6f206833ce
The existing debug log only mentions a state change, without providing any details. For integration and stress-tests, it's helpful to see in the dmesg log the reason for the state change. The value is intended for power users and isn't converted as human-readable values. But for the record each device has a 4-bit status: BIT(0): Unattached BIT(1): Attached BIT(2): Alert BIT(3): Reserved (should not happen) Example: [ 121.891288] intel-sdw intel-sdw.0: Slave status change: 0x2 << this shows a Device0 Attached [ 121.891295] soundwire sdw-master-0: Slave attached, programming device number [ 121.891629] soundwire sdw-master-0: SDW Slave Addr: 30025d071101 [ 121.891632] soundwire sdw-master-0: SDW Slave class_id 1, part_id 711, mfg_id 25d, unique_id 0, version 3 [ 121.892011] intel-sdw intel-sdw.0: Msg ignored for Slave 0 [ 121.892013] soundwire sdw-master-0: No more devices to enumerate [ 121.892200] intel-sdw intel-sdw.0: Slave status change: 0x21 << this shows the device now Attached as Device1 and Unattached as Device0, i.e. a successful enumeration. 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/20210115053738.22630-3-yung-chuan.liao@linux.intel.com Signed-off-by: Vinod Koul <vkoul@kernel.org> |
||
|---|---|---|
| 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.