On 11-05-20, 11:34, Liao, Bard wrote:
-----Original Message----- From: Vinod Koul vkoul@kernel.org Sent: Monday, May 11, 2020 5:00 PM To: Liao, Bard bard.liao@intel.com Cc: Bard Liao yung-chuan.liao@linux.intel.com; alsa-devel@alsa-project.org; linux-kernel@vger.kernel.org; tiwai@suse.de; broonie@kernel.org; gregkh@linuxfoundation.org; jank@cadence.com; srinivas.kandagatla@linaro.org; rander.wang@linux.intel.com; ranjani.sridharan@linux.intel.com; hui.wang@canonical.com; pierre- louis.bossart@linux.intel.com; Kale, Sanyog R sanyog.r.kale@intel.com; Blauciak, Slawomir slawomir.blauciak@intel.com; Lin, Mengdong mengdong.lin@intel.com Subject: Re: [PATCH 3/3] soundwire: bus_type: add sdw_master_device support
On 11-05-20, 08:04, Liao, Bard wrote:
-----Original Message----- From: Vinod Koul vkoul@kernel.org Sent: Monday, May 11, 2020 2:32 PM To: Bard Liao yung-chuan.liao@linux.intel.com Cc: alsa-devel@alsa-project.org; linux-kernel@vger.kernel.org; tiwai@suse.de; broonie@kernel.org; gregkh@linuxfoundation.org; jank@cadence.com; srinivas.kandagatla@linaro.org; rander.wang@linux.intel.com; ranjani.sridharan@linux.intel.com; hui.wang@canonical.com; pierre- louis.bossart@linux.intel.com; Kale, Sanyog R sanyog.r.kale@intel.com; Blauciak, Slawomir slawomir.blauciak@intel.com; Lin, Mengdong mengdong.lin@intel.com; Liao, Bard bard.liao@intel.com Subject: Re: [PATCH 3/3] soundwire: bus_type: add sdw_master_device support
On 30-04-20, 02:51, Bard Liao wrote:
@@ -24,9 +24,14 @@ int sdw_bus_master_add(struct sdw_bus *bus, struct
device *parent,
struct sdw_master_prop *prop = NULL; int ret;
- if (!bus->dev) {
pr_err("SoundWire bus has no device\n");return -ENODEV;This check is removed and not moved into sdw_master_device_add() either, can you add here or in patch 1 and keep checking the parent device please
We will set bus->dev = &md->dev in the end of sdw_master_device_add().
We need to test if this is valid or not :)
That's why we remove the test. But now I am wandering does it make sense to set bus->dev = &md->dev? Maybe it makes more sense to set bus->dev = sdw control device. A follow up question is that should slave device a child of bus device or master device? I would prefer bus device if it makes sense. I will check bus->dev and parent and remove bus->dev = &md->dev in the next version.
the parent is bus->dev and sdw_master_device created would be child of this and should be set as such. You can remove it from bus object and keep in sdw_master_device object, that is fine by me.
Looks like we don't need the parent and fwnode parameter since we can get them from bus->dev 😊
Quite right
The sdw_slave is child of sdw_master_device now and looks to be set correct.
So, it will be bus device -> master device -> slave device right?
yes
I have a question here. We have pm supported on bus and slave devices, but not master device. Will pm work with this architecture? Can it be bus device -> master device & slave device?
yes it would and you should check it out. The pm (runtime_pm) works well with child devices and parents, so we need to ensure that parents are set properly.
Thanks