tree 8bbb47d8916e9396575ffa4e4743a64c4a6b956f
parent 6cd34b10cd642c15a8e4b2ed5fc4815c12c41d52
author Chris Wilson <chris@chris-wilson.co.uk> 1565353913 +0100
committer Chris Wilson <chris@chris-wilson.co.uk> 1565356011 +0100

drm/i915: Check for a second VCS engine more carefully

To use the legacy BSD selector, you must have a second VCS engine, or
else the ABI simply maps the request for another engine onto VCS0.
However, we only checked a single VCS1 location and overlooking the
possibility of a sparse VCS set being mapped to the dense ABI.

v2: num_vcs_engines() turns out to be reusable and futureproof it so we
never have to worry about this silly bit of ABI again!

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190809123153.20574-1-chris@chris-wilson.co.uk