When booting with the newest kernel from the amd-staging-4.7 branch from
https://cgit.freedesktop.org/~agd5f/linux/, all connected monitors will go
blank and stay blank indefinitely. The power indicator on the monitors will
start to blink as if there was no signal.

This is with commit 680da8633ae17cdea8fddd1ede87253325c8ca25. With an older
commit, d330e1e9c232895dbd0c183a647d41d54ecc0884, this branch still works.

DAL is enabled in the config in both cases.

The graphics card is a Sapphire Nitro Radeon R9 380X.

There are three monitors connected in total, one to the DVI-I port, one to the
DVI-D port and one to the DisplayPort.

I am using this particular branch as a workaround for the bug described in
https://bugs.freedesktop.org/show_bug.cgi?id=91202