If having problems with update to Radeon Linux 4.7.10

[David Shao]

I don't have the Hawaii Pro Radeon R9 290 hardware, but it appears
even on Linux certain cards
have problems with dpm and older firmware:

Radeonsi on Grenada cards (r9 390) exceptionally unstable and poorly performing

https://bugs.freedesktop.org/show_bug.cgi?id=91880

A short-term attempt to just get the card to work at all in xorg is to
try and use
the TUNABLE_INTs in sys/dev/drm/radeon/radeon_drv.c.

In particular the radeon dpm setting can be a problem even on Linux.
So perhaps try and disable it using:

TUNABLE_INT("drm.radeon.dpm", &radeon_dpm);
MODULE_PARM_DESC(dpm, "DPM support (1 = enable, 0 = disable, -1 = auto)");
module_param_named(dpm, radeon_dpm, int, 0444);

The medium-term attempted fix as mentioned in the above bug report is to try and
update some firmware and also some of the Radeon drm code to detect
this firmware.

One sample patch that only arrived at Linux 4.8 is:

drm/radeon: load different smc firmware on some CI variants

The power tables on some variants require different firmware.
This may fix stability issues on some newer CI parts.

https://github.com/torvalds/linux/commit/b2ea0dcd2790949802230bada9416d2362280138

This is one source for Radeon firmware:

https://people.freedesktop.org/~agd5f/radeon_ucode/

https://people.freedesktop.org/~agd5f/radeon_ucode/hawaii/

https://people.freedesktop.org/~agd5f/radeon_ucode/k/