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![]() This patch improves the delay calculation by relying on the LLP (Linear Link Position) on the DAI side and the LDP (Linear Data Pointer) on the host side. The LDP provides the same DMA position as LPIB, but with a linear count instead of a position in the ALSA ring buffer. The LDP values are provided in bytes and must be converted to frames. The difference in units means that the host counter will wrap earlier than the LLP. We need to wrap the LLP at the same boundary as the host counter. The ASoC framework relies on separate pointer and delay callback. Measurement errors can be reduced by processing all the counter values in the pointer callback. The delay value is stored, and will be reported to higher levels in the delay callback. For playback, the firmware provides a stream_start offset to handle mixing/pause usages, where the DAI might have started earlier than the PCM device. The delay calculation must be special-cased when the link counter has not reached the start offset value, i.e. no valid audio has left the DSP. Cc: stable@vger.kernel.org # 6.8 Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com> Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com> Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Link: https://msgid.link/r/20240321130814.4412-16-peter.ujfalusi@linux.intel.com Signed-off-by: Mark Brown <broonie@kernel.org> |
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arch | ||
block | ||
certs | ||
crypto | ||
Documentation | ||
drivers | ||
fs | ||
include | ||
init | ||
io_uring | ||
ipc | ||
kernel | ||
lib | ||
LICENSES | ||
mm | ||
net | ||
rust | ||
samples | ||
scripts | ||
security | ||
sound | ||
tools | ||
usr | ||
virt | ||
.clang-format | ||
.cocciconfig | ||
.editorconfig | ||
.get_maintainer.ignore | ||
.gitattributes | ||
.gitignore | ||
.mailmap | ||
.rustfmt.toml | ||
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 reStructuredText 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.