We used to have a single wait channel inside the kernel which could be
used by threads that just wanted to sleep for some time (the next
second). The old TTY layer was the only piece of code that still used
lbolt, because I already removed the use of lbolt from the NFS clients
and the VFS syncer.
Approved by: philip
I initially didn't want to integrate the Xen console driver, because it
did not receive any testing. Kip Macy suggested that I'd better check it
in right now, because this is the easiest way for him to test it while
he is working on the Xen import.
Requested by: kmacy
For some reason, sys/sys/tty.h was only half patched. This went by
unnoticed, because the copyright notice on the top already displayed my
name, so I thought the file went in properly.
Reported by: kmacy
The previous commit also included changes to all the system call lists,
but it is a tradition to update these lists in a second commit, so rerun
make sysent to update the $FreeBSD$ tags inside these files to refer to
the latest version of syscalls.master.
Requested by: rwatson
The last half year I've been working on a replacement TTY layer for the
FreeBSD kernel. The new TTY layer was designed to improve the following:
- Improved driver model:
The old TTY layer has a driver model that is not abstract enough to
make it friendly to use. A good example is the output path, where the
device drivers directly access the output buffers. This means that an
in-kernel PPP implementation must always convert network buffers into
TTY buffers.
If a PPP implementation would be built on top of the new TTY layer
(still needs a hooks layer, though), it would allow the PPP
implementation to directly hand the data to the TTY driver.
- Improved hotplugging:
With the old TTY layer, it isn't entirely safe to destroy TTY's from
the system. This implementation has a two-step destructing design,
where the driver first abandons the TTY. After all threads have left
the TTY, the TTY layer calls a routine in the driver, which can be
used to free resources (unit numbers, etc).
The pts(4) driver also implements this feature, which means
posix_openpt() will now return PTY's that are created on the fly.
- Improved performance:
One of the major improvements is the per-TTY mutex, which is expected
to improve scalability when compared to the old Giant locking.
Another change is the unbuffered copying to userspace, which is both
used on TTY device nodes and PTY masters.
Upgrading should be quite straightforward. Unlike previous versions,
existing kernel configuration files do not need to be changed, except
when they reference device drivers that are listed in UPDATING.
Obtained from: //depot/projects/mpsafetty/...
Approved by: philip (ex-mentor)
Discussed: on the lists, at BSDCan, at the DevSummit
Sponsored by: Snow B.V., the Netherlands
dcons(4) fixed by: kan
place to add this connection, since the interrupt is for a GPIO pin,
but since we have no alternative at the moment...
Submitted by: Hans Petter Selasky
we free memory from underneath them.
This fixes an occasional panic I've been seeing in softclock() where a bad
pointer would be encountered when pushing DTrace hard.
The PCM's sound.h file only seems to include <sys/tty.h>, because
channel_if seems to require selinfo. Just replace it with
<sys/selinfo.h>.
There's no real problem with including <sys/tty.h> here, even with
MPSAFE TTY, but <sys/tty.h> is something that should be used by the TTY
layer, its driver and code that integrated it with the process tree.
corresponding USAGE should be skipped as well.
For example, below is a report desc fragment of some mouse:
COLLECTION
...
USAGE TWHEEL
FEATURE ...
...
USAGE WHEEL
INPUT ...
...
END COLLECTION
"USAGE TWHEEL" should be consumed after the FEATURE item is skipped,
otherwise, the INPUT item will be assigned to "USAGE TWHEEL" later,
other than "USAGE WHEEL".
Tested by: Grzegorz Blach
PR: usb/125941
In order to CATER this, DDB buffered output can be choosen at compile
time through the option DDB_BUFR_SIZE=nbytes where nbytes choose the size
of the buffer (suggested size is 128 bytes), which should be manually
specified in any interested config file.
Sponsored by: Nokia
