The 'master' device acts as a glue layer used during bus
initialization only, and it needs to be 'transparent' for pm_runtime
management. Its behavior should be that it becomes active when one of
its children becomes active, and suspends when all of its children are
suspended.
In our tests on Intel platforms, we routinely see these sort of
warnings on the initial boot:
[ 21.447345] rt715 sdw:3:25d:715:0: runtime PM trying to activate
child device sdw:3:25d:715:0 but parent (sdw-master-3) is not active
This is root-caused to a missing setup to make the device 'active' on
probe. Since we don't want the device to remain active forever after
the probe, the autosuspend configuration is also enabled at the end of
the probe - the device will actually autosuspend only in the case
where there are no devices physically attached. In practice, the
master device will suspend when all its children are no longer active.
Fixes: bd84256e86 ('soundwire: master: enable pm runtime')
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/20201124130742.10986-1-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
The hierarchy of soundwire devices is platform device -> M device -> S
device. A S device is physically attached on the platform device. So the
platform device should be resumed when a S device is resumed. As the
bridge of platform device and S device, we have to implement runtime pm
on M driver. We have set runtime pm ops in M driver already, but still
need to enable runtime pm.
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200726215945.3119-1-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Add the master properties as attributes. The description is directly
derived from the MIPI DisCo specification.
Credits: this patch is based on an earlier internal contribution by
Vinod Koul, Sanyog Kale, Shreyas Nc and Hardik Shah.
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/20200518203551.2053-3-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
We need to enable runtime_pm on master device with generic helpers,
so that a Slave-initiated wake is propagated to the bus parent.
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Acked-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20200518174322.31561-6-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
In the existing SoundWire code, Master Devices are not explicitly
represented - only SoundWire Slave Devices are exposed (the use of
capital letters follows the SoundWire specification conventions).
With the existing code, the bus is handled without using a proper device,
and bus->dev typically points to a platform device. The right thing to
do as discussed in multiple reviews is use a device for each bus.
The sdw_master_device addition is done with minimal internal plumbing
and not exposed externally. The existing API based on
sdw_bus_master_add() and sdw_bus_master_delete() will deal with the
sdw_master_device life cycle, which minimizes changes to existing
drivers.
Note that the Intel code will be modified in follow-up patches (no
impact on any platform since the connection with ASoC is not supported
upstream so far).
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Acked-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20200518174322.31561-5-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Pierre-Louis Bossart
Bard Liao