-----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(). 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.
+int sdw_master_device_add(struct sdw_bus *bus, struct device *parent,
struct fwnode_handle *fwnode)+{
- struct sdw_master_device *md;
- int ret;
- if (!bus)
return -EINVAL;- /*
* Unlike traditional devices, there's no allocation here since the* sdw_master_device is embedded in the bus structure.*/Looking at this and empty sdw_master_device_release() above, makes me wonder if it is a wise move? Should we rather allocate the sdw_master_device() and then free that up in sdw_master_device_release() or it is really overkill given that this is called when we remove the sdw_bus instance as well...
Yes, I will allocate sdw_master_device here and free it in sdw_master_device_release().
- md = &bus->md;
- md->dev.bus = &sdw_bus_type;
- md->dev.type = &sdw_master_type;
- md->dev.parent = parent;
- md->dev.of_node = parent->of_node;
- md->dev.fwnode = fwnode;
- md->dev.dma_mask = parent->dma_mask;
- dev_set_name(&md->dev, "sdw-master-%d", bus->link_id);
This give nice sdw-master-0. In DT this comes from reg property. I dont seem to recall if the ACPI/Disco spec treats link_id as unique across the system, can you check that please, if not we would need to update this.
Sure, I will check it.
-- ~Vinod