mirror of https://gitee.com/openkylin/linux.git
4a17c441c7
Somehow the existing code is not aligned with the steps described in the documentation, refactor code and make sure the register programming sequences are correct. Also add missing power-up, power-down and wake capabilities (the last two are used in follow-up patches but introduced here for consistency). Some of the SHIM registers exposed fields that are link specific, and in addition some of the power-related registers (SPA/CPA) take time to be updated. Uncontrolled access leads to timeouts or errors. Add a mutex, shared by all links, so that all accesses to such registers are serialized, and follow a pattern of read-modify-write. This includes making sure SHIM_SYNC is programmed only once, before the first master is powered on. We use a 'shim_mask' field, shared between all links and protected by a mutex, to deal with power-up and power-down sequences. Note that the SYNCPRD value is tied only to the XTAL value and not the current bus frequency or the frame rate. BugLink: https://github.com/thesofproject/linux/issues/1555 Signed-off-by: Rander Wang <rander.wang@intel.com> Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com> Link: https://lore.kernel.org/r/20200716150947.22119-3-yung-chuan.liao@linux.intel.com Signed-off-by: Vinod Koul <vkoul@kernel.org> |
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| LICENSES | ||
| arch | ||
| block | ||
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| 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 | ||
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| Kbuild | ||
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| 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.