Intel Valleyview & Cherry Trail Hardware Likely To See Fastboot Flipped On

With the upcoming Linux 5.1 cycle we'll likely see Intel "Fastboot" enabled by default at least for Skylake hardware and newer, but Cherry Trail and Valleyview might also get this special treatment.

Fastboot in the Intel Linux perspective is about avoiding unnecessary mode-sets at boot time in order to provide a cleaner boot experience, or as some put it so elegantly, "avoid an ugly modeset during boot." Fastboot has been a long time coming after several failed attempts over the years to enable it by default. But with the current mature state of the Intel DRM/KMS driver and recent generations playing well with Fastboot, it's reasonable to enable it by default.

Hans de Goede of Red Hat has been pursuing the Intel Fastboot by default as part of his broad effort on improving Fedora's boot experience. With Skylake and newer squared away, he's been exploring what other generations of Intel hardware may be safe to flip this feature on by default rather than requiring the i915.fastboot=1 boot parameter.

In his latest testing, he thinks Cherry Trail and Valleyview/Bay-Trail Atom hardware is a safe bet:

I've extensively tested fastboot=1 support on over 50 different Bay- and Cherry-Trail devices. Testing DSI and eDP panels as well as HDMI output (and even DP over Type-C on one device).

All 50 devices work fine with fastboot=1. On 2 devices their DSI panel turns black as soon as the i915 driver loads when fastboot=0, so having fastboot enabled is required for these 2 to work properly (for lack of a better fix).

So if this patch gets picked up, these generations of Intel SoC hardware will also see Fastboot by default.