unparseable, undocumented /sys/class/drm/.../pstate

Pavel Machek
2014-06-21T18:02:05Z

Hi!

AFAICT, pstate file will contain something like

07: core 100 MHz memory 123 MHz *
08: core 100-200 MHz memory 123 MHz

...which does not look exactly like one-value-per-file, and I'm pretty
sure userspace will get it wrong if it tries to parse it. Plus, I
don't see required documentation in Documentation/ABI.

Should we disable it for now, so that userspace does not start
depending on it and we'll not have to maintain it forever?

I guess better interface would be something like

pstate/07/core_clock_min
core_clock_max
memory_clock_min
memory_clock_max

and then pstate/active containing just the number of active state?

Thanks,
Pavel

PS: I have no nvidia, got the news at

http://www.phoronix.com/scan.php?page=article&item=nouveau_try_linux316&num=2
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