>>>>> +++ b/drivers/gpu/drm/radeon/radeon_pm.c
>>>>> @@ -1066,6 +1066,11 @@ static int radeon_pm_init_dpm(struct
>>>>> radeon_device *rdev)
>>>>>          ret = device_create_file(rdev->dev, &dev_attr_power_method);
>>>>>          if (ret)
>>>>>              DRM_ERROR("failed to create device file for power method\n");
>>>>> +
>>>>> +        if (radeon_debugfs_pm_init(rdev)) {
>>>>> +            DRM_ERROR("Failed to register debugfs file for PM!\n");
>>>>> +        }
>>>>> +
>>>>>          DRM_INFO("radeon: dpm initialized\n");
>>>>>      }
>>>>>
>>>>> --
>>>>> 1.8.2.1
>>>>
>>>> I removed that code for a reason when DPM is active.  With DPM the hardware changes the power state dynamically internally so that old debugging information is completely irrelevant when DPM is active.
>>>>
>>>> Alex
>>>>
>>>>
>>>
>>> I see. Do you have any idea why I see those delays when playing a
>>> HD-movie? They do not appear when switching to dynpm. I use the latest
>>> llvm(3.4svn), libdrm(2.4.45), mesa(9.2.0 devel), xserver(1.14.99.0),
>>> xf86-video-ati(deve) - all fetched from git as of 2013-06-26.
>>
>> What type of movie is it and what are you using to decode the movie? UVD?  CPU?
>>
>> Alex
>
> Here is an example of the information from one of the films:
>
> Stream 0
> Type: Video
> Codec: H264 - MPEG-4 AVC (part 10) (avc1)
> Lang: English
> Res: 1280x544
> Bitrate: 23.976215
> Format: Planar 4:2:0 YVU
> Stream 1
> Type: Audio
> Codec: DTS Audio (dts )
> Lang: English
> Channels: 3F2R/LFE
> Freq: 48000 Hz
> Bitrate: 1536 kb/s
>
> I recompiled the whole videostack (mesa, llvm, drm, xserver,
> xf86-video-ati, vdpau - all from git) against the patched kernel and
> can say that currently there are no visible regressions. The "slow
> motion" is almost gone. However I still see it in some frames but I'm
> not sure if this is a kernel-part-problem or just a mesa-problem.
>
> However I observe the following:
>
> Under windows: smooth play, temps in idle: 34-35C, cpu-usage: up to 5%
> on all cores on a 4-core cpu, temps when playing the film: up to 42C,
> cpu-usage: up to 5% on all 4 cores
>
> Under linux (updated as described above): some discrepences (those
> happen pretty rarely, though), temps in idle: 34-36C, cpu-usage: up to
> 5%, temps when playing the film: no more than 37C, cpu-usage: one core
> is constantly spiking up to 40% the other 3 stay below 7%.
>
> When looking through the dmesg I cannot see that dpm is changing the
> power state to "uvd". This makes me believe that I'm maybe using a
> cpu-decode rather then the dedicated uvd. The gpu-temps are also
> staying surpricingly low comapred to windows...
>
> --
> --joshua


With the latest git 7982128c3d447df27db963af67bc6b8dc7efb1de
"drm/radeon/dpm: add debugfs support for SI" from
git://people.freedesktop.org/~agd5f/linux drm-next-3.11 everything
works fine here (on TURKS). Under Linux I get the same temps as under
windows. No more tearing when watching videos. The GPU re-clocks as
desired...


--
--joshua