(In reply to vivianhu from comment #7)
> Hi jani, sorry to trouble you. ^-^ But we meet a new problem when we use
> drm-intel-nightly branch,it will report an error and many crash info in
> dmesg, please refer to attachment.
> What is i915/skl_dmc_ver4.bin and where to get it? And Does it will cause
> any problem if skl_dmc_ver4.bin is not loaded?  what is the cut info?

One bug per report please, file new ones for new bugs.

You need the firmware. You can get it from
https://01.org/linuxgraphics/downloads. Hopefully it will be included in
linux-firmware sometime soon.

There's been some back and forth between the naming, see e.g.
http://mid.gmane.org/1433375419-13266-1-git-send-email-rodrigo.vivi@intel.com,
I'm not sure which name is currently used in the download page.