radv: Flush before copying with PKT3_WRITE_DATA in CmdUpdateBuffer

Need to flush before updating the buffer to ensure that the copy is
ordered after previous accesses (assuming the app has performed the
appropriate barriers).

This fixes potential issues due to draws prior to an update reading
the new buffer content, despite having the necessary barriers between
them.

Signed-off-by: Alex Smith <asmith@feralinteractive.com>
Cc: 17.0 <mesa-stable@lists.freedesktop.org>
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Reviewed-by: Dave Airlie <airlied@redhat.com>
(cherry picked from commit e0cc32b85bd8cf5c2202037838a208983e2d793a)
1 file changed