there appear to be devices out there such as Realtek RTL2838UHIDIR
SDR that do not process control transfers correctly, ignoring the
high byte of the wLength field. to work around this, we specify an
odd number of bytes for read sizes >= 256 which keeps the low byte
0xFF.
we did not interpret the $rootdir and $rootspec environment
variables right. $rootdir is what gets bound to / (usually /root)
and $rootspec is the mountspec of /root.
i'v been seeing the error condition described above in the
Slowbulkin comment. so i'm enabling the work arround which
seems to fix the lockup.
in the split transaction case where we want to start the
transaction at frame start, acquire the ctlr lock *before*
checking if we are in the right frame number. so the start
will happen atomically. checking the software ctlr->sofchan
instead of checking the interrupt mask register seems to
be quicker.
setting the haint mask bit for the chan under ctlr lock
in chanio() instead of chanwait() avoids needing to acquire
the ctlr lock twice.
mask wakechan bits with busychan bitmap in interrupt handlers
so we will not try to wake up released chans by accident.
sleep() and tsleep() might get interrupted so we have to
release the split qlock in the split transaction case and
in all cases, make sure to halt the channel before release.
add some common debug functions to dump channel and controller
registers.
we have to ensure that all stores saving the process state
have completed before setting up->mach = nil in the scheduler.
otherwise, another cpu could observe up->mach == nil while
the stores such as the processes p->sched label have not finnished.
vmx uses non portable word unpacking macros, breaking
the build for arm64. vmx only works on a pc anyway.
this forces objtype to 386 on these machines, similar
to what the kernel mkfiles do.
attached is a patch to fix receive in the 8169 chip on my thinkpad
A485. i'm not sure why, but the same thing was done in 3d56a0fc4645
for Macv45.
nick
