Make sure we have enough room for all the GR registers or we'll end up
clobbering the AR index register (which should actually be harmless
unless the BIOS is making an assumption about it).
On resume, if the interrupt state isn't restored correctly, we may end
up with a flood of unexpected or ill-timed interrupts, which could cause
the kernel to disable the interrupt or vblank events to happen at the
wrong time. So save/restore them properly.
There were two problems with the existing callback code: the vblank
enable callback happened multiple times per disable, making drivers more
complex than they had to be, and there was a race between the final
decrement of the vblank usage counter and the next enable call, which
could have resulted in a put->schedule disable->get->enable->disable
sequence, which would be bad.
So add a new vblank_enabled array to track vblank enable on per-pipe
basis, and add a lock to protect it along with the refcount +
enable/disable calls to fix the race.
sequence number may actually turn up before the corresponding fence
object has been queued on the ring.
Fence drivers can use this member to determine whether a
sequence number must be re-reported.
In hibernate, we may end up calling the VGA save regs function twice, so we
need to make sure it's idempotent. That means leaving ARX in index mode after
the first save operation. Fixes hibernate on 965.
We need to return an accurate vblank count to the callers of
->get_vblank_counter, and in the Intel case the actual frame count
register isn't udpated until the next active line is displayed, so we
need to return one more than the frame count register if we're currently
in a vblank period.
However, none of the various ways of doing this is working yet, so
disable the logic for now. This may result in a few missed events, but
should fix the hangs some people have seen due to the current code
tripping the wraparound logic in drm_update_vblank_count.
Jakob Bornecrantz
Alan Hourihane
Jesse Barnes
Jakob Bornecrantz
Thomas Hellstrom
Stuart Bennett
Maarten Maathuis
Ben Skeggs
Mirko
Jesse Barnes
Maciej Cencora
George Sapountzis
Dave Airlie
Eric Anholt