signals delivered to a process writing to the audio device the
system: if you try
cat /dev/zero > /dev/dsp (or cat /dev/zero > /dev/pcaudio)
and press Ctrl-C : for a second or two the system appears to freeze
(e.g. the cursor will disappear if you move the mouse, xclock
blocks, etc.). I think that interrupts etc. still run so the problem
is not too terrible, but still annoying
[ The problems appears to also be in isa/pcaudio.c, though that is ignored ]
Submitted by: Luigi Rizzo <luigi@labinfo.iet.unipi.it>
Highlights:
* Simple model for underlying hardware.
* Hardware basis for timekeeping can be changed on the fly.
* Only one hardware clock responsible for TOD keeping.
* Provides a real nanotime() function.
* Time granularity: .232E-18 seconds.
* Frequency granularity: .238E-12 s/s
* Frequency adjustment is continuous in time.
* Less overhead for frequency adjustment.
* Improves xntpd performance.
Reviewed by: bde, bde, bde
Uncommented css0. It compiles OK.
Moved trix0 so that it compiles OK when uncommented. Uncommented
it. Drivers with the same interrupt handler must be together in
config files so that config(8)'s simple avoidance of redundant
declarations of interrupt handlers works (config emits a declaration
unless it would duplicate the previous one).
Commented out NO_LKM. Negative options should not be configured
in LINT. There should be no negative options for subsystems.
LKMs should never have been standard or the default.
select/poll and DEVFS changes, which are limited to an include/define
in sound.h and the actual select/poll implementation in sound.c
[ This commit is blind, but the code is similar enough that there will
hopefully be no problems. ]
The differences Terrys patch and this patch are:
* Remove a lot of un-needed comments.
* Don't put l_hotchar at the front of stuct linesw, there is no need to.
* Use the #defines for the hotchar in the SLIP and PPP line disciplines
with macros. This breaks if the functions are replaced by macros with
unsuitable semantics. Define a MAX() macro unconditionally instead.
max() is unsuitable since we need a constant expression. Don't define
MIN() - we never used min().
is "acquired". This fixes a TSC biasing error of about 10 msec when
pcaudio is active.
Update `time' before calling hardclock() when timer0 is being released.
This is not known to be important.
Added some delays in writertc(). Efficiency is not critical here, unlike
in rtcin(), and we already use conservative delays there.
Don't touch the hardware when machdep.i8254_freq is being changed but
the maximum count wouldn't change. This fixes jitter of up to 10 msec
for most small adjustments to machdep.i8254_freq. When the maximum
count needs to change, the hardware should be adjusted more carefully.
i386_set_ioperm(). Don't use a magic number for the bound.
Fixed missing bounds checking in i386_get_ioperm(). Don't use a
magic number for the bound elsewhere in this function.
Removed some bogus initializers.
