when using a KVM.
There is no actual solution possible, but this gets us pretty close.
Typically when switching back to a FreeBSD box and moving the mouse
wild data is produced, because the protocol's validation/checksum
system is extremely weak it is impossible to determine that we're
out of sync before dropping several bogus packets to user land.
The actual solution that appears to offer the best clamping of
jitter is to buffer the mouse packets if we've not seen mouse
activity for more than .5 seconds. Then waiting to flush that data
for 1/20th of a second. If within that 20th of a second we get any
packets that do fail the weak test we drop the entire queue and
back off accepting data from the mouse for 2 seconds and then repeat
the whole deal.
You can still get _some_ jitter, notably if you switch to the FreeBSD
box, then move the mouse just enough to generate one or two packets.
Those packets may be bogus, but may still pass the validity check.
One way to finally kill the problem once and for all is to check
the initial packets for "wild" values. Typically one sees packets
in the +/-60 range during normal operation, however when bogus data
is generated it's typically near the outer range of +/-120 or more,
those packets would be a good candidate for dropping or clamping.
I've been running with this for several weeks now and it has
significantly helped me stay sane even with a piece of junk Belkin
KVM causing wild jitter each and every time I switch.
Lastly I'd like to note that my experience with Windows shows me that
somehow the Microsoft PS/2 driver typically avoids this problem, but
that may only be possible when running the mouse in a dumb-ed down PS/2
mode that Belkin recommends on their site.
thread being waken up. The thread waken up can run at a priority as
high as after tsleep().
- Replace selwakeup()s with selwakeuppri()s and pass appropriate
priorities.
- Add cv_broadcastpri() which raises the priority of the broadcast
threads. Used by selwakeuppri() if collision occurs.
Not objected in: -arch, -current
Even if we have no AT keyboard, an AT keyboard is registered because
it's probed with KB_CONF_PROBE_ONLY flag set during console initialization.
Unregister the keyboard if it doesn't present while second probe.
This should fix USB keyboard only case without 'kbdcontrol -k /dev/kbd1'.
disabled.
- Change the apm driver to match the acpi driver's behavior by checking to
see if the device is disabled in the identify routine instead of in the
probe routine. This way if the device is disabled it is never created.
Note that a few places (ips(4), Alpha SMP) used "disable" instead of
"disabled" for their hint names, and these hints must be changed to
"disabled". If this is a big problem, resource_disabled() can always be
changed to honor both names.
bus_dma MD code for AMD64. (And a trivial ifdef update in dev/kbd because
of this). More updates are needed here to take advantage of the 64 bit
instructions.
Approved by: re (blanket amd64/*)
branches:
Initialize struct cdevsw using C99 sparse initializtion and remove
all initializations to default values.
This patch is automatically generated and has been tested by compiling
LINT with all the fields in struct cdevsw in reverse order on alpha,
sparc64 and i386.
Approved by: re(scottl)
of KBDIO_DEBUG which may be defined in the kernel config (as it is in NOTES).
This kind of bug is a _really_ horribly thing as we end up with one bit
of code thinking a particular structure is 136 bytes and another that it
is only 112 bytes.
Ideally all places would remember to #include the right "opt_foo.h" file,
but I think in practice file containing the variable sized struct should
#include it explicitly as a precaution.
Detected by: FlexeLint
but since pc hardware only allows one AT-style keyboard controller, this
doesn't seem particularly urgent. (I do not know what the old sunriver
remote keyboard/mouse/vga cards do, that might be an exception).
Problem:
selwakeup required calling pfind which would cause lock order
reversals with the allproc_lock and the per-process filedesc lock.
Solution:
Instead of recording the pid of the select()'ing process into the
selinfo structure, actually record a pointer to the thread. To
avoid dereferencing a bad address all the selinfo structures that
are in use by a thread are kept in a list hung off the thread
(protected by sellock). When a selwakeup occurs the selinfo is
removed from that threads list, it is also removed on the way out
of select or poll where the thread will traverse its list removing
all the selinfos from its own list.
Problem:
Previously the PROC_LOCK was used to provide the mutual exclusion
needed to ensure proper locking, this couldn't work because there
was a single condvar used for select and poll and condvars can
only be used with a single mutex.
Solution:
Introduce a global mutex 'sellock' which is used to provide mutual
exclusion when recording events to wait on as well as performing
notification when an event occurs.
Interesting note:
schedlock is required to manipulate the per-thread TDF_SELECT
flag, however if given its own field it would not need schedlock,
also because TDF_SELECT is only manipulated under sellock one
doesn't actually use schedlock for syncronization, only to protect
against corruption.
Proc locks are no longer used in select/poll.
Portions contributed by: davidc
- Count the number of this error.
- When the error is detected for the first time, the psm driver will
throw few data bytes (up to entire packet size) and see if it can
get back to sync.
- If the error still persists, the psm driver disable/enable the mouse
and see if it works.
- If the error still persists and the count goes up to 20,
the psm driver reset and reinitialize the mouse. The counter
is reset to zero.
- It also discards an incomplete data packet when the interval
between two consequtive bytes are longer than pre-defined timeout
(2 seconds). The last byte which arrived late will be regarded as
the first byte of a new packet. This is louie's idea.
You may see the following error logs during the above operations:
"psmintr: delay too long; resetting byte count"
"psmintr: out of sync (%04x != %04x)"
"psmintr: discard a byte (%d)"
"psmintr: re-enable the mouse"
"psmintr: reset the mouse"
MFC after: 1 month
problems currently experienced in -CURRENT.
This should fix the problem that the PS/2 mouse is detected
twice if the acpi module is not loaded on some systems.
I am not sure if this is absolutely necessary on all systems. Yet,
there certainly are motherboards and notebook systems which require
this, although there are other systems which just don't. I hope we
shall know when to do this on which systems, as the development of our
ACPI subsystem progresses... (I know we didn't need this for the APM
resume.)
- Add workaround for the problematic PnP BIOS which does not assign
irq resource for the PS/2 mouse device node; if there is no irq
assigned for the PS/2 mouse node, refer to device.hints for an
irq number. If we still don't find an irq number in the hints
database, use a hard-coded value.
- Delete unused ivars.
- Bit of clean up in probe/attach.
- Add PnP ID for the PS/2 mouse port on some IBM ThinkPad models.
Note ALL MODULES MUST BE RECOMPILED
make the kernel aware that there are smaller units of scheduling than the
process. (but only allow one thread per process at this time).
This is functionally equivalent to teh previousl -current except
that there is a thread associated with each process.
Sorry john! (your next MFC will be a doosie!)
Reviewed by: peter@freebsd.org, dillon@freebsd.org
X-MFC after: ha ha ha ha
more cleanly and consistently in all APCI, PnP BIOS, and "hint"
cases.
NOTE: this doesn't necessarily solve the problem that the PS/2
mouse is not detected after the recent ACPI update.
events. Otherwise you would see unexpected results if shift or
locking keys are defined to give different actions depending
on other shift/locking keys' state.
Please keep the ukbd module and the kernel in sync, otherwise
the USB keyboard won't work after this change.
MFC after: 10 days
- Replace some very poorly thought out API hacks that should have been
fixed a long while ago.
- Provide some much more flexible search functions (resource_find_*())
- Use strings for storage instead of an outgrowth of the rather
inconvenient temporary ioconf table from config(). We already had a
fallback to using strings before malloc/vm was running anyway.
