Yeah, I solved the same problem in drm initially by writing a dummy driver too, but now it's been replaced by FB_FLAG_NOWRITE.
This is how we're doing it, it's a bit annoying that we have to check the driver and reach into its softc, ideally flags like that would be a more outer-level thing somehow (?)

Found some interesting discussion from almost a decade ago: https://lists.freebsd.org/pipermail/freebsd-arch/2013-August/014707.html confirming that MONOTONIC should include suspended time:

In D39270#894574, @imp wrote:

How that aligns with Linux and other OSes is going to be messy, I fear.

Oh, what's also pretty neat about the "MONOTONIC includes suspend like OpenBSD" choice is that software doing some security timeouts like sudo does would default to the secure behavior (not prolonging timeouts across suspends) even without doing anything for suspend-awareness / while being just POSIX without any OS-specific code!! :)

In D39270#894014, @imp wrote:

we specifically aligned with Linux here because more software is written for linux and we had a lot of patches in the ports tree to emulate the linux behavior prior to my changes.

In D21612#884481, @dmitryluhtionov_gmail.com wrote:

Сan this link help?
https://patchwork.kernel.org/project/linux-acpi/patch/1472628817-3145-1-git-send-email-wnhuang@google.com/

In D21746#884483, @dmitryluhtionov_gmail.com wrote:

Can this driver generate org.freedesktop.UPower.KbdBacklight events ?

Oops… cr_cansee actually would only deny this with security.bsd.see_other_uids=0 btw. Is there a "fs write" style check anywhere in the common code?

Though, hm, various AT_RESOLVE_BENEATH documentation does collapse it all into one item:

Yeah, makes sense, let's try like this

Hopefully more clear this way?

In D38497#876077, @jfree wrote:

I couldn't figure out a good way to generalize the falloc_noinstall/finstall/fdrop calls since the finstall needs fflags that are unique per special fd. I could move falloc_noinstall and fdrop into sys___specialfd(), I believe.

Wait wait wait… if we decided not to put gettime/settime here, to keep it as an interface only for creating various kinds of descriptors, why are we still going to duplicate the falloc_noinstall/finstall/fdrop dance across the individual functions for each descriptor kind?

In D38459#875880, @kib wrote:

I suggest to add ioctl's to perform the ops on the descriptor, instead of filling the syscall table with more one-purpose entries.

In D38459#875436, @markj wrote:

One wrinkle that I can see is that timerfd lets you specify a clock ID, but this implementation doesn't really do anything with it...

just implement these to as syscalls leaving __specialfd for descriptor creation

sure, D38445 LGTM

ok, let's go with D38392

Remove $FreeBSD$ tags, add header include to the .c file to fix missing-prototype

In D28703#873145, @emaste wrote:

Do you have a public Git branch somewhere that I can fetch your changes from?

btw, what toggles the error is --(no-)undefined-version, no became the default. It seems difficult to make *everything* work with --no-undefined-version, but this was the only thing in the kernel.

Rebase after D38222

Yes, it has failed. I wouldn't be that bothered with a little warning :)

Rebased. Ping!

rebased / author name changed / etc. (dang it's been a year)

rebased (bye bye MIPS \o/). ping!

rebased patch, no functional changes. ping!

rebased patch, no changes

Add man page and sys/conf/files entry

update via git-arc

oops, also don't add $FreeBSD$ to new files

Added a manpage and a files entry for building into the kernel

In D38351#871465, @oshogbo wrote:

Are you sure this patch is correctly generated?
I know that you said you want the review of the general idea, but still..

added patch context

remove submodule patch

ping

Especially if this will be per-CPU, it should probably be more compact. A \n per cache level seems like a lot of dmesg spam.

• rebase
• add SYSUNINIT for deallocating the strings
• remove useless null check (kfree supports null)

add missed case

As mentioned in the comment, around 3500 is what I measured for a really hard press, so I rounded up to the next power of two, that's why it's 4096.

Endian convert the initial 32 bit field, use given IDs, do not report width major/minor

switch to macro