Re: [PATCH] soundwire: debugfs: use controller id instead of link_id

[Srinivas Kandagatla]

On 21/01/2021 15:12, Pierre-Louis Bossart wrote:
> On 1/21/21 6:03 AM, Srinivas Kandagatla wrote:
> > On 19/01/2021 19:09, Pierre-Louis Bossart wrote:
> > > > currently we have
> > > > /sys/kernel/debug/soundwire/master-*
> > > >
> > > > Are you suggesting that we have something like this:
> > > >
> > > > /sys/kernel/debug/soundwire/xyz-controller/master-<LINK-ID> ??
> > >
> > > Yes this is what I was thinking about.
> >
> > Vinod/Pierre,
> >
> > One Question here,
> >
> > Why is link_id part of "struct sdw_bus", should it not be part of 
> > "struct sdw_master_device " ?
> >
> > Given that "There is one Link per each Master"
>
> it's true that link == master == bus at the concept level.
>
> but we have an existing code base with different structures and we can't 
> break too many things at once.
>
> In the existing flow, the 'bus' is created and setup first, the 
> sdw_bus_master_add() routine takes a 'bus' argument, and the link_id is 
> already set. This routine only creates a device and in the rest of the 
> code we keep using the 'bus' pointer, so there's no real short-term 
> scope for moving the information into the 'sdw_master_device' structure 
> - that would be a lot of surgery when nothing is really broken.

I totally agree!

If I understand it correctly in Intel case there will be only one Link 
ID per bus.


Does this change look good to you?

---------------->cut<---------------

diff --git a/drivers/soundwire/debugfs.c b/drivers/soundwire/debugfs.c
index b6cad0d59b7b..f22868614f09 100644
--- a/drivers/soundwire/debugfs.c
+++ b/drivers/soundwire/debugfs.c
@@ -19,13 +19,14 @@ void sdw_bus_debugfs_init(struct sdw_bus *bus)
                return;

        /* create the debugfs master-N */
+       bus->controller_debugfs = debugfs_create_dir(dev_name(bus->dev), 
sdw_debugfs_root);
        snprintf(name, sizeof(name), "master-%d", bus->link_id);
-       bus->debugfs = debugfs_create_dir(name, sdw_debugfs_root);
+       bus->debugfs = debugfs_create_dir(name, bus->controller_debugfs);
 }

 void sdw_bus_debugfs_exit(struct sdw_bus *bus)
 {
-       debugfs_remove_recursive(bus->debugfs);
+       debugfs_remove_recursive(bus->controller_debugfs);
 }

 #define RD_BUF (3 * PAGE_SIZE)
diff --git a/include/linux/soundwire/sdw.h b/include/linux/soundwire/sdw.h
index b198f471bea8..242bde30d8bd 100644
--- a/include/linux/soundwire/sdw.h
+++ b/include/linux/soundwire/sdw.h
@@ -877,6 +877,7 @@ struct sdw_bus {
        struct sdw_master_prop prop;
        struct list_head m_rt_list;
 #ifdef CONFIG_DEBUG_FS
+       struct dentry *controller_debugfs;
        struct dentry *debugfs;
 #endif
        struct sdw_defer defer_msg;

---------------->cut<---------------

With this change I get something like this on my board:

~# find /sys/kernel/debug/soundwire/
/sys/kernel/debug/soundwire/
/sys/kernel/debug/soundwire/sdw-master-2
/sys/kernel/debug/soundwire/sdw-master-2/master-0
/sys/kernel/debug/soundwire/sdw-master-2/master-0/sdw:0:217:2110:0:4
/sys/kernel/debug/soundwire/sdw-master-2/master-0/sdw:0:217:2110:0:4/registers
/sys/kernel/debug/soundwire/sdw-master-2/master-0/sdw:0:217:2110:0:3
/sys/kernel/debug/soundwire/sdw-master-2/master-0/sdw:0:217:2110:0:3/registers
/sys/kernel/debug/soundwire/sdw-master-1
/sys/kernel/debug/soundwire/sdw-master-1/master-0
/sys/kernel/debug/soundwire/sdw-master-1/master-0/sdw:0:217:10d:0:3
/sys/kernel/debug/soundwire/sdw-master-1/master-0/sdw:0:217:10d:0:3/registers
/sys/kernel/debug/soundwire/sdw-master-0
/sys/kernel/debug/soundwire/sdw-master-0/master-0
/sys/kernel/debug/soundwire/sdw-master-0/master-0/sdw:0:217:10d:0:4
/sys/kernel/debug/soundwire/sdw-master-0/master-0/sdw:0:217:10d:0:4/registers



Thanks,
srini