973794e856
Intel stress-tests routinely report IO timeouts and invalid power
management transitions. Upon further analysis, we seem to be using the
wrong devices in pm_runtime calls.
Before reading and writing registers, we first need to make sure the
Slave is fully resumed. The existing code attempts to do such that,
however because of a confusion dating from 2017 and copy/paste, we
end-up resuming the parent only instead of resuming the codec device.
This can lead to accesses to the Slave registers while the bus is
still being configured and the Slave not enumerated, and as a result
IO errors occur.
This is a classic problem, similar confusions happened for HDaudio
between bus and codec device, leading to power management issues.
Fix by using the relevant device for all uses of pm_runtime functions.
Fixes: 60ee9be255712 ('soundwire: bus: add PM/no-PM versions of read/write functions')
Fixes: aa79293517b39 ('soundwire: bus: fix io error when processing alert event')
Fixes: 9d715fa005ebc ('soundwire: Add IO transfer')
Reported-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20210122070634.12825-9-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
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.