In ALSA control interface in asound.h, 'struct snd_ctl_elem_info' has
'dimen' member to deliver information for multi-dimensional array, however
there's no common way to handle the member. As a result, drivers can
force userspace applications to handle the information by inconsistent
ways.
This issue was reported by a commit 51db452df07b ('Revert "ALSA: echoaudio:
purge contradictions between dimension matrix members and total number of
members"') to Linux kernel. As a result of discussion at Linux
miniconference 2017, usage of 'dimen' member of 'struct snd_ctl_elem_info'
is going to be deprecated for future removal.
A removal of kernel interface can cause regression issues. However no ALSA
driver in kernel land except for 'echoaudio' series utilizes this feature.
Actually it's reasonable to assume that 'echomixer' program is an unique
consumer of the interface in user land and the removal rarely brings any
impact to user land.
This commit deprecates some APIs corresponding to the kernel interface. The
kernel interface is kept till Linux kernel v4.20 at least, but actual
timing of removal is not fixed yet. After that, these APIs may also be
removed at a reasonable timing.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
The snd_ctl_ext_callback::read_event() callback is only optional
if no poll descriptor was given via
snd_ctl_ext_t::poll_fd
or
snd_ctl_ext_callback::snd_ctl_ext_poll_descriptors().
If a poll descriptor is given the
snd_ctl_ext_callback::read_event()
callback has also to be defined
because there is no minigful default behavior.
This callback will be called when ever the poll() on
the file descriptor indicates that there is an event pending.
Therefore returning a 0 which indicates that there is no event makes no
sense.
Signed-off-by: Timo Wischer <twischer@de.adit-jv.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
According POSIX[1] and linux manpage[2] the include is poll.h, not
sys/poll.h.
This fixes the he following compiler warning when build with musl libc:
/usr/include/sys/poll.h:1:2: warning: #warning redirecting incorrect #include <sys/poll.h> to <poll.h> [-Wcpp]
#warning redirecting incorrect #include <sys/poll.h> to <poll.h>
^~~~~~~
Signed-off-by: Natanael Copa <ncopa@alpinelinux.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
From my misunderstanding, some explanations are wrong. This commit
corrects them.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
The documentation gives no hints to users about format of TLV data.
This commit add hints to construct/parse the information.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
A commit fe1b08803d ("ctl: improve API documentation for threshold level
operations") changes documentations for some TLV-related APIs with wrong
explanations.
This commit fix it with better explanations.
Fixes: fe1b08803d ("ctl: improve API documentation for threshold level operations")
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Usage of assert() is not better practice of programming as shared library
APIs. They should return appropriate error code to promote applications to
handle error state.
This commit applies condition statements with return value of -EINVAL,
instead of assert(). As a backward compatibility for existent applications,
old APIs still call assert().
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
In this development period, some APIs have already been added. Most of
them are to add an element set, while their names are not so appropriate
against their feature. This is due to following to names of old APIs.
This commit renames them.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
I forgot it when committing to the API.
Fixes: 16812b70daeb('ctl: add an API to set dimension levels to element information')
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
In ALSA control core, when several events occurs for an element, they're
represented bit mask (struct snd_ctl_event.data.elem.mask). Thus userspace
applications can handles these events separately in one I/O operation.
There's an exception; removal event. This is represented by all of bits in
the mask. Therefore, when a removal event occurs for an element, all of
queued events for the element are overwritten.
This works worse for a combination of applications which add/remove control
elements and applications which keep a cache of elements. For example,
let's assume a case that:
1.some elements are added by ioctl(SNDRV_CTL_IOCTL_ELEM_ADD).
2.ALSA control core handles the request and queues 'add' event.
3.applications don't read the event yet.
4.the elements are removed by ioctl(SNDRV_CTL_IOCTL_ELEM_REMOVE)
5.ALSA control core handles the request and queues 'removal' event by
overwriting queued events.
6.applications read the event at last.
7.the applications cannot find removed elements in their cache data.
Especially, when applications use hctl interface of ALSA userspace library,
this situation occurs because the interface is designed to keep element
cache implicitly inner the library. PulseAudio is such an application. When
executing a test program of ALSA library (test/user-ctl-element-set.c),
pulseaudio process aborts due to assertion at calls of
snd_hctl_handle_events().
The rule to represent events is in ALSA kernel/userspace interfaces
(UAPI header) and it's difficult to improve the rule. Therefore,
developers should pay enough attention to the fact that userspace
applications can receive removal events for elements which are not
notified with 'add' event.
For this reason, this commit removes assertion from event handler of ALSA
hctl API.
CC: pulseaudio-discuss@lists.freedesktop.org
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Currently, documentation of APIs to add an element set describes causes of
errors partly. But it gives an opinion to describe them thoroughly. This
is not good for users.
This commit changes the documentation so that it partly describes the
causes.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Linux 4.7 or former have no validator of dimension information. This can
causes an issue related to user-defined element set. For example, When
calculated total members in multi-dimensional matrix is larger than actual
capacity of snd_ctl_elem_value_t, processes to handle the element can
cause buffer-over-run.
For backward portability of this userspace library, this commit adds a
validator of dimension information. When userspace applications give
invalid dimension information to APIs to add element set, they receive
-EINVAL.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
In a former commit, 'struct snd_ctl_elem_info' is used as a 'container' to
transfer extra fields of element information for APIs to add an element
set. The extra fields should be filled in advance of call of the APIs.
Currently, dimension level is in the extra fields and no APIs to set it.
This commit adds an API to set dimension level to the information
structure. This API is expected to be used in advance of usage of APIs
to add an element set, for nothing others. When the information structure
is extended in future, then the similar APIs shall be added for the new
feature.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
In ALSA control feature, information of an element includes extra fields
to type-specific parameters; i.e. dimension. The fields can be extended in
future.
Meanwhile, current APIs to add user-defined element set can not support
such an extended fields. This may cause inconveniences in future.
This commit supports the fields, by changing APIs for element set.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Second argument of these functions has three different names in
documentation/header/code (obj/control/value). This easily causes users'
confusion.
This commit applies consistent names for the arguments.
Fixes: 90020c05f8 ('ctl: improve comments for handling element data')
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Inner this library, layouts of all structures are public. At a compilation
time, each size of the structures can be calculated. It means that we can
use automatic variable instead of calling alloca(3) to program this
library because in both ways storages are kept on stack frame of process
VMA. Besides, the usage of automatic variables requires less instructions
than calls of alloca(3). Furthermore, alloca(3) is not described in any
C language standards.
This commit replaces calls of alloca(3) just for structures with automatic
variables, for control features.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
In ALSA kernel/userspace interfaces, 'struct snd_ctl_elem_info' has a
'dimension' parameter. This parameter consists of an array with four
elements. Each element represents the number of members in corresponding
dimension level to construct matrix.
In current implementation, a get function, 'snd_ctl_elem_info_get_dimension()'
is hardcoded to return zero to level 4, against actual value. This commit fixes
the bug.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
In alsa-lib, threshold level operations require an array of unsigned-int
members, while there's little explanation about how to fill it. To usual
developers such as me, they're quite hard to understand.
This commit adds a few comment for easy understanding about how to use
the APIs.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
ALSA ctl feature includes threshold level feature. This is introduced in
2006, and there's little resources about it.
This commit adds a simple explanation about the feature.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
In former commit, userspace library gets some APIs for element set. Some
existed functions can be simple wrappers of them.
This commit changes these APIs as wrapper functions. Additionally, this
commit also adds local variables for identical information of elements.
This modification is important to keep API consistency.
Some old APIs to add an element have id variables with const type
qualifier, while some new APIs to add element set changes the content of
given parameters. This comes from a change in Linux kernel 4.1.
In this commit [1], in-kernel implementation fills all fields of identical
data in userspace. As a result, when adding a new element set, userspace
applications can get an identical data for the first element in the set.
This lost the semantics of const type qualifier in userspace.
[1] http://git.kernel.org/cgit/linux/kernel/git/tiwai/sound.git/commit/sound/core?id=cab2ed7474bffafd2a68a885e03b85526194abcd
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
In ALSA control core, it's not allowed to an element set of IEC 958 type
to have several elements. Therefore, consecutive patchset doesn't touch an
API to add an element of IEC958 type. However, it's better to supplement
comments for the API.
This commit do it.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
ALSA control core allows userspace applications to add an element set.
However, in ALSA userspace library, there's no APIs enough to utilize
the feature. The library has APIs just to add an element set with a single
element.
This commit adds functions to add an element set with several elements.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Some parts of control API documentation are described with core-developer
friendly explanations. To usual developer such as me, they're quite hard
to understand.
This commit improves such comments for a part of APIs to handle data of
each element.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit adds a description about the design of ALSA control interface
for developers to understand a few components of low level.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Most of open functions in alsa-lib have the call pattern:
snd_config_update();
return snd_xxx_open(x, snd_config, ...);
This means that the toplevel config gets updated, and passed to a
local open function. Although snd_config_update() itself has a
pthread mutex to be thread safe, the whole procedure above isn't
thread safe. Namely, the global snd_config tree may be deleted and
recreated at any time while the open function is being processed.
This may lead to a data corruption and crash of the program.
For avoiding the corruption, this patch introduces a refcount to
config tree object. A few new helper functions are introduced as
well:
- snd_config_update_ref() does update and take the refcount of the
toplevel tree. The obtained config tree has to be freed via
snd_config_unref() below.
- snd_config_ref() and snd_config_unref() manage the refcount of the
config object. The latter eventually deletes the object when all
references are gone.
Along with these additions, the caller of snd_config_update() and
snd_config global tree in alsa-lib are replaced with the new helpers.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
When a hint description has only either device_input or device_output,
we shouldn't handle it as a full duplex but rather a single
direction. In that way, we can avoid to list up a playback stream
like dmix or surround51 as a capture stream in the namehint.
Reported-by: Trent Reed <treed0803@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
In most codes for control APIs, assertions are used to check given
arguments from applications. If the arguments are not expected, the
application is forced to abort. When NDEBUG is defined in the beginning
of the codes, no checks are performed.
Although, in snd_ctl_elem_set_bytes(), assertion is used with condition
statement. There's an intention to check the arguments regardless of
NDEBUG. However, this is not the same fashion in the codes.
This commit applies the same fashion to the function, to keep consistent
usage of assertion.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
In ALSA control core, there're two ways to identify elements. One is by
numid. Another is by name/index. The former way is lighter than the latter
way.
In control API, after adding elements by snd_ctl_elem_add_integer() and
snd_ctl_elem_add_integer64(), these functions initialize value of each
channel. When executing this operation, used ID information is still given
by applications. Although, in this time, the element can be identified
according to numid.
This commit uses the numid instead of name/index pair.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
In UAPI of asound.h, there're 6 types of control element; boolean, integer,
enumerated, bytes, iec958 and integer64 (The none type seems to be added to
start the value at non-zero). Although, current description in alsa-lib
has a lack of integer64 type.
This commit fulfil the type.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Improve the parser to allow empty elements followed by a comma.
Now amixer works like below for setting only the third element.
% amixer cset 'IIR1 Band1' ,,200
Reported-and-tested-by: Arun Raghavan <arun@accosted.net>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Like pcm and rawmidi, each object parser needs to accept the hint
component. Now a new local function _snd_conf_generic_id() was
introduced to replace each call of "comment" and "type" field checks.
Also, the two existing identical functions for pcm and rawmidi are
removed and the new function is used commonly.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Due to the uninitialized field before the error path, passing an
invalid iface argument may result in a bad free() call. Initialize
the fields properly beforehand.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
The current code of snd_device_name_hint() has a bug when listing up
devices without the device index (e.g. ctl). Because it assigns the
default device index 0 unconditionally and it has a check at the later
point to filter entries with dev >= 0, it ended up with empty
outputs.
The fix is simply to remove the bogus assignment of dev = 0.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
snd_device_name_hint() tries to free the allocated list at the error
path via snd_device_name_free_hint(). But snd_device_name_free_hint()
expects a list terminated by NULL while snd_device_name_hint() doesn't
add it. Adding it may again result in an error and thus isn't
guaranteed to work. Hence we can't add NULL at the error path.
Instead, now the code always allocates one entry more, and zero-clears
the newly allocated beforehand to guarantee the NULL termination.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
When minus value is given as a parameter, the API returns whether
the caller has already subscribed or not.
This commit adds a comment about this so as better documentation.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
PCM and control shm plugins and aserver have some codes to resolve the
host address and check whether it's a local host although the given
address is never used. In addition, the code contains gethostbyname()
that is known to be obsoleted. So, let's get rid of all these unused
codes.
The host configuration item is still accepted (but just ignored) for
keeping the compatibility.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Use zero-base for strtol(), so get_integer() and get_integer64()
can parse decimal, octal and hexadecimal data from input string.
Signed-off-by: Lu, Han <han.lu@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
- rename configure.in to configure.ac
- replace INCLUDES with AM_CPPFLAGS
- modernize AM_INIT_AUTOMAKE invocation
Signed-off-by: Patrick Welche <prlw1@cam.ac.uk>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Currently, for a TLV consisting of TLV_DB_SCALE_ITEMs, if e.g. alsamixer
calls snd_mixer_selem_set_playback_dB() with a value that is in-between
two TLV_DB_SCALE_ITEMs, and xdir is negative, the selected raw hardware
value is the minimum in the first range above that value, rather than the
maximum in the last range below that value.
The user-visible symptom is that in alsamixer, pressing the down key to
reduce the value sticks at certain points, and cannot be incrementally
reduced any further, although directly selecting a much lower value (e.g.
by pressing 0..9) works as expected. This is triggered e.g. by
sound/soc/codec/max98090.c's max98090_hp_tlv[].
Fix this by checking whether xdir is positive or not, rather than
checking whether it has a non-zero value. The code to select the previous
range's max value is already present. This matches how xdir is used in
other parts of the code.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Sometimes a hook manipulates the config tree, which makes currently
running iterators point to freed memory. As a workaround, make two
copies, one for the iterators and another for the hooks.
BugLink: https://bugs.launchpad.net/bugs/1008600
Signed-off-by: David Henningsson <david.henningsson@canonical.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Add --with-max-cards option to specify the max number of cards in
configure script, when the support for more than 32 cards is
required.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Upon an interrupt, it is necessary to abort the wait loops with the EINTR
error code. Introduce snd_*_abort() functions to handle this case.
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
When both an SPDIF and an HDMI output are present on HD-audio, both
try to access IEC958 controls with index=0 although one of them must
be wrong. For avoiding this conflict, the recent kernel code (3.9 and
3.8 stable) moves the IEC958 controls of an SPDIF with index=16 once
when the conflict happens.
In this patch, the corresponding support is added in alsa-lib side.
The new "skip_rest" boolean flag is added to the hooked element
definition which indicates that the rest of element array will be
ignored once when this element is present and evaluated. With this
new flag, the HD-audio config takes index=16 primarily, then take
index=0 as fallback.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
