Re: [RFC PATCH] Soundwire: Initialize multi_link with fwnode props

[Greg KH]

On Sun, Aug 14, 2022 at 02:04:15PM +0600, Khalid Masum wrote:
> According to the TODO, In sw_bus_master_add, bus->multi_link is to be
> populated with properties from FW node props. Make this happen by 
> creating a new fwnode_handle flag FWNODE_FLAG_MULTI_LINKED and use 
> the flag to store the multi_link value from intel_link_startup. Use 
> this flag to initialize bus->multi_link.
> 
> Signed-off-by: Khalid Masum <khalid.masum.92@xxxxxxxxx>
> ---
> I do not think adding a new flag for fwnode_handle is a good idea.
> So, what would be the best way to initialize bus->multilink with 
> fwnode props?
> 
>   -- Khalid Masum
> 
>  drivers/soundwire/bus.c   | 4 ++--
>  drivers/soundwire/intel.c | 1 +
>  include/linux/fwnode.h    | 1 +
>  3 files changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c
> index a2bfb0434a67..80df1672c60b 100644
> --- a/drivers/soundwire/bus.c
> +++ b/drivers/soundwire/bus.c
> @@ -74,9 +74,9 @@ int sdw_bus_master_add(struct sdw_bus *bus, struct device *parent,
>  
>  	/*
>  	 * Initialize multi_link flag
> -	 * TODO: populate this flag by reading property from FW node
>  	 */
> -	bus->multi_link = false;
> +	bus->multi_link = (fwnode->flags & FWNODE_FLAG_MULTI_LINKED)
> +		== FWNODE_FLAG_MULTI_LINKED;
>  	if (bus->ops->read_prop) {
>  		ret = bus->ops->read_prop(bus);
>  		if (ret < 0) {
> diff --git a/drivers/soundwire/intel.c b/drivers/soundwire/intel.c
> index 505c5ef061e3..034d1c523ddf 100644
> --- a/drivers/soundwire/intel.c
> +++ b/drivers/soundwire/intel.c
> @@ -1347,6 +1347,7 @@ int intel_link_startup(struct auxiliary_device *auxdev)
>  		 */
>  		bus->multi_link = true;
>  		bus->hw_sync_min_links = 1;
> +		dev->fwnode->flags |= FWNODE_FLAG_MULTI_LINKED;
>  	}
>  
>  	/* Initialize shim, controller */
> diff --git a/include/linux/fwnode.h b/include/linux/fwnode.h
> index 9a81c4410b9f..446a52744953 100644
> --- a/include/linux/fwnode.h
> +++ b/include/linux/fwnode.h
> @@ -32,6 +32,7 @@ struct device;
>  #define FWNODE_FLAG_NOT_DEVICE			BIT(1)
>  #define FWNODE_FLAG_INITIALIZED			BIT(2)
>  #define FWNODE_FLAG_NEEDS_CHILD_BOUND_ON_ADD	BIT(3)
> +#define FWNODE_FLAG_MULTI_LINKED		BIT(4)

What does this commit actually change?

Did you test this on real hardware?

thanks,

greg k-h