Linux mainline fork with MSM8998 patches | https://mainline.space | Currently supported devices:
OnePlus 5/5T, Xiaomi Mi 6, F(x)tec Pro¹ (2019 QX1000 model) & Sony Xperia XZ Premium (UNTESTED!)
9983ac49b7
Current SOF implementation limits period and buffer sizes to multiples of period_min. Period_min is defined in topology, but is in practise set to align with the SOF DSP timer tick (typically 1ms). While this approach helps user-space to avoid period sizes, which are not aligned to the DSP timer tick, it causes problems to applications which want to align data processing size to that of ALSA period size. One example is JACK audio server, which limits period sizes to power of two values. Other ALSA drivers where audio data transfer is driven by a timer tick, like USB, do not constraint period and buffer sizes to exact multiple of the timer tick. To align SOF to follow the same behaviour, drop the additional alignment constraints. As a side-effect, this patch can cause irregularity to period wakeup timing. This happens when application chooses settings which were previously forbidden. For example, if application configures period size to 2^14 bytes and audio config of S32_LE/2ch/48000Hz, one period represents 42.667ms of audio. Without this patch, this configuration is not allowed by SOF. With the patch applied, configuration is allowed but the wakeups are paced by the DSP timer tick, which is typically 1ms. Application will see period wakeups with a 42/43/42/43ms repeating pattern. Both approaches are valid within ALSA context, but relaxing the constraints is better aligned with existing applications and other ALSA drivers like USB audio. Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com> Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com> Link: https://lore.kernel.org/r/20201118140545.2138895-1-kai.vehmanen@linux.intel.com Signed-off-by: Mark Brown <broonie@kernel.org> |
||
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| 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 | ||
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.