1
Commit Graph

5 Commits

Author SHA1 Message Date
Karol Kosik
6aa8700150 ALSA: usb-audio: Support multiple control interfaces
Registering Numark Party Mix II fails with error 'bogus bTerminalLink 1'.
The problem stems from the driver not being able to find input/output
terminals required to configure audio streaming. The information about
those terminals is stored in AudioControl Interface. Numark device
contains 2 AudioControl Interfaces and the driver checks only one of them.

According to the USB standard, a device can have multiple audio functions,
each represented by Audio Interface Collection. Every audio function is
considered to be closed box and will contain unique AudioControl Interface
and zero or more AudioStreaming and MIDIStreaming Interfaces.

The Numark device adheres to the standard and defines two audio functions:
- MIDIStreaming function
- AudioStreaming function
It starts with MIDI function, followed by the audio function. The driver
saves the first AudioControl Interface in `snd_usb_audio` structure
associated with the entire device. It then attempts to use this interface
to query for terminals and clocks. However, this fails because the correct
information is stored in the second AudioControl Interface, defined in the
second Audio Interface Collection.

This patch introduces a structure holding association between each
MIDI/Audio Interface and its corresponding AudioControl Interface,
instead of relying on AudioControl Interface defined for the entire
device. This structure is populated during usb probing phase and leveraged
later when querying for terminals and when sending USB requests.

Alternative solutions considered include:
- defining a quirk for Numark where the order of interface is manually
changed, or terminals are hardcoded in the driver. This solution would
have fixed only this model, though it seems that device is USB compliant,
and it also seems that other devices from this company may be affected.
What's more, it looks like products from other manufacturers have similar
problems, i.e. Rane One DJ console
- keeping a list of all AudioControl Interfaces and querying all of them
to find required information. That would have solved my problem and have
low probability of breaking other devices, as we would always start with
the same logic of querying first AudioControl Interface. This solution
would not have followed the standard though.

This patch preserves the `snd_usb_audio.ctrl_intf` variable, which holds
the first AudioControl Interface, and uses it as a fallback when some
interfaces are not parsed correctly and lack an associated AudioControl
Interface, i.e., when configured via quirks.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=217865
Signed-off-by: Karol Kosik <k.kosik@outlook.com>
Link: https://patch.msgid.link/AS8P190MB1285893F4735C8B32AD3886BEC852@AS8P190MB1285.EURP190.PROD.OUTLOOK.COM
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2024-08-12 16:17:46 +02:00
Takashi Iwai
86a9bb5bf9 ALSA: usb-audio: Drop CONFIG_PM ifdefs
Practically seen, CONFIG_PM is almost mandatory.
Let's drop the ugly ifdef lines and simplify the code.

Link: https://lore.kernel.org/r/20211202084053.18201-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-12-06 10:19:40 +01:00
Jorge Sanjuan
11785ef532 ALSA: usb-audio: Initial Power Domain support
Thee USB Audio Class 3 (UAC3) introduces Power Domains as a new
feature to let a host turn individual parts of an audio function
to different power states via USB requests. This lets the device
get to know a bit amore about what the host is up to in order to
optimize power consumption efficiently.

The Power Domains are optional for UAC3 configuration but all
UAC3 devices shall include at least one BADD configuration where
the support for Power Domains is compulsory.

This patch adds a set of features/helpers to parse these power
domains and change their status.

Signed-off-by: Jorge Sanjuan <jorge.sanjuan@codethink.co.uk>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-07-31 15:01:22 +02:00
Greg Kroah-Hartman
b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00
Oliver Neukum
88a8516a21 ALSA: usbaudio: implement USB autosuspend
Devices are autosuspended if no pcm nor midi channel is open
Mixer devices may be opened. This way they are active when
in use to play or record sound, but can be suspended while
users have a mixer application running.

[Small clean-ups using static inline by tiwai]

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2011-03-11 14:59:29 +01:00