[PATCH linux v4 17/20] drivers/fsi: Set slave SMODE to init communications

[Jeremy Kerr]

Hi Chris,

> @@ -301,15 +376,26 @@ static int fsi_master_link_enable(struct fsi_master *master, int link)
>  static int fsi_master_break(struct fsi_master *master, int link)
>  {
>  	int rc;
> +	uint32_t smode;
>  
>  	if (!master->send_break)
>  		return -EINVAL;
>  
> -	rc =  master->send_break(master, link);
> -	if (rc)
> +	rc = master->send_break(master, link);
> +	if (rc) {
>  		dev_info(master->dev, "break failed with:%d\n", rc);
> +		return rc;
> +	}
> +	/* Verify can read slave at default ID location */
> +	rc = master->read(master, link, 3, FSI_SLAVE_BASE + FSI_SMODE,
> +			&smode, sizeof(smode));
>  
> -	return rc;
> +	/* If read fails then nothing on other end of link */
> +	if (rc)
> +		return -ENODEV;
> +
> +	dev_dbg(master->dev, "smode at ID 3 after break:%08x\n", smode);
> +	return 0;
>  }

Should this smode read logic be in fsi_master_break() at all?

I'd be inclined to keep the slave detection separate. If it's necessary
to check for slave presence, we can do that in the caller.

Cheers,


Jeremy