I think this is generally a really bad idea.

> kenv | grep vfs
vfs.root.mountfrom="ufs:/dev/ada0p2"
vfs.root.mountfrom.options="rw"

So we almost always have a : in the path, since the boot loader adds it.
And I think it breaks asking for a root device (say if the root is supposed to be nda0, but that's broken, we may not have the thumb drive you plugged in detected before we get to mountroot prompt).
And many people have zpools on usb, even when booting from ada, so their pools will disappear if the boot path is faster.

In D58869#1351233, @ngie wrote:

the root filesystem is on SATA, NVMe, or ZFS (which are never USB).

That's a bit of a bold claim because ZFS can use USB devices. Is it smart? Hell no. Is it possible? Yes. Also, you would need to deal with all GEOM layers, e.g., graid, gmirror, etc.

I understand what you're trying to solve, but I'm a bit skeptical of the approach being taken given how much things can be stacked on top of one another in FreeBSD from a storage perspective between cam (ctl anyone?), geom, and ZFS.

adress comments

In D58869#1351234, @ngie wrote:

Back in the day this also used to be a flat sleep for all of cam.. it was worse than it is currently.
I feel like better dependency tracking needs to be done to avoid this behavior.
Also... this might be deal with/benefit ukbd as back in the good old days (when there was a flat sleep), the mount root prompt would be unusable with USB keyboards, leaving the sysadmin with a wedged computer terminal asking for a root device and not being able to actually input anything on the keyboard to remedy that situation. Wash-rinse-repeat and the reboot cycle increases because power cycling sometimes reinitializes firmware and has to respin up drives in JBODs, etc (especially in the legacy BIOS and old UEFI days).
So yes, this is an inconvenience, but I would temper removing this based only on the names of functions, etc, alone.
Please go through git blame and see whether or not the change that added this code (functionally, not restylized it) was dealing with the case we think it should be dealing with (quiescing USB root devices) instead of dealing with the vfs_mountroot prompt.

Back in the day this also used to be a flat sleep for all of cam.. it was worse than it is currently.
I feel like better dependency tracking needs to be done to avoid this behavior.
Also... this might be deal with/benefit ukbd as back in the good old days (when there was a flat sleep), the mount root prompt would be unusable with USB keyboards, leaving the sysadmin with a wedged computer terminal asking for a root device and not being able to actually input anything on the keyboard to remedy that situation. Wash-rinse-repeat and the reboot cycle increases because power cycling sometimes reinitializes firmware and has to respin up drives in JBODs, etc (especially in the legacy BIOS and old UEFI days).
So yes, this is an inconvenience, but I would temper removing this based only on the names of functions, etc, alone.
Please go through git blame and see whether or not the change that added this code (functionally, not restylized it) was dealing with the case we think it should be dealing with (quiescing USB root devices) instead of dealing with the vfs_mountroot prompt.

the root filesystem is on SATA, NVMe, or ZFS (which are never USB).

The changes seem reasonable. My general concerns with the change are just related to documentation, follow up and potential future collaboration (especially if I start helping out in this space in the next few months).

Rebase

We can and should add every format we need.

Will there be more format as those from /usr/local/include/linux/videodev2.h ?

address comments

Sorry I'm late, thanks for your patience.

tested on my c720 logitech usb camera. it's .. upside down in vlc for some reason, works in browser. i'll test it with other cameras but i think we can / should iterate on this in head post refactor.

rebase

rebase

rebase

use proper device structure

rebase

rebase

In D54218#1339119, @unitrunker_protonmail.com wrote:

usbconfig stopped reporting my webcam and fingerprint reader. Instead I get 'usbconfig: could not open device: Bad file descriptor'. Problem goes away when these changes are reverted. A very strange side note: libusb20_int.h is missing from base.txz for 15.1-RELEASE (but is in src.txz). I think the problem is I'm testing against 15.1-RELEASE which is too far behind current. I need to find some hardware onto which I can run current.

@markj would you mind eyeballing the mmap / pager stuff here? seuros is looking to refactor uvideo into a generic video layer and then drivers that implement this video API. Since uvideo got a bunch of pager/mmap related changes recently I'd like to make sure this gets done too.