| Age | Commit message (Collapse) | Author | Files | Lines |
|---|
|
As long as I know, in userspace, '%c' format on printing format for
tracepoint is replaced with '>c<' by existent tracing program; i.g.
'perf-trace' and 'trace-cmd'. This is inconvenient.
This commit replaces the format with '%s'. The length of letters in the
format string is not changed, thus this commit doesn't increase object
size.
In theory, I should work for improvements of these tracing programs, but
here I'd like to save my time to work for the other projects.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
In design of ALSA PCM core, status and control data for runtime of ALSA
PCM substream are shared between kernel/user spaces by page frame
mapping with read-only attribute. Both of hardware-side and
application-side position on PCM buffer are maintained as a part of
the status data. In a view of ALSA PCM application, these two positions
can be updated by executing ioctl(2) with some commands.
There's an event of tracepoint for hardware-side position; 'hwptr'.
On the other hand, no events for application-side position. This commit
adds a new event for this purpose; 'applptr'. When the application-side
position is changed in kernel space, this event is probed with useful
information for developers.
I note that the event is not probed for all of ALSA PCM applications, When
applications are written by read/write programming scenario, the event is
surely probed. The applications execute ioctl(2) with
SNDRV_PCM_IOCTL_[READ|WRITE][N/I]_FRAMES to read/write any PCM frame, then
ALSA PCM core updates the application-side position in kernel land.
However, when applications are written by mmap programming scenario, if
maintaining the application side position in kernel space accurately,
applications should voluntarily execute ioctl(2) with
SNDRV_PCM_IOCTL_SYNC_PTR to commit the number of handled PCM frames. If
not voluntarily, the application-side position is not changed, thus the
added event is not probed.
There's a loophole, using architectures to which ALSA PCM core judges
non cache coherent. In this case, the status and control data is not mapped
into processe's VMA for any applications. Userland library, alsa-lib, is
programmed for this case. It executes ioctl(2) with
SNDRV_PCM_IOCTL_SYNC_PTR command every time to requiring the status and
control data.
ARM is such an architecture. Below is an example with serial sound interface
(ssi) on i.mx6 quad core SoC. I use v4.1 kernel released by fsl-community
with patches from VIA Tech. Inc. for VAB820, and my backport patches for
relevant features for this patchset. I use Ubuntu 17.04 from
ports.ubuntu.com as user land for armhf architecture.
$ aplay -v -M -D hw:imx6vab820sgtl5,0 /dev/urandom -f S16_LE -r 48000 --period-size=128 --buffer-size=256
Playing raw data '/dev/urandom' : Signed 16 bit Little Endian, Rate 48000 Hz, Mono
Hardware PCM card 0 'imx6-vab820-sgtl5000' device 0 subdevice 0
Its setup is:
stream : PLAYBACK
access : MMAP_INTERLEAVED
format : S16_LE
subformat : STD
channels : 1
rate : 48000
exact rate : 48000 (48000/1)
msbits : 16
buffer_size : 256
period_size : 128
period_time : 2666
tstamp_mode : NONE
tstamp_type : MONOTONIC
period_step : 1
avail_min : 128
period_event : 0
start_threshold : 256
stop_threshold : 256
silence_threshold: 0
silence_size : 0
boundary : 1073741824
appl_ptr : 0
hw_ptr : 0
mmap_area[0] = 0x76f98000,0,16 (16)
$ trace-cmd record -e snd_pcm:hwptr -e snd_pcm:applptr
$ trace-cmd report
...
60.208495: applptr: pcmC0D0p/sub0: prev=1792, curr=1792, avail=0, period=128, buf=256
60.208633: applptr: pcmC0D0p/sub0: prev=1792, curr=1792, avail=0, period=128, buf=256
60.210022: hwptr: pcmC0D0p/sub0: IRQ: pos=128, old=1536, base=1536, period=128, buf=256
60.210202: applptr: pcmC0D0p/sub0: prev=1792, curr=1792, avail=128, period=128, buf=256
60.210344: hwptr: pcmC0D0p/sub0: POS: pos=128, old=1664, base=1536, period=128, buf=256
60.210348: applptr: pcmC0D0p/sub0: prev=1792, curr=1792, avail=128, period=128, buf=256
60.210486: applptr: pcmC0D0p/sub0: prev=1792, curr=1792, avail=128, period=128, buf=256
60.210626: applptr: pcmC0D0p/sub0: prev=1792, curr=1920, avail=0, period=128, buf=256
60.211002: applptr: pcmC0D0p/sub0: prev=1920, curr=1920, avail=0, period=128, buf=256
60.211142: hwptr: pcmC0D0p/sub0: POS: pos=128, old=1664, base=1536, period=128, buf=256
60.211146: applptr: pcmC0D0p/sub0: prev=1920, curr=1920, avail=0, period=128, buf=256
60.211287: applptr: pcmC0D0p/sub0: prev=1920, curr=1920, avail=0, period=128, buf=256
60.212690: hwptr: pcmC0D0p/sub0: IRQ: pos=0, old=1664, base=1536, period=128, buf=256
60.212866: applptr: pcmC0D0p/sub0: prev=1920, curr=1920, avail=128, period=128, buf=256
60.212999: hwptr: pcmC0D0p/sub0: POS: pos=0, old=1792, base=1792, period=128, buf=256
60.213003: applptr: pcmC0D0p/sub0: prev=1920, curr=1920, avail=128, period=128, buf=256
60.213135: applptr: pcmC0D0p/sub0: prev=1920, curr=1920, avail=128, period=128, buf=256
60.213276: applptr: pcmC0D0p/sub0: prev=1920, curr=2048, avail=0, period=128, buf=256
60.213654: applptr: pcmC0D0p/sub0: prev=2048, curr=2048, avail=0, period=128, buf=256
60.213796: hwptr: pcmC0D0p/sub0: POS: pos=0, old=1792, base=1792, period=128, buf=256
60.213800: applptr: pcmC0D0p/sub0: prev=2048, curr=2048, avail=0, period=128, buf=256
60.213937: applptr: pcmC0D0p/sub0: prev=2048, curr=2048, avail=0, period=128, buf=256
60.215356: hwptr: pcmC0D0p/sub0: IRQ: pos=128, old=1792, base=1792, period=128, buf=256
60.215542: applptr: pcmC0D0p/sub0: prev=2048, curr=2048, avail=128, period=128, buf=256
60.215679: hwptr: pcmC0D0p/sub0: POS: pos=128, old=1920, base=1792, period=128, buf=256
60.215683: applptr: pcmC0D0p/sub0: prev=2048, curr=2048, avail=128, period=128, buf=256
60.215813: applptr: pcmC0D0p/sub0: prev=2048, curr=2048, avail=128, period=128, buf=256
60.215947: applptr: pcmC0D0p/sub0: prev=2048, curr=2176, avail=0, period=128, buf=256
...
We can surely see 'applptr' event is probed even if the application run
for mmap programming scenario ('-M' option and 'hw' plugin). Below is a
result of strace:
02:44:15.886382 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0
02:44:15.887203 poll([{fd=4, events=POLLOUT|POLLERR|POLLNVAL}], 1, -1) = 1 ([{fd=4, revents=POLLOUT}])
02:44:15.887471 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0
02:44:15.887637 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0
02:44:15.887805 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0
02:44:15.887969 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0
02:44:15.888132 read(3, "..."..., 256) = 256
02:44:15.889040 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0
02:44:15.889221 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0
02:44:15.889431 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0
02:44:15.889606 poll([{fd=4, events=POLLOUT|POLLERR|POLLNVAL}], 1, -1) = 1 ([{fd=4, revents=POLLOUT}])
02:44:15.889833 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0
02:44:15.889998 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0
02:44:15.890164 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0
02:44:15.891048 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0
02:44:15.891228 read(3, "..."..., 256) = 256
02:44:15.891497 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0
02:44:15.891661 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0
02:44:15.891829 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0
02:44:15.891991 poll([{fd=4, events=POLLOUT|POLLERR|POLLNVAL}], 1, -1) = 1 ([{fd=4, revents=POLLOUT}])
02:44:15.893007 ioctl(4, SNDRV_PCM_IOCTL_SYNC_PTR, 0x56a32b30) = 0
We can see 7 calls of ioctl(2) with SNDRV_PCM_IOCTL_SYNC_PTR per loop with
call of poll(2). 128 PCM frames are transferred per loop of one poll(2),
because the PCM substream is configured with S16_LE format and 1 channel
(2 byte * 1 * 128 = 256 bytes). This equals to the size of period of PCM
buffer. Comparing to the probed data, one of the 7 calls of ioctl(2) is
actually used to commit the number of copied PCM frames to kernel space.
The other calls are just used to check runtime status of PCM substream;
e.g. XRUN.
The tracepoint event is useful to investigate this case. I note that below
modules are related to the above sample.
* snd-soc-dummy.ko
* snd-soc-imx-sgtl5000.ko
* snd-soc-fsl-ssi.ko
* snd-soc-imx-pcm-dma.ko
* snd-soc-sgtl5000.ko
My additional note is lock acquisition. The event is probed under acquiring
PCM stream lock. This means that calculation in the event is free from
any hardware events.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
In a series of recent work, ALSA PCM core got some arrangements to handle
application-side position on PCM buffer. However, relevant codes still
disperse to two translation units
This commit unifies these codes into a helper function.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
Many drivers bind the sequencer stuff in off-load by another driver
module, so that it's loaded only on demand. In the current code, this
mechanism doesn't work when the driver is built-in while the sequencer
is module. We check with IS_REACHABLE() and enable only when the
sequencer is in the same level of build.
However, this is basically a overshoot. The binder code
(snd-seq-device) is an individual module from the sequencer core
(snd-seq), and we just have to make the former a built-in while
keeping the latter a module for allowing the scenario like the above.
This patch achieves that by rewriting Kconfig slightly. Now, a driver
that provides the manual sequencer device binding should select
CONFIG_SND_SEQ_DEVICE in a way as
select SND_SEQ_DEVICE if SND_SEQUENCER != n
Note that the "!=n" is needed here to avoid the influence of the
sequencer core is module while the driver is built-in.
Also, since rawmidi.o may be linked with snd_seq_device.o when
built-in, we have to shuffle the code to make the linker happy.
(the kernel linker isn't smart enough yet to handle such a case.)
That is, snd_seq_device.c is moved to sound/core from sound/core/seq,
as well as Makefile.
Last but not least, the patch replaces the code using IS_REACHABLE()
with IS_ENABLED(), since now the condition meets always when enabled.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
At present, trace events are probed even if corresponding parameter is
not actually changed. This is inconvenient.
This commit improves the behaviour.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
When refining mask/interval parameters, helper functions can return error
code. This error is not handled immediately. This seems to return
parameters to userspace applications in its meddle of processing.
However, in general, when receiving error from system calls, the
application might not handle argument buffer. It's reasonable to
judge the above design as superfluity.
This commit handles the error immediately.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
Instead of the non-standard way to enable the build of snd-emux-synth
module inside Makefile, rewrite Kconfig to select the item explicitly
from each driver (sbawe and emu10k1). This is the standard way.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
This is a slightly intensive rewrite of Kconfig and Makefile about
ALSA sequencer stuff.
The first major change is that the kconfig items for the sequencer are
moved to sound/core/seq/Kconfig. OK, that's easy.
The substantial change is that, instead of hackish top-level module
selection in Makefile, we define a Kconfig item for each sequencer
module. The driver that requires such sequencer components select
exclusively the kconfig items. This is more straightforward and
standard way.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
Currently OSS sequencer emulation is tied with ALSA sequencer core,
both are built in the same level; i.e. when CONFIG_SND_SEQUENCER=y,
the OSS sequencer emulation is also always built-in, even though the
functionality can be built as an individual module.
This patch changes the rule and allows users to build snd-seq-oss
module while others are built-in. Essentially, it's just a few simple
changes in Kconfig and Makefile. Some driver codes like opl3 need to
convert from the simple ifdef to IS_ENABLED(). But that's all.
You might wonder how about the dependency: right, it can be messy, but
it still works. Since we rewrote the sequencer binding with the
standard bus, the driver can be bound at any time on demand. So, the
synthesizer driver module can be loaded individually from the OSS
emulation core before/after it.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
Currently CONFIG_SND_OSSEMUL is selected by each config like
CONFIG_SND_PCM_OSS. But, as see in the raw MIDI code that is built
conditionally with CONFIG_SND_OSSEMUL, we should rather make
CONFIG_SND_OSSEMUL user-selectable as the top kconfig item, and leave
the rest depending on it.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
Use the same print format of snd_pcm_debug_name() for userspace tracing
program.
Suggested-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
Results of ioctl(2) with SNDRV_PCM_IOCTL_HW_REFINE and
SNDRV_PCM_IOCTL_HW_PARAMS are different, because the latter has single
value for several parameters; e.g. channels of PCM substream. Selection
of the single value is done independently of application of constraints.
It's helpful for developers to trace the selection process.
This commit adds tracepoints to snd_pcm_hw_params_choose() for the
purpose.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
As of v4.12, snd_pcm_hw_params_choose() is just called in a process
context of ioctl(2) with SNDRV_PCM_IOCTL_HW_PARAMS. The function locates
in a different file, which has no tracepoints.
This commit moves the function to a file with the tracepoints for later
commit.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
snd_pcm_hw_constraint_list(), *_ratnums() and *_ratdens() receive the
const pointers. Constify the corresponding static objects for better
hardening.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
snd_pcm_hw_constraint_list(), *_ratnums() and *_ratdens() receive the
const pointers. Constify the corresponding static objects for better
hardening.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
snd_pcm_hw_constraint_list(), *_ratnums() and *_ratdens() receive the
const pointers. Constify the corresponding static objects for better
hardening.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
snd_pcm_hw_constraint_list(), *_ratnums() and *_ratdens() receive the
const pointers. Constify the corresponding static objects for better
hardening.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
snd_pcm_hw_constraint_list(), *_ratnums() and *_ratdens() receive the
const pointers. Constify the corresponding static objects for better
hardening.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
snd_pcm_hw_constraint_list(), *_ratnums() and *_ratdens() receive the
const pointers. Constify the corresponding static objects for better
hardening.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
snd_pcm_hw_constraint_list(), *_ratnums() and *_ratdens() receive the
const pointers. Constify the corresponding static objects for better
hardening.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
snd_pcm_hw_constraint_list(), *_ratnums() and *_ratdens() receive the
const pointers. Constify the corresponding static objects for better
hardening.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
snd_pcm_hw_constraint_list(), *_ratnums() and *_ratdens() receive the
const pointers. Constify the corresponding static objects for better
hardening.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
snd_pcm_hw_constraint_list(), *_ratnums() and *_ratdens() receive the
const pointers. Constify the corresponding static objects for better
hardening.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
snd_pcm_hw_constraint_list(), *_ratnums() and *_ratdens() receive the
const pointers. Constify the corresponding static objects for better
hardening.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
snd_pcm_hw_constraint_list(), *_ratnums() and *_ratdens() receive the
const pointers. Constify the corresponding static objects for better
hardening.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
snd_pcm_hw_constraint_list(), *_ratnums() and *_ratdens() receive the
const pointers. Constify the corresponding static objects for better
hardening.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
snd_pcm_hw_constraint_list(), *_ratnums() and *_ratdens() receive the
const pointers. Constify the corresponding static objects for better
hardening.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
snd_pcm_hw_constraint_list(), *_ratnums() and *_ratdens() receive the
const pointers. Constify the corresponding static objects for better
hardening.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
snd_pcm_hw_constraint_list(), *_ratnums() and *_ratdens() receive the
const pointers. Constify the corresponding static objects for better
hardening.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
snd_pcm_hw_constraint_list(), *_ratnums() and *_ratdens() receive the
const pointers. Constify the corresponding static objects for better
hardening.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
snd_pcm_hw_constraint_list(), *_ratnums() and *_ratdens() receive the
const pointers. Constify the corresponding static objects for better
hardening.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
snd_pcm_hw_constraint_list(), *_ratnums() and *_ratdens() receive the
const pointers. Constify the corresponding static objects for better
hardening.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
snd_pcm_hw_constraint_list(), *_ratnums() and *_ratdens() receive the
const pointers. Constify the corresponding static objects for better
hardening.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
snd_pcm_hw_constraint_list(), *_ratnums() and *_ratdens() receive the
const pointers. Constify the corresponding static objects for better
hardening.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
snd_pcm_hw_constraint_list(), *_ratnums() and *_ratdens() receive the
const pointers. Constify the corresponding static objects for better
hardening.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
snd_pcm_hw_constraint_list(), *_ratnums() and *_ratdens() receive the
const pointers. Constify the corresponding static objects for better
hardening.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
snd_pcm_hw_constraint_list(), *_ratnums() and *_ratdens() receive the
const pointers. Constify the corresponding static objects for better
hardening.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
snd_pcm_hw_constraint_list(), *_ratnums() and *_ratdens() receive the
const pointers. Constify the corresponding static objects for better
hardening.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
snd_pcm_hw_constraint_list(), *_ratnums() and *_ratdens() receive the
const pointers. Constify the corresponding static objects for better
hardening.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
snd_pcm_hw_constraint_list(), *_ratnums() and *_ratdens() receive the
const pointers. Constify the corresponding static objects for better
hardening.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
snd_pcm_hw_constraint_list(), *_ratnums() and *_ratdens() receive the
const pointers. Constify the corresponding static objects for better
hardening.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
snd_pcm_hw_constraint_list(), *_ratnums() and *_ratdens() receive the
const pointers. Constify the corresponding static objects for better
hardening.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
snd_pcm_hw_constraint_list(), *_ratnums() and *_ratdens() receive the
const pointers. Constify the corresponding static objects for better
hardening.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
snd_pcm_hw_constraint_list(), *_ratnums() and *_ratdens() receive the
const pointers. Constify the corresponding static objects for better
hardening.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
File size before:
text data bss dec hex filename
7126 240 0 7366 1cc6 sound/drivers/vx/vx_pcm.o
File size After adding 'const':
text data bss dec hex filename
7382 0 0 7382 1cd6 sound/drivers/vx/vx_pcm.o
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
File size before:
text data bss dec hex filename
2027 168 1 2196 894 sound/drivers/pcsp/pcsp_lib.o
File size After:
text data bss dec hex filename
2155 40 1 2196 894 sound/drivers/pcsp/pcsp_lib.o
Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
When drivers register no flags about information of PCM hardware, ALSA
PCM core fixups it roughly. Currently, this operation places in a
function snd_pcm_hw_refine(). It can be moved to a function
fixup_unreferenced_params() because it doesn't affects operations
between these two functions.
This idea is better to bundle codes with similar purposes and this commit
achieves it.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
A structure for parameters of PCM runtime has parameters which are
not classified as mask/interval type. They are decided only when
corresponding normal parameters have unique values.
* struct snd_pcm_hw_params.msbits
* struct snd_pcm_hw_params.rate_num
* struct snd_pcm_hw_params.rate_den
* struct snd_pcm_hw_params.fifo_size
Current implementation of hw_params ioctl sometimes doesn't decide these
parameters even if corresponding parameters are fixed, because these
parameters are evaluated before a call of snd_pcm_hw_params_choose().
This commit adds a helper function to process the parameters and call it
in proper positions.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
To fixup some parameters, ALSA PCM core refers the other parameters as
constants. There're some macros for this purpose.
This commit replaces codes with them.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
|
Drivers add rules of parameters to runtime of PCM substream, when
applications open ALSA PCM character device. When applications call
ioctl(2) with SNDRV_PCM_IOCTL_HW_REFINE or SNDRV_PCM_IOCTL_HW_PARAMS, the
rules are applied to the parameters and return the result to user space.
The rule can have dependency between parameters. Additionally, it can have
condition flags about application of rules. Userspace applications can
indicate the flags to suppress change of parameters.
This commit attempts to describe the mechanism.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
|
Takashi Sakamoto
Takashi Iwai
Arvind Yadav