a4bb75c4f1
Introduce SNDRV_PCM_INFO_PERFECT_DRAIN and SNDRV_PCM_HW_PARAMS_NO_DRAIN_SILENCE flags to fully control the filling of the silence samples in the drain ioctl. Actually, the configurable silencing is going to be implemented in the user space [1], but drivers (hardware) may not require this operation. Those flags do the bidirectional setup for this operation: 1) driver may notify the presence of the perfect drain 2) user space may not require the filling of the silence samples to inhibit clicks If we decide to move this operation to the kernel space in future, the SNDRV_PCM_INFO_PERFECT_DRAIN flag may handle this situation without double "silence" processing (user + kernel space). The ALSA API should be universal, so forcing the behaviour (modifying of the ring buffer with any samples) for the drain operation is not ideal. [1] https://lore.kernel.org/alsa-devel/20230502115010.986325-1-perex@perex.cz/ [ fixed a typo in comment by tiwai ] Signed-off-by: Jaroslav Kysela <perex@perex.cz> Link: https://lore.kernel.org/r/20230502115536.986900-1-perex@perex.cz Signed-off-by: Takashi Iwai <tiwai@suse.de>
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.