drm/i915: use cpu_relax() in wait_for_atomic
authorBen Widawsky <ben@bwidawsk.net>
Sun, 2 Sep 2012 05:59:48 +0000 (22:59 -0700)
committerDaniel Vetter <daniel.vetter@ffwll.ch>
Mon, 3 Sep 2012 08:21:29 +0000 (10:21 +0200)
commit0cc2764cc4a4bd73df55f8893c871778cf7ddd0f
treef5f749fe2dcfab4801cfa00266c0bfbd36273ffd
parentb67a4376d53e1ae6eaef05389cfd0e6e5b7097db
drm/i915: use cpu_relax() in wait_for_atomic

As part of the advice given to us from the hardware designers regarding
the maximum wait time on the forcewake handshake we need to move from us
granularity to ms granularity. In earlier patches to do this, Jani
noticed that wait_for_us was properly converted to use cpu_relax(), but
wait_for was not.

The issue has existed since the introduction of the macro:
commit 913d8d110078788c14812dce8bb62c37946821d2
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Sat Aug 7 11:01:35 2010 +0100

    drm/i915: Ensure that while(INREG()) are bounded (v2)

CC: Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: Chris Wilson <chris@chris-wilson.oc.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
drivers/gpu/drm/i915/intel_drv.h