Re: [alsa-devel] [PATCH v4 07/15] soundwire: slave: move uevent handling to slave

From: Pierre-Louis Bossart
Date: Fri Dec 13 2019 - 17:16:20 EST

On 12/13/19 10:11 AM, Greg KH wrote:
On Fri, Dec 13, 2019 at 09:11:27AM -0600, Pierre-Louis Bossart wrote:
On 12/13/19 1:22 AM, Greg KH wrote:
On Thu, Dec 12, 2019 at 11:04:01PM -0600, Pierre-Louis Bossart wrote:
Currently the code deals with uevents at the bus level, but we only care
for Slave events

What does this mean? I can't understand it, can you please provide more
information on what you are doing here?

In the earlier versions of the patch, the code looks like this and there was
an open on what to do with a master-specific event.

static int sdw_uevent(struct device *dev, struct kobj_uevent_env *env)
+ struct sdw_master_device *md;
struct sdw_slave *slave;
char modalias[32];

- if (is_sdw_slave(dev)) {
+ if (is_sdw_md(dev)) {
+ md = to_sdw_master_device(dev);
+ /* TODO: do we need to call add_uevent_var() ? */
+ } else if (is_sdw_slave(dev)) {
slave = to_sdw_slave_device(dev);
+ sdw_slave_modalias(slave, modalias, sizeof(modalias));
+ if (add_uevent_var(env, "MODALIAS=%s", modalias))
+ return -ENOMEM;
} else {
dev_warn(dev, "uevent for unknown Soundwire type\n");
return -EINVAL;

Vinod suggested this was not needed and suggested the code for uevents be
moved to be slave-specific, which is what this patch does.

Then describe it really really well in the changelog text. We have no
rememberance of prior conversations when looking at commits in the tree
in the future.

ok, will do.