[Intel-gfx] [PATCH] allow 945 to control self refresh automatically

[Alexander Lam]

Using 2.6.35.7 (this patch is against drm-intel-next 7dcd249, but untested),
I changed 945's self refresh to work without the need for the driver to
enable/disable self refresh manually based on the idle state of the gpu.
This is much better than enabling/disabling self refresh for various
reasons, including staying in a lower power state for more time and
avoiding the need for cpu cycles.

Something must have been fixed in the driver between the initial
implementation of 945 self refresh and now.
(maybe 944001201ca0196bcdb088129e5866a9f379d08c: drm/i915: enable low
power render writes on GEN3 hardware?)

This patch probably doesn't cover all cases concerning if SR should
be enabled/disabled, not to mention doing things in the wrong order or
in the wrong place.

It only works with printk statements or replacing the printk's
with DRM_DEBUG and turning drm debugging on (I don't understand what is
going on there...).
---
 drivers/gpu/drm/i915/intel_display.c |   37 ++++++++++-----------------------
 1 files changed, 11 insertions(+), 26 deletions(-)

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