linux/drivers/gpu
Daniel Vetter b7884eb45e drm/i915: hold forcewake around ring hw init
Empirical evidence suggests that we need to: On at least one ivb
machine when running the hangman i-g-t test, the rings don't properly
initialize properly - the RING_START registers seems to be stuck at
all zeros.

Holding forcewake around this register init sequences makes chip reset
reliable again. Note that this is not the first such issue:

commit f01db988ef
Author: Sean Paul <seanpaul@chromium.org>
Date:   Fri Mar 16 12:43:22 2012 -0400

    drm/i915: Add wait_for in init_ring_common

added delay loops to make RING_START and RING_CTL initialization
reliable on the blt ring at boot-up. So I guess it won't hurt if we do
this unconditionally for all force_wake needing gpus.

To avoid copy&pasting of the HAS_FORCE_WAKE check I've added a new
intel_info bit for that.

v2: Fixup missing commas in static struct and properly handling the
error case in init_ring_common, both noticed by Jani Nikula.

Cc: stable@vger.kernel.org
Reported-and-tested-by: Yang Guang <guang.a.yang@intel.com>
Reviewed-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=50522
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2012-06-04 20:25:29 +02:00
..
drm drm/i915: hold forcewake around ring hw init 2012-06-04 20:25:29 +02:00
stub i915: select VIDEO_OUTPUT_CONTROL for ACPI_VIDEO 2011-04-13 09:10:25 +10:00
vga vga_switcheroo: Add the support for audio clients 2012-05-13 11:27:21 +02:00
Makefile gpu: Add Intel GMA500(Poulsbo) Stub Driver 2010-10-26 11:00:13 +10:00