Created attachment 130517 [details] dmesg ==Bug detailed description== -------------------------------------------------- cdclock frequency is always the same, it does not matter if reslution is changed on displays ==Steps to reproduce== -------------------------------------------------- 1. set a 4k resolution 2. cat /sys/kernel/debug/dri/0/i915_frequency_info |grep "Current CD clock frequency:" 3. set a HD resolution 4. cat /sys/kernel/debug/dri/0/i915_frequency_info |grep "Current CD clock frequency:" ==Actual results== -------------------------------------------------- cdclock frequency is always the same (316800 kHz) , it does not matter if reslution is changed on displays ==Expected results== -------------------------------------------------- cdclock frequency must change according to resolution set on display ==Hardware configuration== -------------------------------------------------- CPU Name : Genuine Intel(R) CPU @ 1.10GHz (family: 6, model: 122) 4 cores Graphic: Intel Corporation Device 3184 (rev 01) prog-if 00 VGA controller RVP SKU : GLK RVP1 SOC : GML A1 Soc QDF : Ql9R Reworks : F23 ==Software configuration== -------------------------------------------------- kernel version : 4.11.0-rc4-drm-tip-ww14-commit-dabd992+ architecture : x86_64 os version : Ubuntu 16.10 os codename : yakkety [sudo] password for gfx: kernel driver : i915 bios revision : 36.51 ksc : 1.13 modesetting : modesetting_drv.so xorg-xserver : 1.18.4 libdrm : 2.4.75 vaapi (intel-driver) : Intel i965 driver for Intel(R) Geminilake - 1.8.1.pre1 (1.7.3-358-g228e4fc) cairo : 1.15.5 xserver : X.Org X Server 1.19.99.1 intel-gpu-tools (tag) : intel-gpu-tools-1.18-40-g429dd43 intel-gpu-tools (commit) : 429dd43 ==kernel configuration== -------------------------------------------------- commit dabd992961047cf26698036f563aa86a083284ac Author: Jani Nikula <jani.nikula@intel.com> Date: Tue Mar 28 18:26:27 2017 +0300 drm-tip: 2017y-03m-28d-15h-25m-54s UTC integration manifest Kernel version : 4.11.0-rc4-dabd992 Architecture : source amd64 all
The culprits are likely these two commits: commit 8cbeb06dc6b584009d7492c667a3c9a4b96cdefa Author: Pandiyan, Dhinakaran <dhinakaran.pandiyan@intel.com> Date: Tue Mar 14 15:45:56 2017 -0700 drm/i915: Implement cdclk restrictions based on Azalia BCLK commit 78cfa580f81e69857815c59c8908aee454726da1 Author: Pandiyan, Dhinakaran <dhinakaran.pandiyan@intel.com> Date: Tue Mar 7 16:12:51 2017 -0800 drm/i915/glk: Apply cdclk workaround for DP audio
Updated to highest/blocker due to the impact on CDCLK Alpha feature
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, 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.
This isn't a bug IMO, should we close this?
Priority decreased, test is planned again ww15
It was tested again using new requirements. So closed.
(In reply to Dhinakaran Pandiyan from comment #3) > 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.
Use of freedesktop.org services, including Bugzilla, is subject to our Code of Conduct. How we collect and use information is described in our Privacy Policy.