Bug 111047 - On IceLake machine GPU can't enter DC6
Summary: On IceLake machine GPU can't enter DC6
Status: RESOLVED INVALID
Alias: None
Product: DRI
Classification: Unclassified
Component: DRM/Intel (show other bugs)
Version: unspecified
Hardware: Other All
: high critical
Assignee: Intel GFX Bugs mailing list
QA Contact: Intel GFX Bugs mailing list
URL:
Whiteboard: Triaged
Keywords:
Depends on:
Blocks:
 
Reported: 2019-07-03 08:08 UTC by AceLan Kao
Modified: 2019-07-08 08:04 UTC (History)
2 users (show)

See Also:
i915 platform: ICL
i915 features: power/runtime PM


Attachments
kern.log with drm.debug=0x1e (610.98 KB, text/x-log)
2019-07-03 08:08 UTC, AceLan Kao
no flags Details

Description AceLan Kao 2019-07-03 08:08:18 UTC
Created attachment 144690 [details]
kern.log with drm.debug=0x1e

We're working on IceLake platforms, but GPU can't enter DC6.
The DC5 count is increasing while the screen dim.

$ sudo cat /sys/kernel/debug/dri/0/i915_dmc_info
fw loaded: yes
path: i915/icl_dmc_ver1_07.bin
version: 1.7
DC3 -> DC5 count: 30
DC5 -> DC6 count: 0
program base: 0x0b004040
ssp base: 0x00006fc0
htp: 0x00a40088
Comment 1 Cooper Chiou 2019-07-03 08:46:20 UTC
From drm log, I can see DC6 is enabled.

Jul  3 16:01:45 u-xxxx kernel: [   17.967382] [drm:edp_panel_vdd_off_sync [i915]] Turning eDP port A VDD off
Jul  3 16:01:45 u-xxxx kernel: [   17.967519] [drm:edp_panel_vdd_off_sync [i915]] PP_STATUS: 0x80000008 PP_CONTROL: 0x00000067
Jul  3 16:01:45 u-xxxx kernel: [   17.967563] [drm:intel_power_well_disable [i915]] disabling DC off
Jul  3 16:01:45 u-xxxx kernel: [   17.967610] [drm:skl_enable_dc6 [i915]] Enabling DC6
Jul  3 16:01:45 u-xxxx kernel: [   17.967650] [drm:gen9_set_dc_state [i915]] Setting DC state from 00 to 02
Comment 2 qwang13 2019-07-03 10:56:46 UTC
From Imre Deak

Not any problem found in the log, DC6 gets enabled by the driver.

Question:
a.	does the Loki MLK eDP panel has PSR support?
b.	Check if you get DC5/6 transitions on Loki MLK if you disable the display?
disable display; and then "cat /sys/kernel/debug/dri/0/i915_dmc_info"
Comment 3 Lakshmi 2019-07-04 06:27:31 UTC
(In reply to qwang13 from comment #2)
> From Imre Deak
> 
> Not any problem found in the log, DC6 gets enabled by the driver.
> 
> Question:
> a.	does the Loki MLK eDP panel has PSR support?
> b.	Check if you get DC5/6 transitions on Loki MLK if you disable the display?
> disable display; and then "cat /sys/kernel/debug/dri/0/i915_dmc_info"

Imre, any comments?
Comment 4 Imre Deak 2019-07-04 10:12:55 UTC
(In reply to Lakshmi from comment #3)
> (In reply to qwang13 from comment #2)
> > From Imre Deak
> > 
> > Not any problem found in the log, DC6 gets enabled by the driver.
> > 
> > Question:
> > a.	does the Loki MLK eDP panel has PSR support?
> > b.	Check if you get DC5/6 transitions on Loki MLK if you disable the display?
> > disable display; and then "cat /sys/kernel/debug/dri/0/i915_dmc_info"
> 
> Imre, any comments?

I can't see any issues in the log, the driver enables DC5/6. I think the eDP panel doesn't support PSR, which would block these states. Let's wait for the reporter to confirm that.
Comment 5 AceLan Kao 2019-07-08 08:04:22 UTC
It's a BIOS issue, and we can enter DC5/DC6 and PC10 now.
Thanks.


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