On Thu, Jun 19, 2014 at 09:33:44PM +0100, Bragg, Robert wrote: > On Thu, Jun 19, 2014 at 3:10 PM, Chris Healy <[1]cphealy@xxxxxxxxx> > 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. intel_gpu_top was designed and developed before we had variable GPU frequencies and before we had either the sysfs or debugfs interace. >  > > 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. Please do not use debugfs. Generally this is not the interface to write a tool against. The sysfs interface is a stable interface, and that should always be used. tests/pm_rps.c already loads and reads/writes this interface. Copy that code to print_clock_info () with the appropriate if (have_sysfs(...)) or whatever you want. BTW pm_rps has gotten very complex in the last few months. I would recommend using the git history to find the initial commit for this task. > -- > Regards, > Robert > > Regards, > Chris > > On Tue, Jun 17, 2014 at 7:43 PM, Bragg, Robert > <[2]robert.bragg@xxxxxxxxx> 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 <[3]shuang.he@xxxxxxxxx> > wrote: > > Hi, Chris > >         Letâs put you to the correct Mailing list for this > topic first > >  > > Thanks > >         --Shuang > > From: Chris Healy [mailto:[4]cphealy@xxxxxxxxx] > 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 > [5]Intel-gfx@xxxxxxxxxxxxxxxxxxxxx > [6]http://lists.freedesktop.org/mailman/listinfo/intel-gfx > > References > > 1. mailto:cphealy@xxxxxxxxx > 2. mailto:robert.bragg@xxxxxxxxx > 3. mailto:shuang.he@xxxxxxxxx > 4. mailto:cphealy@xxxxxxxxx > 5. mailto:Intel-gfx@xxxxxxxxxxxxxxxxxxxxx > 6. http://lists.freedesktop.org/mailman/listinfo/intel-gfx > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@xxxxxxxxxxxxxxxxxxxxx > http://lists.freedesktop.org/mailman/listinfo/intel-gfx -- Ben Widawsky, Intel Open Source Technology Center _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
