9ce650a75a
USB-audio driver behaves a bit strangely for the playback stream -- namely, it starts sending silent packets at PCM prepare state while the actual data is submitted at first when the trigger START is kicked off. This is a workaround for the behavior where URBs are processed too quickly at the beginning. That is, if we start submitting URBs at trigger START, the first few URBs will be immediately completed, and this would result in the immediate period-elapsed calls right after the start, which may confuse applications. OTOH, submitting the data after silent URBs would, of course, result in a certain delay of the actual data processing, and this is rather more serious problem on modern systems, in practice. This patch tries to revert the workaround and lets the URB submission starting at PCM trigger for the playback again. As far as I've tested with various backends (native ALSA, PA, JACK, PW), I haven't seen any problems (famous last words :) Note that the capture stream handling needs no such workaround, since the capture is driven per received URB. Link: https://lore.kernel.org/r/20210601162457.4877-6-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de> |
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| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
README
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.