[ 162.831515] Loading crystalhd v3.10.0
[ 162.831638] crystalhd 0000:04:00.0: Starting Device:0x1615
[ 162.837846] crystalhd 0000:04:00.0: irq 45 for MSI/MSI-X
[ 195.409801] crystalhd 0000:04:00.0: Opening new user[0] handle
[ 196.086934] crystalhd 0000:04:00.0: [crystalhd_flea_download_fw]: step 7. Error bit occured. RetVal:c00018
[ 196.086966] crystalhd 0000:04:00.0: [crystalhd_flea_download_fw]: step 7. Firmware image signature failure.
[ 196.086993] crystalhd 0000:04:00.0: Firmware Download Failure!! - -1
[ 196.214372] crystalhd 0000:04:00.0: Closing user[0] handle via ioctl with mode 10200
When that happens I have to reboot once more and it's usually fine again.
However, now I just rebooted 5 times and I still get this error.
So I think this issue really needs an actual solution instead of just rebooting and hoping for the best.
I tried both firmware blobs (bcm70015fw.bin) from
libcrystalhd-git.3.4.5-1
crystalhd-git.3.4.5-1
which are both from AUR, and the two firmware files should actually be identical anyway, to no avail.
I think the only thing I changed before this reboot was changing the hwclock to UTC, nothing that should actually affect the crystalhd driver in any way.
Edit:
I was able to get it going again by _shutting down_ instead of just warm-rebooting, so the notebook was turned off completely in between.
I don't think this counts as SOLVED though. =P