ffd63f2437
[ Upstream commit eaa1b01fe709d6a236a9cec74813e0400601fd23 ] For devices with multiple clock sources connected to a selector, we need to check what a clock selector control request has returned. This is needed to ensure that a requested clock source is indeed selected and for autoclock feature to work. For devices with single clock source connected, if we get an error there is nothing else we can do about it. We can't skip clock selector setup as it is required by some devices. So lets just ignore error in this case. This should fix various buggy Mackie devices: [ 649.109785] usb 1-1.3: parse_audio_format_rates_v2v3(): unable to find clock source (clock -32) [ 649.111946] usb 1-1.3: parse_audio_format_rates_v2v3(): unable to find clock source (clock -32) [ 649.113822] usb 1-1.3: parse_audio_format_rates_v2v3(): unable to find clock source (clock -32) There is also interesting info from the Windows documentation [1] (this is probably why manufacturers dont't even test this feature): "The USB Audio 2.0 driver doesn't support clock selection. The driver uses the Clock Source Entity, which is selected by default and never issues a Clock Selector Control SET CUR request." Link: https://learn.microsoft.com/en-us/windows-hardware/drivers/audio/usb-2-0-audio-drivers [1] Link: https://bugzilla.kernel.org/show_bug.cgi?id=217314 Link: https://bugzilla.kernel.org/show_bug.cgi?id=218175 Link: https://bugzilla.kernel.org/show_bug.cgi?id=218342 Signed-off-by: Alexander Tsoy <alexander@tsoy.me> Link: https://lore.kernel.org/r/20240201115308.17838-1-alexander@tsoy.me Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.