<html> <head> <base href="https://bugs.freedesktop.org/" /> </head> <body> <div> <a class="bz_bug_link bz_status_NEEDINFO " title="NEEDINFO - constant fps drops with Intel and Radeon" href="https://bugs.freedesktop.org/show_bug.cgi?id=87886#c27">Comment # 27</a> on <a class="bz_bug_link bz_status_NEEDINFO " title="NEEDINFO - constant fps drops with Intel and Radeon" href="https://bugs.freedesktop.org/show_bug.cgi?id=87886">bug 87886</a> from <a class="email" href="mailto:stephane.travostino@gmail.com" title="Stéphane Travostino <stephane.travostino@gmail.com>"> Stéphane Travostino</a> <pre>(In reply to Eero Tamminen from <a href="show_bug.cgi?id=87886#c26">comment #26</a>) > as root, mount debugfs and monitor CAGF (actual GPU frequency) value from > "/sys/kernel/debug/dri/0/i915_frequency_info", or if you have older kernel > from "/sys/kernel/debug/dri/0/i915_cur_delayinfo" Does it keep up, or go > down when you get FPS drop? > > (If it goes down, this seems like kernel power management issue.) Good call! Watching i915_frequency_info while running glxgears on Intel, I see it starts at 1100 MHz and after a few seconds it starts to drop to 650 MHz and up again, repeatedly. Frequency changes collerate with FPS changes in glxgears, so yeah, it seems it is a kernel pm issue. I tried booting up with i915.powersave=0 i915.enable_rc6=0, also tried disabling Runtime PM on the Intel card via powertop but I can't find a way to force the frequency to max values to be 100% sure it's frequency switching related. Any idea where to go from there?</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the assignee for the bug.</li> </ul> </body> </html>