drm/i915: don't enable self-refresh on Ironlake

We don't know how to enable it safely, especially as outputs turn on and
off.  When disabling LP1 we also need to make sure LP2 and 3 are already
disabled.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=29173
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=29082
Reported-by: Chris Lord <[email protected]>
Signed-off-by: Jesse Barnes <[email protected]>
Tested-by: Daniel Vetter <[email protected]>
Cc: [email protected]
Signed-off-by: Chris Wilson <[email protected]>
2 files changed