177 Commits
Author SHA1 Message Date
Cássio GabrielandTakashi Iwai 98fb1c1bb1 ALSA: firewire-motu: Protect register DSP event queue positions
The register DSP event queue is updated under parser->lock, but
snd_motu_register_dsp_message_parser_count_event() reads pull_pos and
push_pos without the lock.
snd_motu_register_dsp_message_parser_copy_event() also reads both queue
positions before taking the lock.

Protect these accesses with parser->lock as well. This keeps the hwdep
poll/read path consistent with the producer side and with the cached
meter/parameter accessors.

Fixes: 634ec0b290 ("ALSA: firewire-motu: notify event for parameter change in register DSP model")
Cc: stable@vger.kernel.org
Signed-off-by: Cássio Gabriel <cassiogabrielcontato@gmail.com>
Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20260521-alsa-firewire-motu-event-locking-v1-1-708e1c2b5e56@gmail.com
2026-05-25 09:19:44 +02:00
Linus Torvalds bf4afc53b7 Convert 'alloc_obj' family to use the new default GFP_KERNEL argument
This was done entirely with mindless brute force, using

    git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
        xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'

to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.

Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.

For the same reason the 'flex' versions will be done as a separate
conversion.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-21 17:09:51 -08:00
Kees Cook 69050f8d6d treewide: Replace kmalloc with kmalloc_obj for non-scalar types
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:

Single allocations:	kmalloc(sizeof(TYPE), ...)
are replaced with:	kmalloc_obj(TYPE, ...)

Array allocations:	kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with:	kmalloc_objs(TYPE, COUNT, ...)

Flex array allocations:	kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with:	kmalloc_flex(*PTR, FAM, COUNT, ...)

(where TYPE may also be *VAR)

The resulting allocations no longer return "void *", instead returning
"TYPE *".

Signed-off-by: Kees Cook <kees@kernel.org>
2026-02-21 01:02:28 -08:00
Junrui LuoandTakashi Iwai 298e753880 ALSA: firewire-motu: add bounds check in put_user loop for DSP events
In the DSP event handling code, a put_user() loop copies event data.
When the user buffer size is not aligned to 4 bytes, it could overwrite
beyond the buffer boundary.

Fix by adding a bounds check before put_user().

Suggested-by: Takashi Iwai <tiwai@suse.de>
Fixes: 634ec0b290 ("ALSA: firewire-motu: notify event for parameter change in register DSP model")
Signed-off-by: Junrui Luo <moonafterrain@outlook.com>
Link: https://patch.msgid.link/SYBPR01MB788112C72AF8A1C8C448B4B8AFA3A@SYBPR01MB7881.ausprd01.prod.outlook.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2025-12-09 08:08:02 +01:00
Junrui LuoandTakashi Iwai 210d77cca3 ALSA: firewire-motu: fix buffer overflow in hwdep read for DSP events
The DSP event handling code in hwdep_read() could write more bytes to
the user buffer than requested, when a user provides a buffer smaller
than the event header size (8 bytes).

Fix by using min_t() to clamp the copy size, This ensures we never copy
more than the user requested.

Reported-by: Yuhao Jiang <danisjiang@gmail.com>
Reported-by: Junrui Luo <moonafterrain@outlook.com>
Fixes: 634ec0b290 ("ALSA: firewire-motu: notify event for parameter change in register DSP model")
Signed-off-by: Junrui Luo <moonafterrain@outlook.com>
Link: https://patch.msgid.link/SYBPR01MB78810656377E79E58350D951AFD9A@SYBPR01MB7881.ausprd01.prod.outlook.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2025-12-05 15:25:55 +01:00
Takashi Iwai 914c62f218 ALSA: firewire: motu: Use guard() for spin locks
Clean up the code using guard() for spin locks.

Merely code refactoring, and no behavior change.

Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://patch.msgid.link/20250830080351.25600-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2025-08-30 10:04:22 +02:00
Takashi Iwai b9ac651964 ALSA: firewire: motu: Use guard() for mutex locks
Replace the manual mutex lock/unlock pairs with guard() for code
simplification.

Only code refactoring, and no behavior change.

Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20250828132802.9032-6-tiwai@suse.de
2025-08-30 10:02:21 +02:00
Takashi SakamotoandTakashi Iwai aea3493246 ALSA: firewire-motu: drop EPOLLOUT from poll return values as write is not supported
The ALSA HwDep character device of the firewire-motu driver incorrectly
returns EPOLLOUT in poll(2), even though the driver implements no operation
for write(2). This misleads userspace applications to believe write() is
allowed, potentially resulting in unnecessarily wakeups.

This issue dates back to the driver's initial code added by a commit
71c3797779 ("ALSA: firewire-motu: add hwdep interface"), and persisted
when POLLOUT was updated to EPOLLOUT by a commit a9a08845e9 ('vfs: do
bulk POLL* -> EPOLL* replacement("").').

This commit fixes the bug.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://patch.msgid.link/20250829233749.366222-1-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2025-08-30 09:32:45 +02:00
Takashi Iwai 97f5468381 ALSA: firewire: motu: Use safer strscpy() instead of strcpy()
Use a safer function strscpy() instead of strcpy() for copying to
arrays.

Only idiomatic code replacement, and no functional changes.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://patch.msgid.link/20250710100727.22653-20-tiwai@suse.de
2025-07-11 09:52:57 +02:00
Takashi Sakamoto 5c49cc0ed4 ALSA: firewire: use nonatomic PCM operation
In the former commits, the callback of isochronous context runs on usual
work process. In the case, ALSA PCM device has a flag, nonatomic, to
acquire mutex lock instead of spin lock for PCM substream group.

This commit uses the flag. It has an advantage in the case that ALSA PCM
application uses the large size of intermediate buffer, since it takes
too long time even in tasklet softIRQ to process many of isochronous
packets, then result in the delay of system event due to disabled IRQ so
long. It is avertible to switch to nonatomic operation.

Reviewed-by: Takashi Iwai <tiwai@suse.de>
Tested-by: Edmund Raile <edmund.raile@protonmail.com>
Link: https://lore.kernel.org/r/20240904125155.461886-6-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2024-09-04 21:51:54 +09:00
Takashi Iwai fdd51b3e73 ALSA: firewire: Use *-y instead of *-objs in Makefile
*-objs suffix is reserved rather for (user-space) host programs while
usually *-y suffix is used for kernel drivers (although *-objs works
for that purpose for now).

Let's correct the old usages of *-objs in Makefiles.

Cc: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20240507135513.14919-8-tiwai@suse.de
2024-05-08 18:18:03 +02:00
Takashi SakamotoandTakashi Iwai 6d5a2dda9b ALSA: firewire-motu: add support for MOTU 896 mk3 FireWire and Hybrid
Mark of the Unicorn released 896 mk3 FireWire in 2008 as part of the third
generation of its FireWire series. In 2011, 896 mk3 hybrid was released to
support USB protocol.

It supports sampling transfer frequency up to 192.0 kHz. The packet
format differs depending on both of current sampling transfer frequency
and the type of signal in optical interfaces. The model supports
transmission of PCM frames as well as MIDI messages.

The 896 mk3 FireWire consists of below ICs:

 * Texas Instruments TSB41AB2
 * Xilinx Spartan-3A FPGA, XC3S500E
 * Texas Instruments TMS320C6722
 * Microchip (Atmel) AT91SAM SAM7S256

It supports sampling transfer frequency up to 192.0 kHz. The packet
format differs depending on both of current sampling transfer frequency
and the type of signal in two pairs of optical interfaces. The model
supports transmission of PCM frames, while has no port for MIDi messages.

The model supports command mechanism to configure internal DSP. Hardware
meter information is available in the first 2 chunks of each data block
of tx packet.

This commit adds support for it. The 896 mk3 FireWire is just tested, but
the 896 mk3 Hybrid is not yet.

$ config-rom-pretty-printer < motu-896mk3fw.img
               ROM header and bus information block
               -----------------------------------------------------------------
1024  04100ce1  bus_info_length 4, crc_length 16, crc 3297
1028  31333934  bus_name "1394"
1032  20ff7000  irmc 0, cmc 0, isc 1, bmc 0, cyc_clk_acc 255, max_rec 7 (256)
1036  0001f200  company_id 0001f2     |
1040  00093add  device_id 0000604893  | EUI-64 0547556791237341

               root directory
               -----------------------------------------------------------------
1044  0004ef04  directory_length 4, crc 61188
1048  030001f2  vendor
1052  0c0083c0  node capabilities: per IEEE 1394
1056  d1000002  --> unit directory at 1064
1060  8d000005  --> eui-64 leaf at 1080

               unit directory at 1064
               -----------------------------------------------------------------
1064  0003998d  directory_length 3, crc 39309
1068  120001f2  specifier id
1072  13000017  version
1076  17101800  model

               eui-64 leaf at 1080
               -----------------------------------------------------------------
1080  0002cc82  leaf_length 2, crc 52354
1084  0001f200  company_id 0001f2     |
1088  00093add  device_id 0000604893  | EUI-64 0547556791237341

$ config-rom-pretty-printer < motu-896mk3hybrid.img
               ROM header and bus information block
               -----------------------------------------------------------------
1024  04103cbe  bus_info_length 4, crc_length 16, crc 15550
1028  31333934  bus_name "1394"
1032  20ff7000  irmc 0, cmc 0, isc 1, bmc 0, cyc_clk_acc 255, max_rec 7 (256)
1036  0001f200  company_id 0001f2     |
1040  000ae601  device_id 0000714241  | EUI-64 0547556791346689

               root directory
               -----------------------------------------------------------------
1044  0004ef04  directory_length 4, crc 61188
1048  030001f2  vendor
1052  0c0083c0  node capabilities: per IEEE 1394
1056  d1000002  --> unit directory at 1064
1060  8d000005  --> eui-64 leaf at 1080

               unit directory at 1064
               -----------------------------------------------------------------
1064  000394ac  directory_length 3, crc 38060
1068  120001f2  specifier id
1072  13000037  version
1076  17102800  model

               eui-64 leaf at 1080
               -----------------------------------------------------------------
1080  0002cf69  leaf_length 2, crc 53097
1084  0001f200  company_id 0001f2     |
1088  000ae601  device_id 0000714241  | EUI-64 0547556791346689

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20240129022711.254383-1-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2024-01-29 09:04:30 +01:00
Takashi Iwai ea77850e98 ALSA: firewire: Fix -Wformat-truncation warning for MIDI stream names
The compile warnings at filling MIDI stream name strings are all
false-positive; the number of streams can't go so high.

For suppressing the warning, replace snprintf() with scnprintf().
As stated in the above, truncation doesn't matter.

Link: https://lore.kernel.org/r/20230915082802.28684-12-tiwai@suse.de
Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Tested-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2023-09-15 13:22:06 +02:00
Takashi SakamotoandTakashi Iwai 81c2943507 ALSA: firewire: use 'GPL' string for module license contributed by Takashi Sakamoto
In MODULE_LICENSE macro, "GPL" string obsoletes "GPL v2" string by a
commit bf7fbeeae6 ("module: Cure the MODULE_LICENSE "GPL" vs. "GPL v2"
bogosity").

This commit uses the preferable expression.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20230611144445.221529-2-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2023-06-12 14:38:58 +02:00
Takashi Iwai 5661706efa Merge branch 'topic/apple-gmux' into for-next
Pull vga_switcheroo fix for Macs

Signed-off-by: Takashi Iwai <tiwai@suse.de>
2023-02-16 14:18:54 +01:00
Takashi SakamotoandTakashi Iwai c7a806d9ce ALSA: firewire-motu: fix unreleased lock warning in hwdep device
Smatch static analysis tool detects that acquired lock is not released
in hwdep device when condition branch is passed due to no event. It is
unlikely to occur, while fulfilling is preferable for better coding.

Reported-by: Dan Carpenter <error27@gmail.com>
Fixes: 634ec0b290 ("ALSA: firewire-motu: notify event for parameter change in register DSP model")
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20230130141540.102854-1-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2023-01-31 09:34:04 +01:00
Takashi SakamotoandTakashi Iwai 7fc693e474 ALSA: firewire-lib: obsolete return value from context payload processing layer
This commit obsoletes return value from the context payload processing layer
since the multiplier between the data block count and PCM frame count was
moved to the packet streaming processing layer.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20230110134933.322794-3-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2023-01-12 12:14:50 +01:00
Takashi SakamotoandTakashi Iwai a36183f69c ALSA: firewire-lib: move parameter for pcm frame multiplier from context payload processing layer
The current implementation delegates the task to calculate the number of
processed PCM frames into the context payload processing layer. It looks
good as long as frame calculation is done for a single purpose.
Nevertheless, another purpose, the computation of extra delay for the
runtime of PCM substream, requires frame calculation, too.

This commit refactors the current implementation so that the packet stream
processing layer is responsible for the calculation of PCM frame, too. The
member is moved to stream structure for multiplier between data block
count and PCM frame count.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20230110134933.322794-2-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2023-01-12 12:14:49 +01:00
Takashi SakamotoandTakashi Iwai 0cac60c776 ALSA: firewire-lib: use circular linked list for context payload processing layer
The list of packet descriptor is passed to context payload processing
layer so that each driver can copy PCM frames, MIDI messages, and device
specific data between packet payload buffer and intermediate buffer for
user space application.

The list of packet descriptor was replaced by circular linked list in a
previous commit. This commit uses circular linked in context payload
processing layer as well.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20230109021738.75543-3-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2023-01-09 17:04:44 +01:00
Takashi Iwai 23cb0767f0 ALSA: firewire: Replace runtime->status->state reference to runtime->state
The recent change in ALSA core allows drivers to get the current PCM
state directly from runtime object.  Replace the calls accordingly.

Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20220926135558.26580-5-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2022-09-27 08:47:25 +02:00
Christophe JAILLETandTakashi Iwai 1dd0dd0b1f ALSA: firewire: Remove some left-over license text in sound/firewire
There is already a SPDX-License-Identifier tag, so the corresponding license
text can be removed.

While at it, be more consistent and:
  - add a missing .c (ff-protocol-latter)
  - remove an empty line (motu-protocol-v1)

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/2bfe76c7eeb0f5205a1427e280bf8d9da0354a62.1664110649.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2022-09-27 08:42:18 +02:00
Takashi SakamotoandTakashi Iwai 411ac2982c ALSA: firewire-motu: add support for MOTU Track 16
Mark of the Unicorn designed Track 16 2011 as one of models in third
generation of its FireWire series. The model is already discontinued.
It consists of below ICs:

 * Texas Instruments TSB41AB1
 * Microchip (SMSC) USB3300
 * Xilinx Spartan-3A FPGA, XC3S700A
 * Texas Instruments TMS320C6722
 * Microchip (Atmel) AT91SAM SAM7S512

It supports sampling transfer frequency up to 192.0 kHz. The packet
format differs depending on both of current sampling transfer frequency
and the type of signal in optical interfaces. The model supports
transmission of PCM frames as well as MIDI messages.

The model supports command mechanism to configure internal DSP. Hardware
meter information is available in the first 2 chunks of each data block
of tx packet.

This commit adds support for it.

$ cd linux-firewire-tools/src
$ python crpp < /sys/bus/firewire/devices/fw1/config_rom
               ROM header and bus information block
               -----------------------------------------------------------------
400  04107d95  bus_info_length 4, crc_length 16, crc 32149
404  31333934  bus_name "1394"
408  20ff7000  irmc 0, cmc 0, isc 1, bmc 0, cyc_clk_acc 255, max_rec 7 (256)
40c  0001f200  company_id 0001f2     |
410  000a83c4  device_id 00000a83c4  | EUI-64 0001f200000a83c4

               root directory
               -----------------------------------------------------------------
414  0004ef04  directory_length 4, crc 61188
418  030001f2  vendor
41c  0c0083c0  node capabilities per IEEE 1394
420  d1000002  --> unit directory at 428
424  8d000005  --> eui-64 leaf at 438

               unit directory at 428
               -----------------------------------------------------------------
428  00035b04  directory_length 3, crc 23300
42c  120001f2  specifier id
430  13000039  version
434  17102800  model

               eui-64 leaf at 438
               -----------------------------------------------------------------
438  0002b25f  leaf_length 2, crc 45663
43c  0001f200  company_id 0001f2     |
440  000a83c4  device_id 00000a83c4  | EUI-64 0001f200000a83c4

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20211107110644.23511-1-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-11-08 13:49:27 +01:00
Takashi SakamotoandTakashi Iwai bf868be7a2 ALSA: firewire-motu: add support for MOTU Traveler mk3
Mark of the Unicorn (MOTU) shipped Traveler mk3 as one of models in third
generation of its FireWire series, and discontinued it already. The model
consists of below ICs:

 * Texas Instruments TSB41AB2
 * Phillips Semiconductors PDI1394L40
 * Altera cyclone EP1C3
 * Texas Instruments TMS320VC5402

It supports sampling transfer frequency up to 192.0 kHz. The packet
format differs depending on both of current sampling transfer frequency
and whether to enable ADAT channels in rx/tx packets. The model supports
transmission of PCM frames as well as MIDI messages.

The model supports command mechanism to configure internal DSP. Hardware
meter information is available in the first 2 chunks of each data block
of tx packet.

This commit adds support for it.

$ cd linux-firewire-tools/src
$ python crpp < /sys/bus/firewire/devices/fw1/config_rom
               ROM header and bus information block
               -----------------------------------------------------------------
400  0410af0a  bus_info_length 4, crc_length 16, crc 44810
404  31333934  bus_name "1394"
408  20ff7000  irmc 0, cmc 0, isc 1, bmc 0, cyc_clk_acc 255, max_rec 7 (256)
40c  0001f200  company_id 0001f2     |
410  00090911  device_id 0000090911  | EUI-64 0001f20000090911

               root directory
               -----------------------------------------------------------------
414  0004ef04  directory_length 4, crc 61188
418  030001f2  vendor
41c  0c0083c0  node capabilities per IEEE 1394
420  d1000002  --> unit directory at 428
424  8d000005  --> eui-64 leaf at 438

               unit directory at 428
               -----------------------------------------------------------------
428  00031733  directory_length 3, crc 5939
42c  120001f2  specifier id
430  1300001b  version
434  17102800  model

               eui-64 leaf at 438
               -----------------------------------------------------------------
438  00028484  leaf_length 2, crc 33924
43c  0001f200  company_id 0001f2     |
440  00090911  device_id 0000090911  | EUI-64 0001f20000090911

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20211104110627.94469-1-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-11-04 16:32:19 +01:00
Takashi SakamotoandTakashi Iwai 2672e1970a ALSA: firewire-motu: remove TODO for interaction with userspace about control message
Now UAPI of ALSA firewire stack got enough functions to interact with
userspace for protocol of MOTU FireWire series. Let's remove the relevant
TODO.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20211029012847.11839-1-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-10-29 10:01:43 +02:00
Takashi SakamotoandTakashi Iwai 407359d44e ALSA: firewire-motu: export meter information to userspace as float value
In command DSP models, one meter information consists of 4 bytes for
IEEE 764 floating point (binary32). In previous patch, it is exported
to userspace as 32 bit storage since the storage is also handled in
ALSA firewire-motu driver as well in kernel space in which floating point
arithmetic is not preferable. On the other hand, ALSA firewire-motu driver
doesn't perform floating point calculation. The driver just gather meter
information from isochronous packets and fill structure fields for
userspace.

In 'header' target of Kbuild, UAPI headers are processed before installed.
In this timing, #ifdef macro with __KERNEL__ is removed. This mechanism
is useful in the case so that the 32 bit storage can be accessible as u32
type in kernel space and float type in user space. We can see the same
usage in ''struct acct_v3' in 'include/uapi/linux/acct.h'.

This commit is for the above idea. Additionally, due to message
protocol, meter information is filled with 0xffffffff in the end of
period but 0xffffffff is invalid as binary32. To avoid confusion in
userspace application, the last two elements are left without any
assignment.

Suggested-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20211027125529.54295-4-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-10-28 09:10:41 +02:00