drm/ttm: fix the tt_populated check in ttm_tt_destroy()

After a vmalloc failure in ttm_dma_tt_alloc_page_directory(),
ttm_dma_tt_init() will call ttm_tt_destroy() to cleanup, and end up
inside the driver's unpopulate() hook when populate() has never yet
been called.

On nouveau, the first issue to be hit because of this is that
dma_address[] may be a NULL pointer.  After working around this,
ttm_pool_unpopulate() may potentially hit the same issue with
the pages[] array.

It seems to make more sense to avoid calling unpopulate on already
unpopulated TTMs than to add checks to all the implementations.

Signed-off-by: Ben Skeggs <[email protected]>
Reviewed-by: Thomas Hellstrom <[email protected]>
Cc: [email protected]
Cc: Jerome Glisse <[email protected]>
Signed-off-by: Dave Airlie <[email protected]>

0 files changed, 0 insertions, 0 deletions