[Intel-gfx] [PATCH] drm/i915: Try enabling RC6 by default (again)

[Ted Phelps]

Keith Packard writes:
> Jesse Barnes and I found a couple of issues where incorrect mode
> setting would cause problems with RC6 enabled. We're hopeful that
> fixing those will resolve the outstanding issues with a few machines
> that had trouble before 3.0 with rc6.

Thanks for continuing to bash on this, but I'm afraid I'm still having
issues.

I saw a bunch of stack traces like the one below, alternating between
ring_put and ring_get, before the GPU was declared wedged.

------------[ cut here ]------------
WARNING: at drivers/gpu/drm/i915/i915_drv.c:387 __gen6_gt_wait_for_fifo+0x8a/0x90 [i915]()
Hardware name:         
Modules linked in: tun ohci_hcd i915 fbcon font bitblit softcursor drm_kms_helper drm pl2303 usbserial e1000e cfbcopyarea video cfbimgblt cfbfillrect processor button xfs
Pid: 2045, comm: X Not tainted 3.0.0-00175-g07b7ddd #262
Call Trace:
 [<ffffffff81047dca>] warn_slowpath_common+0x7a/0xb0
 [<ffffffff81047e15>] warn_slowpath_null+0x15/0x20
 [<ffffffffa019573a>] __gen6_gt_wait_for_fifo+0x8a/0x90 [i915]
 [<ffffffffa01eb7a3>] gen6_ring_put_irq+0xb3/0x150 [i915]
 [<ffffffffa01eb853>] blt_ring_put_irq+0x13/0x20 [i915]
 [<ffffffffa01b55b4>] i915_wait_request+0x1d4/0x710 [i915]
 [<ffffffff8106a0f0>] ? wake_up_bit+0x40/0x40
 [<ffffffffa01b5b22>] i915_gem_object_wait_rendering+0x32/0x40 [i915]
 [<ffffffffa01b78b8>] i915_gem_object_set_to_gtt_domain+0xc8/0x160 [i915]
 [<ffffffffa01b7a09>] i915_gem_set_domain_ioctl+0xb9/0x100 [i915]
 [<ffffffffa0113514>] drm_ioctl+0x3d4/0x4c0 [drm]
 [<ffffffffa01b7950>] ? i915_gem_object_set_to_gtt_domain+0x160/0x160 [i915]
 [<ffffffff81537169>] ? _raw_spin_unlock_irq+0x9/0x40
 [<ffffffff8100b654>] ? check_for_xstate+0x44/0xb0
 [<ffffffff81117037>] do_vfs_ioctl+0x97/0x5d0
 [<ffffffff8100234b>] ? sys_rt_sigreturn+0x1fb/0x210
 [<ffffffff81117601>] sys_ioctl+0x91/0xa0
 [<ffffffff8153dafb>] system_call_fastpath+0x16/0x1b
---[ end trace 070cd7741c91254d ]---
------------[ cut here ]------------

... lots of the above ...

[drm:i915_hangcheck_elapsed] *ERROR* Hangcheck timer elapsed... GPU hung
[drm] capturing error event; look for more information in /debug/dri/0/i915_error_state
[drm:i915_wait_request] *ERROR* i915_wait_request returns -11 (awaiting 936788 at 936786, next 936789)
[drm:init_ring_common] *ERROR* render ring initialization failed ctl 00000000 head 00000000 tail 00000000 start 00000000
[drm:init_ring_common] *ERROR* gen6 bsd ring initialization failed ctl 00000000 head 00000000 tail 00000000 start 00000000
[drm:init_ring_common] *ERROR* blt ring initialization failed ctl 00000000 head 00000000 tail 00000000 start 00000000
[drm:i915_hangcheck_elapsed] *ERROR* Hangcheck timer elapsed... GPU hung
[drm:i915_wait_request] *ERROR* i915_wait_request returns -11 (awaiting 936792 at 936783, next 936793)
[drm:i915_reset] *ERROR* GPU hanging too fast, declaring wedged!
[drm:i915_reset] *ERROR* Failed to reset chip.


This is with mesa-7.11rc4, xf86-video-intel-2.15.0 and a Linux kernel
3.0.0-00175-g07b7ddd (head of keithp's drm-intel-next).

I'll attach the i915_error_state to bug #38567.

Cheers,
-Ted