RE: [RFC] r8152: pass through needs to be singular

[Hayes Wang <hayeswang@realtek.com>]

Oliver Neukum <oneukum@suse.com>
> Sent: Friday, July 29, 2022 3:19 AM
[...]
> @@ -1608,6 +1622,12 @@ static int vendor_mac_passthru_addr_read(struct
> r8152 *tp, struct sockaddr *sa)
>  	acpi_object_type mac_obj_type;
>  	int mac_strlen;
> 
> +	mutex_lock(&pass_through_lock);
> +
> +	if (!holder_of_pass_through) {
> +		ret = -EBUSY;
> +		goto failout;
> +	}

Excuse me. I have one question.
When is the holder_of_pass_through set?
The default value of holder_of_pass_through is NULL, so
it seems the holder_of_pass_through would never be set.

Best Regards,
Hayes

>  	if (tp->lenovo_macpassthru) {
>  		mac_obj_name = "\\MACA";
>  		mac_obj_type = ACPI_TYPE_STRING;
> @@ -1621,7 +1641,8 @@ static int vendor_mac_passthru_addr_read(struct
> r8152 *tp, struct sockaddr *sa)
>  			if ((ocp_data & PASS_THRU_MASK) != 1) {
>  				netif_dbg(tp, probe, tp->netdev,
>  						"No efuse for RTL8153-AD MAC pass through\n");
> -				return -ENODEV;
> +				ret = -ENODEV;
> +				goto failout;
>  			}
>  		} else {
>  			/* test for RTL8153-BND and RTL8153-BD */
> @@ -1629,7 +1650,8 @@ static int vendor_mac_passthru_addr_read(struct
> r8152 *tp, struct sockaddr *sa)
>  			if ((ocp_data & BND_MASK) == 0 && (ocp_data & BD_MASK)
> == 0) {
>  				netif_dbg(tp, probe, tp->netdev,
>  						"Invalid variant for MAC pass through\n");
> -				return -ENODEV;
> +				ret = -ENODEV;
> +				goto failout;
>  			}
>  		}
> 
> @@ -1641,8 +1663,10 @@ static int vendor_mac_passthru_addr_read(struct
> r8152 *tp, struct sockaddr *sa)
>  	/* returns _AUXMAC_#AABBCCDDEEFF# */
>  	status = acpi_evaluate_object(NULL, mac_obj_name, NULL, &buffer);
>  	obj = (union acpi_object *)buffer.pointer;
> -	if (!ACPI_SUCCESS(status))
> -		return -ENODEV;
> +	if (!ACPI_SUCCESS(status)) {
> +		ret = -ENODEV;
> +		goto failout;
> +	}
>  	if (obj->type != mac_obj_type || obj->string.length != mac_strlen) {
>  		netif_warn(tp, probe, tp->netdev,
>  			   "Invalid buffer for pass-thru MAC addr: (%d, %d)\n",
> @@ -1670,6 +1694,10 @@ static int vendor_mac_passthru_addr_read(struct
> r8152 *tp, struct sockaddr *sa)
> 
>  amacout:
>  	kfree(obj);
> +failout:
> +	if (!ret)
> +		holder_of_pass_through = tp;
> +	mutex_unlock(&pass_through_lock);
>  	return ret;
>  }