Re: [PATCH] soundwire: fix initializing sysfs for same devices on different buses

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Wed, Oct 04, 2023 at 03:02:43PM +0200, Krzysztof Kozlowski wrote:
> If same devices with same device IDs are present on different soundwire
> buses, the probe fails due to conflicting device names and sysfs
> entries:
> 
>   sysfs: cannot create duplicate filename '/bus/soundwire/devices/sdw:0:0217:0204:00:0'
> 
> The link ID is 0 for both devices, so they should be differentiated by
> bus ID.  Add the bus ID so, the device names and sysfs entries look
> like:
> 
>   sdw:1:0:0217:0204:00:0 -> ../../../devices/platform/soc@0/6ab0000.soundwire-controller/sdw-master-1/sdw:1:0:0217:0204:00:0
>   sdw:3:0:0217:0204:00:0 -> ../../../devices/platform/soc@0/6b10000.soundwire-controller/sdw-master-3/sdw:3:0:0217:0204:00:0
> 
> Fixes: 7c3cd189b86d ("soundwire: Add Master registration")
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> 
> ---
> 
> Sending as RFT, because I did not test it on that many devices and
> user-spaces.
> ---
>  drivers/soundwire/slave.c | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/soundwire/slave.c b/drivers/soundwire/slave.c
> index c1c1a2ac293a..4db43ea53d47 100644
> --- a/drivers/soundwire/slave.c
> +++ b/drivers/soundwire/slave.c
> @@ -39,14 +39,14 @@ int sdw_slave_add(struct sdw_bus *bus,
>  	slave->dev.fwnode = fwnode;
>  
>  	if (id->unique_id == SDW_IGNORED_UNIQUE_ID) {
> -		/* name shall be sdw:link:mfg:part:class */
> -		dev_set_name(&slave->dev, "sdw:%01x:%04x:%04x:%02x",
> -			     bus->link_id, id->mfg_id, id->part_id,
> +		/* name shall be sdw:bus:link:mfg:part:class */
> +		dev_set_name(&slave->dev, "sdw:%01x:%01x:%04x:%04x:%02x",
> +			     bus->id, bus->link_id, id->mfg_id, id->part_id,
>  			     id->class_id);
>  	} else {
> -		/* name shall be sdw:link:mfg:part:class:unique */
> -		dev_set_name(&slave->dev, "sdw:%01x:%04x:%04x:%02x:%01x",
> -			     bus->link_id, id->mfg_id, id->part_id,
> +		/* name shall be sdw:bus:link:mfg:part:class:unique */
> +		dev_set_name(&slave->dev, "sdw:%01x:%01x:%04x:%04x:%02x:%01x",
> +			     bus->id, bus->link_id, id->mfg_id, id->part_id,

Shouldn't some documenation also be changed somewhere that describes the
device id?

thanks,

greg k-h