<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_CLOSED bz_closed" title="CLOSED NOTABUG - [GLK] cdclock frequency is always the same" href="https://bugs.freedesktop.org/show_bug.cgi?id=100439#c7">Comment # 7</a> on <a class="bz_bug_link bz_status_CLOSED bz_closed" title="CLOSED NOTABUG - [GLK] cdclock frequency is always the same" href="https://bugs.freedesktop.org/show_bug.cgi?id=100439">bug 100439</a> from <a class="email" href="mailto:abhijeet.kumar@intel.com" title="Abhijeet Kumar <abhijeet.kumar@intel.com>"> Abhijeet Kumar</a> <pre>(In reply to Dhinakaran Pandiyan from <a href="show_bug.cgi?id=100439#c3">comment #3</a>) > HDMI audio is being enabled, which restricts cdclk going lower than 2*Azalia > bclk (96 MHz by default). The choices for cdclk on GLK are 316.8 MHz, 158.4 > MHz and 79.2 MHz. So, the only value greater than 2*96 MHz is 316.8 MHz. > > From BSpec > "158.4 MHz CD (cannot be used when audio is enabled and Azalia BCLK is 96 > MHz) > 316.8 MHz CD > 79.2 MHz CD (exclusively for resolutions up to 1080p in low power single > pipe eDP/MIPI configurations, no audio support)" > > Not entirely sure what happens if we violate this restriction in practice, Adding my two cents to it. Due to violation I've seen igt tests@pm_rpm,kms@flip failing as HDA was not suspending. Test name kms_flip --run-subtest vblank-vs-modeset-rpm kms_flip --run-subtest vblank-vs-modeset-rpm-interruptible kms_flip --run-subtest vblank-vs-dpms-rpm kms_flip --run-subtest vblank-vs-dpms-rpm-interruptible pm_rpm --run-subtest basic-pci-d3-state pm_rpm --run-subtest basic-rte > but I think it makes sense to define a new API to get the actual Azalia bclk > from the audio driver and explore options to lower that.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the QA Contact for the bug.</li> <li>You are on the CC list for the bug.</li> </ul> </body> </html>