On Thu, Jun 19, 2014 at 3:10 PM, Chris Healy <[email protected]> wrote:
> Hi Robert, > > This information is helpful. I am able to query the frequencies as you > mentioned. My primary interest though is in getting support added to > intel_gpu_top. It seems to me that intel_gpu_top has been coded to support > providing clock frequency data for a subset of Intel GPUs and that the > mobile Ivy Bridge GT2 chipset is not supported. Would you agree with this? > That looks right, yep. > If so, I'd like to fix this but don't know where to look for the bit > descriptions for the necessary registers. Can you point me to the > appropriate document? > I'm afraid it looks like that the i915_debugfs.c code may be the best reference a.t.m; though maybe someone who's worked on that code (not me) can give you a better answer. That said though; it could make sense to update intel_gpu_top to query debugfs for this information anyway; considering that it's more up to date and that way the logic doesn't need to be duplicated. For example if you take a look at overlay/gpu-freq.c in the intel_gpu_tools repo it looks like there's already some precedent for doing just that. It also looks like the utility code in overlay/debugfs.c can be used to make sure debugfs is mounted. Sorry I couldn't point you at good documentation for this; but hopefully that's still of some help to you. -- Regards, Robert > Regards, > > Chris > > > On Tue, Jun 17, 2014 at 7:43 PM, Bragg, Robert <[email protected]> > wrote: > >> Hi Chris, >> >> You can query the nominal and maximum frequency of your GPU via debugfs, >> in case that is good enough for your needs. Depending on what kernel >> version you have you can try to cat >> /sys/kernel/debug/dri/0/i915_cur_delayinfo or with more recent versions, >> /sys/kernel/debug/dri/0/i915_frequency_info >> >> If you are curious about more details then it may be best to look at the >> drm driver code in >> drivers/gpu/drm/i915/i915_debugfs.c:i915_frequency_info(). >> >> -- >> Regards, >> Robert >> >> On Wed, Jun 18, 2014 at 1:55 AM, He, Shuang <[email protected]> wrote: >> >>> Hi, Chris >>> >>> Let’s put you to the correct Mailing list for this topic first >>> >>> >>> >>> Thanks >>> >>> --Shuang >>> >>> *From:* Chris Healy [mailto:[email protected]] >>> *Sent:* Wednesday, June 18, 2014 1:15 AM >>> *To:* Eric Anholt; He, Shuang >>> *Subject:* intel_gpu_top missing clocks >>> >>> >>> >>> Eric, Shuang, >>> >>> I couldn't find an appropriate mailing list to report this on, so I'm >>> mailing the two of you as you've both touched the clock code in >>> intel_gpu_top. >>> >>> I'm running an Ivy Bridge Mobile chipset and trying to use intel_gpu_top >>> and intel_stepping to see the GPU clock frequencies. In both cases, the >>> clocks are "unknown". >>> >>> When I look at the code, it seems that there's just no code path to >>> handle this devid, though I'm not sure as I'm not very good at >>> understanding code. I see in intel_chipset.h that device id 0x0166 = >>> PCI_CHIP_IVYBRIDGE_M_GT2 and that none of the "if's" in print_clock_info >>> ultimately point to this device type. >>> >>> Do either of you know why this would be? Is it just a case of coding >>> for the majority of chipset configurations? >>> >>> If it's just the case of it not yet being handled, I'd be open to trying >>> to add support for it if you could point me to the necessary chip >>> documentation. >>> >>> Regards, >>> >>> Chris >>> >>> _______________________________________________ >>> Intel-gfx mailing list >>> [email protected] >>> http://lists.freedesktop.org/mailman/listinfo/intel-gfx >>> >>> >> >
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