For a slightly thorough explaination, please refer to
[1] http://people.freebsd.org/~ariff/SOUND_4.TXT.html .
Summary of changes includes:
1 Volume Per-Channel (vpc). Provides private / standalone volume control
unique per-stream pcm channel without touching master volume / pcm.
Applications can directly use SNDCTL_DSP_[GET|SET][PLAY|REC]VOL, or for
backwards compatibility, SOUND_MIXER_PCM through the opened dsp device
instead of /dev/mixer. Special "bypass" mode is enabled through
/dev/mixer which will automatically detect if the adjustment is made
through /dev/mixer and forward its request to this private volume
controller. Changes to this volume object will not interfere with
other channels.
Requirements:
- SNDCTL_DSP_[GET|SET][PLAY|REC]_VOL are newer ioctls (OSSv4) which
require specific application modifications (preferred).
- No modifications required for using bypass mode, so applications
like mplayer or xmms should work out of the box.
Kernel hints:
- hint.pcm.%d.vpc (0 = disable vpc).
Kernel sysctls:
- hw.snd.vpc_mixer_bypass (default: 1). Enable or disable /dev/mixer
bypass mode.
- hw.snd.vpc_autoreset (default: 1). By default, closing/opening
/dev/dsp will reset the volume back to 0 db gain/attenuation.
Setting this to 0 will preserve its settings across device
closing/opening.
- hw.snd.vpc_reset (default: 0). Panic/reset button to reset all
volume settings back to 0 db.
- hw.snd.vpc_0db (default: 45). 0 db relative to linear mixer value.
2 High quality fixed-point Bandlimited SINC sampling rate converter,
based on Julius O'Smith's Digital Audio Resampling -
http://ccrma.stanford.edu/~jos/resample/. It includes a filter design
script written in awk (the clumsiest joke I've ever written)
- 100% 32bit fixed-point, 64bit accumulator.
- Possibly among the fastest (if not fastest) of its kind.
- Resampling quality is tunable, either runtime or during kernel
compilation (FEEDER_RATE_PRESETS).
- Quality can be further customized during kernel compilation by
defining FEEDER_RATE_PRESETS in /etc/make.conf.
Kernel sysctls:
- hw.snd.feeder_rate_quality.
0 - Zero-order Hold (ZOH). Fastest, bad quality.
1 - Linear Interpolation (LINEAR). Slightly slower than ZOH,
better quality but still does not eliminate aliasing.
2 - (and above) - Sinc Interpolation(SINC). Best quality. SINC
quality always start from 2 and above.
Rough quality comparisons:
- http://people.freebsd.org/~ariff/z_comparison/
3 Bit-perfect mode. Bypasses all feeder/dsp effects. Pure sound will be
directly fed into the hardware.
4 Parametric (compile time) Software Equalizer (Bass/Treble mixer). Can
be customized by defining FEEDER_EQ_PRESETS in /etc/make.conf.
5 Transparent/Adaptive Virtual Channel. Now you don't have to disable
vchans in order to make digital format pass through. It also makes
vchans more dynamic by choosing a better format/rate among all the
concurrent streams, which means that dev.pcm.X.play.vchanformat/rate
becomes sort of optional.
6 Exclusive Stream, with special open() mode O_EXCL. This will "mute"
other concurrent vchan streams and only allow a single channel with
O_EXCL set to keep producing sound.
Other Changes:
* most feeder_* stuffs are compilable in userland. Let's not
speculate whether we should go all out for it (save that for
FreeBSD 16.0-RELEASE).
* kobj signature fixups, thanks to Andriy Gapon <avg@freebsd.org>
* pull out channel mixing logic out of vchan.c and create its own
feeder_mixer for world justice.
* various refactoring here and there, for good or bad.
* activation of few more OSSv4 ioctls() (see [1] above).
* opt_snd.h for possible compile time configuration:
(mostly for debugging purposes, don't try these at home)
SND_DEBUG
SND_DIAGNOSTIC
SND_FEEDER_MULTIFORMAT
SND_FEEDER_FULL_MULTIFORMAT
SND_FEEDER_RATE_HP
SND_PCM_64
SND_OLDSTEREO
Manual page updates are on the way.
Tested by: joel, Olivier SMEDTS <olivier at gid0 d org>, too many
unsung / unnamed heroes.
middle of senetences. This also makes the code more consistent
with the corresponding FFS code.
- Use 2-space sentences breaks consistently.
Suggested by: bde
mtx_destroy() of the pool mutex to after SVC_RELEASE(), because
the pool mutex was still locked when soclose() was called by svc_dg_destroy().
To fix this, an mtx_unlock() was added where mtx_destroy() was before
r193436.
Reviewed by: jhb
Tested by: pho
Approved by: rwatson (mentor)
in Freescale system-on-chip devices.
The following algorithms and schemes are currently supported:
- 3DES, AES, DES
- MD5, SHA1, SHA256, SHA384, SHA512
Reviewed by: philip
Obtained from: Freescale, Semihalf
behavior for unicode support in UDF so as not to conflict with the MAC
Framework.
Note that Apple's XNU kernel also uses #ifdef MAC for the MAC Framework.
Suggested by: pjd
MFC after: 3 days
adjust conf/files and modules' Makefiles accordingly.
No code or ABI changes so this and most of previous related
changes can be easily MFC'ed
MFC after: 5 days
pipes, queues, tags, rule numbers and so on.
These are all different namespaces, and the only thing they have in
common is the fact they use a 16-bit slot to represent the argument.
There is some confusion in the code, mostly for historical reasons,
on how the values 0 and 65535 should be used. At the moment, 0 is
forbidden almost everywhere, while 65535 is used to represent a
'tablearg' argument, i.e. the result of the most recent table() lookup.
For now, try to use explicit constants for the min and max allowed
values, and do not overload the default rule number for that.
Also, make the MTAG_IPFW declaration only visible to the kernel.
NOTE: I think the issue needs to be revisited before 8.0 is out:
the 2^16 namespace limit for rule numbers and pipe/queue is
annoying, and we can easily bump the limit to 2^32 which gives
a lot more flexibility in partitioning the namespace.
MFC after: 5 days
Clists were originally used by the TTY layer as a text buffer interface.
The advantage of clists were that it would allocate a small set of
additional buffers that could be shared between TTYs when needed. In
the modern days we can just allocate some more KBs of memory to keep the
TTYs satisfied. The global cfreelist also requires synchronisation,
which may not be useful when trying to improve scalability.
The MPSAFE TTY layer uses its own text buffers (ttyinq and ttyoutq). We
had a small amount of drivers in the tree that still uses clists, like
the old USB stack and some keyboard drivers. With the old USB stack gone
and the keyboard drivers changed to use a circular buffer, we can safely
remove clists from the kernel.
These two drivers seem to be the last consumers of clists. clists are
quite overengineered for simple circular buffers, so I'm adding similar
buffer management routines to the kbd and kbdmux drivers. The input
buffer is now part of the softc structures, instead of having
dynamically allocated cblocks.
and used in a large number of files, but also because an increasing number
of incorrect uses of MAC calls were sneaking in due to copy-and-paste of
MAC-aware code without the associated opt_mac.h include.
Discussed with: pjd
structure contents are a bad idea in the kernel for binary
compatibility reasons, and this is a single pointer that is now included
in compiles by default anyway due to options MAC being in GENERIC.
+ move ipfw and dummynet hooks declarations to raw_ip.c (definitions
in ip_var.h) same as for most other global variables.
This removes some dependencies from ip_input.c;
+ remove the IPFW_LOADED macro, just test ip_fw_chk_ptr directly;
+ remove the DUMMYNET_LOADED macro, just test ip_dn_io_ptr directly;
+ move ip_dn_ruledel_ptr to ip_fw2.c which is the only file using it;
To be merged together with rev 193497
MFC after: 5 days
stuff to its own directory, and cleaning headers and dependencies:
In this commit:
+ remove one use of a typedef;
+ document dn_rule_delete();
+ replace one usage of the DUMMYNET_LOADED macro with its value;
No MFC planned until the cleanup is complete.
a KASSERT to handle it. People are likely to turn off INVARIANTS RSN
and loading an old module can cause garbage-in here.
I saw the issue with an older nvidia driver (x11/nvidia-driver) loading
into a new kernel - a crash wasn't seen 'till sysctl_kern_malloc_stats().
I was lucky that mtp->ks_shortdesc was NULL and not something horrible.
While I'm here, KASSERT that malloc_uninit() isn't passed something that's
not in kmemstatistics.
MFC after: 3 weeks
Without this fix pte_vatopa() was not able to retrieve physical address of
data structures inside kernel, for example EFAULT was reported while acessing
/dev/kmem ('netstat -nr').
Submitted by: Piotr Ziecik
Obtained from: Semihalf
