Can you please attach the output from pm_pc8 from a working kernel?

My guess is that the test doesn't properly skip here and 3.14 likely gained pm counter support for bdw or something like this ...

Yes, It doesn't properly skip. 
output(42aa254c65f):
IGT-Version: 1.5-g42aa254 (x86_64) (Linux: 3.14.0-rc4_drm-intel-nightly_0dfe3c_20140303+ x86_64)
Runtime PM support: 0
PC8 residency support: 0
Test requirement not met in function setup_environment, file pm_pc8.c:766:
Last errno: 5, Input/output error
Test requirement: (!(has_runtime_pm || has_pc8))
Subtest debugfs-read: SKIP

That is expected. The "regression" is that I told IGT that Broadwell should have PC8 support. Then, when you ran the test, it detected we did not support runtime PM, so it tried to test everything by checking PC8 residencies, and failed, as expected.

Now that we merged runtime PM support for Broadwell, only the subtests with "pc8" on their names should fail.

I will remove the word "regression" form the title since the root cause is that we started running tests instead of skipping, and we shouldn't be skipping since we want PC8 support on BDW anyway.

This should be fixed now. Please re-open if you still see a problem.

Created attachment 100073 [details]
dmesg

Some subcases still fail.
# ./pm_rpm --run-subtest pc8-residency
IGT-Version: 1.6-ge4ba3b7 (x86_64) (Linux: 3.15.0-rc7_drm-intel-nightly_d13557_20140529+ x86_64)
Runtime PM support: 1
PC8 residency support: 1
Test assertion failure function pc8_residency_subtest, file pm_rpm.c:734:
Last errno: 2, No such file or directory
Failed assertion: pc8_plus_residency_changed(120)
Machine is not reaching PC8+ states, please check its configuration.
Subtest pc8-residency: FAIL

Hi

Please go to the BIOS, Intel Advanced Menu -> Power and Performance -> CPU Power Management Control -> Package C state Limit, then set it to "C10".

Then test this tree: http://cgit.freedesktop.org/~pzanoni/linux/log/?h=bdw-pc8-fixes . Don't forget to switch to the bdw-pc8-fixes branch.

Please also boot with drm.debug=0xe and send the dmesg output in case there's any problem.

Thanks,
Paulo

(In reply to comment #6)
> Hi
> 
> Please go to the BIOS, Intel Advanced Menu -> Power and Performance -> CPU
> Power Management Control -> Package C state Limit, then set it to "C10".
> 
> Then test this tree:
> http://cgit.freedesktop.org/~pzanoni/linux/log/?h=bdw-pc8-fixes . Don't
> forget to switch to the bdw-pc8-fixes branch.
> 
> Please also boot with drm.debug=0xe and send the dmesg output in case
> there's any problem.
> 
> Thanks,
> Paulo

It still fails.

output:
IGT-Version: 1.7-g7ef5372 (x86_64) (Linux: 3.16.0-rc2_kcloud_619f97_20140701+ x86_64)
Runtime PM support: 1
PC8 residency support: 1
Test assertion failure function pc8_residency_subtest, file pm_rpm.c:734:
Last errno: 2, No such file or directory
Failed assertion: pc8_plus_residency_changed(120)
Machine is not reaching PC8+ states, please check its configuration.
Subtest pc8-residency: FAIL

Created attachment 102041 [details]
dmesg(bdw-pc8-fixes branch)

Hi

Thanks for testing. I just updated the tree, including a patch that was missing. Can you please try again?

Also please disconnect all the USB devices before running the test. I see you have an USB mouse that keeps waking up the Kernel. And if you have wireless on the machine, please also disconnect it: you might want to physically remove the wireless device, if possible.

The BDW environment for PC8 testing should be the same as the HSW environment.

Thanks,
Paulo

Created attachment 102182 [details]
dmesg(commit 8eb06d)

IGT-Version: 1.7-g67e29a3 (x86_64) (Linux: 3.16.0-rc2_kcloud_8eb06d_20140703+ x86_64)
Runtime PM support: 1
PC8 residency support: 1
Test assertion failure function pc8_residency_subtest, file pm_rpm.c:734:
Last errno: 2, No such file or directory
Failed assertion: pc8_plus_residency_changed(120)
Machine is not reaching PC8+ states, please check its configuration.
Subtest pc8-residency: FAIL

(In reply to comment #10)
> Created attachment 102182 [details]
> dmesg(commit 8eb06d)
> 
> IGT-Version: 1.7-g67e29a3 (x86_64) (Linux:
> 3.16.0-rc2_kcloud_8eb06d_20140703+ x86_64)
> Runtime PM support: 1
> PC8 residency support: 1
> Test assertion failure function pc8_residency_subtest, file pm_rpm.c:734:
> Last errno: 2, No such file or directory
> Failed assertion: pc8_plus_residency_changed(120)
> Machine is not reaching PC8+ states, please check its configuration.
> Subtest pc8-residency: FAIL

It seems you didn't disconnect all your USB devices before running the test. I still see them in dmesg. Can you please redo the test as described in comment #9?

Created attachment 102227 [details]
dmesg

IGT-Version: 1.7-g67e29a3 (x86_64) (Linux: 3.16.0-rc2_kcloud_8eb06d_20140703+ x86_64)
Runtime PM support: 1
PC8 residency support: 1
Test assertion failure function pc8_residency_subtest, file pm_rpm.c:734:
Last errno: 2, No such file or directory
Failed assertion: pc8_plus_residency_changed(120)
Machine is not reaching PC8+ states, please check its configuration.
Subtest pc8-residency: FAIL

QA team checked another BDW-U system, and build kernel from Paulo's branch http://cgit.freedesktop.org/~pzanoni/linux/log/?h=bdw-pc8-fixes, we can successfully see system entry into PC8, passed IGT PC8 subtests:

[root@x-bdw02 tests]# ./pm_rpm --run-subtest pc8-residency
IGT-Version: 1.7-g8d60b82 (x86_64) (Linux: 3.16.0-rc2_kcloud_8eb06d_20140703+ x86_64)
Runtime PM support: 1
PC8 residency support: 1
Subtest pc8-residency: SUCCESS

[root@x-bdw02 tests]# ./pm_rpm --run-subtest modeset-pc8-residency-stress
IGT-Version: 1.7-g8d60b82 (x86_64) (Linux: 3.16.0-rc2_kcloud_8eb06d_20140703+ x86_64)
Runtime PM support: 1
PC8 residency support: 1
Subtest modeset-pc8-residency-stress: SUCCESS

[root@x-bdw02 tests]# ./pm_rpm --run-subtest gem-execbuf-stress-pc8
IGT-Version: 1.7-g8d60b82 (x86_64) (Linux: 3.16.0-rc2_kcloud_8eb06d_20140703+ x86_64)
Runtime PM support: 1
PC8 residency support: 1
Subtest gem-execbuf-stress-pc8: SUCCESS

Since the test passes on some of QA's machines and we believe our code is complete, I will close this as fixed. BDW machines that can't hit PC8 are probably either misconfigured, or have a too-old BIOS, or have a too-old processor.

If you think the bug is not fixed yet, please reopen.

Re-verified on another failed BDW unit: x-bdw01
Upgrade the BIOS to V86.R00 and change the internal display into eDP panel.
used Kernel is : Linux x-bdw01 3.16.0-rc6_drm-intel-nightly_e967a5_20140728+ #868 SMP Mon Jul 28 11:24:20 CST 2014 x86_64 x86_64 x86_64 GNU/Linux

pc8-residency and debugfs-read subtests all verified as PASS, log message show in below.
[root@x-bdw01 tests]# ./pm_rpm --run-subtest pc8-residency
IGT-Version: 1.7-gfcbc502 (x86_64) (Linux: 3.16.0-rc6_drm-intel-nightly_e967a5_20140728+ x86_64)
Runtime PM support: 1
PC8 residency support: 1
Subtest pc8-residency: SUCCESS
You have new mail in /var/spool/mail/root
[root@x-bdw01 tests]# ./pm_rpm --run-subtest debugfs-read
IGT-Version: 1.7-gfcbc502 (x86_64) (Linux: 3.16.0-rc6_drm-intel-nightly_e967a5_20140728+ x86_64)
Runtime PM support: 1
PC8 residency support: 1
Subtest debugfs-read: SUCCESS

Closing old verified.