[PATCH v2 0/2] Support runtime changes of vendor mac passthu policy

[PATCH v2 0/2] Support runtime changes of vendor mac passthu policy

[Mario Limonciello]

On some platforms ACPI method `\\_SB.AMAC` is dynamic and changes to it can
influence changing the behavior of MAC pass through and what MAC address is used.

When running USB reset, re-read the MAC address to use to support tools that
change the policy.

This is quite similar to using `SIOCSIFHWADDR` except that the actual MAC to use
comes from ASL rather than from userspace.

Changes from v1:
 * Remove an extra unneeded `ether_addr_copy` call
 * Use `dev_set_mac_address` to ensure all notifiers are called
 * Shuffle functions to allow code re-use.

Mario Limonciello (2):
  r8152: remove extra action copying ethernet address
  r8152: Refresh MAC address during USBDEVFS_RESET

 drivers/net/usb/r8152.c | 51 +++++++++++++++++++++++++++++++++----------------
 1 file changed, 35 insertions(+), 16 deletions(-)

-- 
2.7.4

[PATCH v2 1/2] r8152: remove extra action copying ethernet address

[Mario Limonciello]

This already happens later on in `rtl8152_set_mac_address`

Signed-off-by: Mario Limonciello <mario.limonciello@dell.com>
---
 drivers/net/usb/r8152.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
index 86c8c64..dc1bfff 100644
--- a/drivers/net/usb/r8152.c
+++ b/drivers/net/usb/r8152.c
@@ -1212,7 +1212,6 @@ static int vendor_mac_passthru_addr_read(struct r8152 *tp, struct sockaddr *sa)
 		goto amacout;
 	}
 	memcpy(sa->sa_data, buf, 6);
-	ether_addr_copy(tp->netdev->dev_addr, sa->sa_data);
 	netif_info(tp, probe, tp->netdev,
 		   "Using pass-thru MAC addr %pM\n", sa->sa_data);
 
-- 
2.7.4

[PATCH v2 2/2] r8152: Refresh MAC address during USBDEVFS_RESET

[Mario Limonciello]

On some platforms it is possible to dynamically change the policy
of what MAC address is selected from the ASL at runtime.

These tools will reset the USB device and expect the change to be
made immediately.

Signed-off-by: Mario Limonciello <mario.limonciello@dell.com>
---
 drivers/net/usb/r8152.c | 50 ++++++++++++++++++++++++++++++++++---------------
 1 file changed, 35 insertions(+), 15 deletions(-)

diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
index dc1bfff..6d63dcb 100644
--- a/drivers/net/usb/r8152.c
+++ b/drivers/net/usb/r8152.c
@@ -1220,43 +1220,55 @@ static int vendor_mac_passthru_addr_read(struct r8152 *tp, struct sockaddr *sa)
 	return ret;
 }
 
-static int set_ethernet_addr(struct r8152 *tp)
+static int determine_ethernet_addr(struct r8152 *tp, struct sockaddr *sa)
 {
 	struct net_device *dev = tp->netdev;
-	struct sockaddr sa;
 	int ret;
 
 	if (tp->version == RTL_VER_01) {
-		ret = pla_ocp_read(tp, PLA_IDR, 8, sa.sa_data);
+		ret = pla_ocp_read(tp, PLA_IDR, 8, sa->sa_data);
 	} else {
 		/* if device doesn't support MAC pass through this will
 		 * be expected to be non-zero
 		 */
-		ret = vendor_mac_passthru_addr_read(tp, &sa);
+		ret = vendor_mac_passthru_addr_read(tp, sa);
 		if (ret < 0)
-			ret = pla_ocp_read(tp, PLA_BACKUP, 8, sa.sa_data);
+			ret = pla_ocp_read(tp, PLA_BACKUP, 8, sa->sa_data);
 	}
 
 	if (ret < 0) {
 		netif_err(tp, probe, dev, "Get ether addr fail\n");
-	} else if (!is_valid_ether_addr(sa.sa_data)) {
+	} else if (!is_valid_ether_addr(sa->sa_data)) {
 		netif_err(tp, probe, dev, "Invalid ether addr %pM\n",
-			  sa.sa_data);
+			  sa->sa_data);
 		eth_hw_addr_random(dev);
-		ether_addr_copy(sa.sa_data, dev->dev_addr);
-		ret = rtl8152_set_mac_address(dev, &sa);
+		ether_addr_copy(sa->sa_data, dev->dev_addr);
 		netif_info(tp, probe, dev, "Random ether addr %pM\n",
-			   sa.sa_data);
-	} else {
-		if (tp->version == RTL_VER_01)
-			ether_addr_copy(dev->dev_addr, sa.sa_data);
-		else
-			ret = rtl8152_set_mac_address(dev, &sa);
+			   sa->sa_data);
+		return 0;
 	}
 
 	return ret;
 }
 
+static int set_ethernet_addr(struct r8152 *tp)
+{
+	struct net_device *dev = tp->netdev;
+	struct sockaddr sa;
+	int ret;
+
+	ret = determine_ethernet_addr(tp, &sa);
+	if (ret < 0)
+		return ret;
+
+	if (tp->version == RTL_VER_01)
+		ether_addr_copy(dev->dev_addr, sa.sa_data);
+	else
+		ret = rtl8152_set_mac_address(dev, &sa);
+
+	return ret;
+}
+
 static void read_bulk_callback(struct urb *urb)
 {
 	struct net_device *netdev;
@@ -4263,10 +4275,18 @@ static int rtl8152_post_reset(struct usb_interface *intf)
 {
 	struct r8152 *tp = usb_get_intfdata(intf);
 	struct net_device *netdev;
+	struct sockaddr sa;
 
 	if (!tp)
 		return 0;
 
+	/* reset the MAC adddress in case of policy change */
+	if (determine_ethernet_addr(tp, &sa) >= 0) {
+		rtnl_lock();
+		dev_set_mac_address (tp->netdev, &sa, NULL);
+		rtnl_unlock();
+	}
+
 	netdev = tp->netdev;
 	if (!netif_running(netdev))
 		return 0;
-- 
2.7.4

Re: [PATCH v2 0/2] Support runtime changes of vendor mac passthu policy

[David Miller]

From: Mario Limonciello <mario.limonciello@dell.com>
Date: Thu,  4 Apr 2019 13:46:51 -0500

> On some platforms ACPI method `\\_SB.AMAC` is dynamic and changes to it can
> influence changing the behavior of MAC pass through and what MAC address is used.
> 
> When running USB reset, re-read the MAC address to use to support tools that
> change the policy.
> 
> This is quite similar to using `SIOCSIFHWADDR` except that the actual MAC to use
> comes from ASL rather than from userspace.
> 
> Changes from v1:
>  * Remove an extra unneeded `ether_addr_copy` call
>  * Use `dev_set_mac_address` to ensure all notifiers are called
>  * Shuffle functions to allow code re-use.

Series applied to net-next.