tree 240106fe1072aeae2917c3c3c5fca83ba4f8a641
parent 1e99cfa8de0f0879091e33cd65fd60418d006ad9
author Dave Airlie <airlied@redhat.com> 1407306381 +1000
committer Dave Airlie <airlied@redhat.com> 1413175253 +1000

drm/mst: rework payload table allocation to conform better.

The old code has problems with the Dell MST monitors due to some
assumptions I made that weren't true.

I initially thought the Virtual Channel Payload IDs had to be in
the DPCD table in ascending order, however it appears that assumption
is bogus.

The old code also assumed it was possible to insert a member
into the table and it would move other members up, like it does
when you remove table entries, however reality has shown this
isn't true.

So the new code allocates VCPIs separate from entries in the payload
tracking table, and when we remove an entry from the DPCD table,
I shuffle the tracking payload entries around in the struct.

This appears to make VT switch more robust (still not perfect)
with an MST enabled Dell monitor.

Signed-off-by: Dave Airlie <airlied@redhat.com>