timeout()/untimeout() API:
- Clients supply callout handle storage, thus eliminating problems of
resource allocation.
- Insertion and removal of callouts is constant time, important as
this facility is used quite a lot in the kernel.
The old timeout()/untimeout() API has been removed from the kernel.
if the line discipline is ignoring carrier (e.g., via comparam()'s
setting of sc->sc_msr_mask). Move PPS timestamp outside the normal
status-change processing, and ignore sc_msr_mask when testing
for PPS events.
* The fact that IIR_NOPEND was not set on entry does *not* mean that no
transmission was in progress. Besides, we don't want to throw away receive
interrupts either.
* In the !clearirq case, we didn't splx().
1. don't clear the irq unless it was clear before transmitting
2. also do various bus_space_barrier() ops
Stops console from freezing when kprintf interrupts tty driver output.
- In the console getc routine, block until a character becomes ready
(no, really, we mean it). This routine should _never_ time out.
- In the console putc routine, if the UART has trouble, do NOT proceed
to print a diagnostic message, which would recursively invoke the
console putc routine ad nauseum.
This is useful in the case where an attachment's probe routine
verifies that there is indeed hardware present but something goes
"wrong" in the attach causing the device to be unusable. (Without
keeping track of this, in that case incorrect ports could be
accessed or uninitted pointers could be deferenced on open or at
other times.)
* Make the ring buffer size and water marks patchable, and allocate the buffer
separately.
* Do the ttymalloc() at attach time.
* Reorganize the receive buffer so the status and data pair are next to each
other. This is slightly faster.
* Make sure we actually do turn off interrupts in comclose() if we have DDB
configured and it's not the console. (D'oh!!!!)
* When we exhaust the current transmit run, turn off transmit interrupts in
comintr(), so we're fairly sure we don't get another one.
* Nuke the silly lsrmap[] idea; it's slower in the normal case.
* Cache the l_rint pointer in the soft interrupt routine.
simonb