net: cdc_ncm: Add ACPI MAC address pass through functionality

This change adds support to cdc_ncm for ACPI MAC address pass through functionality that also exists in the Realtek r8152 driver. This is in support of Dell's Universal Dock D6000, to give it the same feature capability as is currently available in Windows and advertized on Dell's product web site.

Signed-off-by Charles Hyde <[email protected]>

Cc Mario Limonciello <[email protected]>

Cc [email protected]

Cc Oliver Neukum <[email protected]>

Cc "Rafael J. Wysocki" <[email protected]>

Cc Len Brown <[email protected]>

Cc [email protected]

Cc [email protected]

---
 drivers/net/usb/cdc_ncm.c | 74 +++++++++++++++++++++++++++++++++------
 1 file changed, 64 insertions(+), 10 deletions(-)

drivers/net/usb/cdc_ncm.c +20 -0

index 85093579612f..e0152d44f5af 100644
@@ -52,6 +52,7 @@
 #include <linux/usb/usbnet.h>
 #include <linux/usb/cdc.h>
 #include <linux/usb/cdc_ncm.h>
+#include <acpi/acpi_mac_passthru.h>
 
 #if IS_ENABLED(CONFIG_USB_NET_CDC_MBIM)
 static bool prefer_mbim = true;

@@ -833,6 +834,45 @@ static const struct net_device_ops cdc_ncm_netdev_ops = {
 	.ndo_validate_addr   = eth_validate_addr,
 };
 
+static int get_ethernet_addr(struct usb_interface *intf)
+{
+	struct sockaddr sa;
+	struct usbnet *dev = usb_get_intfdata(intf);
+	struct cdc_ncm_ctx *ctx;
+	int ret = 0;
+
+	if (!dev)
+		return 0;
+
+	ctx = (struct cdc_ncm_ctx *)dev->data[0];
+	if (!ctx->ether_desc)
+		return 0;
+
+	ret = cdc_ncm_get_ethernet_address(dev, ctx);
+	if (ret) {
+		dev_dbg(&intf->dev, "failed to get mac address\n");
+		return ret;
+	}

drivers/net/usb/cdc_ncm.c +34 -10

+					memcpy(dev->net->dev_addr, sa.sa_data,
+					       ETH_ALEN);
+			}
+		}
+	}
+	dev_info(&intf->dev, "MAC-Address: %pM\n", dev->net->dev_addr);
+
+	return 0;
+}
+
 int cdc_ncm_bind_common(struct usbnet *dev, struct usb_interface *intf, u8 data_altsetting, int drvflags)
 {
 	struct cdc_ncm_ctx *ctx;

@@ -983,14 +1023,8 @@ int cdc_ncm_bind_common(struct usbnet *dev, struct usb_interface *intf, u8 data_
 	usb_set_intfdata(ctx->data, dev);
 	usb_set_intfdata(ctx->control, dev);
 
-	if (ctx->ether_desc) {
-		temp = usbnet_get_ethernet_addr(dev, ctx->ether_desc->iMACAddress);
-		if (temp) {
-			dev_dbg(&intf->dev, "failed to get mac address\n");
-			goto error2;
-		}
-		dev_info(&intf->dev, "MAC-Address: %pM\n", dev->net->dev_addr);
-	}
+	if (get_ethernet_addr(intf))
+		goto error2;
 
 	/* finish setting up the device specific data */
 	cdc_ncm_setup(dev);

@@ -1716,6 +1750,25 @@ static void cdc_ncm_status(struct usbnet *dev, struct urb *urb)
 	}
 }
 
+static int cdc_ncm_resume(struct usb_interface *intf)
+{
+	int ret;
+
+	ret = usbnet_resume(intf);
+	if (ret == 0)
+		get_ethernet_addr(intf);
+
+	return ret;
+}
+
+static int cdc_ncm_post_reset(struct usb_interface *intf)
+{
+	/* reset the MAC address in case of policy change */
+	get_ethernet_addr(intf);
+
+	return 0;
+}
+
 static const struct driver_info cdc_ncm_info = {
 	.description = "CDC NCM",
 	.flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET

@@ -1848,8 +1901,9 @@ static struct usb_driver cdc_ncm_driver = {
 	.probe = usbnet_probe,
 	.disconnect = usbnet_disconnect,
 	.suspend = usbnet_suspend,
-	.resume = usbnet_resume,
-	.reset_resume =	usbnet_resume,
+	.resume = cdc_ncm_resume,
+	.reset_resume =	cdc_ncm_resume,
+	.post_reset = cdc_ncm_post_reset,
 	.supports_autosuspend = 1,
 	.disable_hub_initiated_lpm = 1,
 };

Quoted 6 lines

+ if (strstr(dev->udev->product, "D6000")) {
+ sa.sa_family = dev->net->type;
+ if (get_acpi_mac_passthru(sa.sa_data)) {
+ if (!memcmp(dev->net->dev_addr, sa.sa_data,
+ ETH_ALEN)) {
+ if (!cdc_ncm_set_ethernet_address(dev, &sa))

How about use one if-statement instead of these three if-statement?

drivers/net/usb/cdc_ncm.c static const struct net_device_ops cdc_ncm_netdev_ops = { · line 860

Quoted 1 line · <[email protected]> writes:

drivers/net/usb/cdc_ncm.c +1 -0

+	if (strstr(dev->udev->product, "D6000")) {

Huh? Can you please test that on all USB devices ever made?