tree 63289e17f9c1adfe8fa2067b6605e28f38a7a264
parent 0b37a9a9ebdf47dc9d5290a1c69bd944dde5cc15
author Ville Syrjälä <ville.syrjala@linux.intel.com> 1426879688 +0200
committer Daniel Vetter <daniel.vetter@ffwll.ch> 1427103016 +0100

drm/i915: Use usleep_range() in wait_for()

msleep() can sleep for way too long, so switch wait_for() to use
usleep_range() instead. Following a totally unscientific method
I just picked the range as W-2W.

This cuts the i915 init time on my BSW to almost half:
- initcall i915_init+0x0/0xa8 [i915] returned 0 after 419977 usecs
+ initcall i915_init+0x0/0xa8 [i915] returned 0 after 238419 usecs

Note that I didn't perform any other benchmarks on this so far.

Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>