staging: most: hdm-usb: remove filtering of networking state

In case the networking interface goes down and up again, the USB HDM does
not report the state the MOST networking interface controller is in. This
might lead to nonfunctional network.

Since the networking AIM already takes care of hardware address checking
and tracing it can be removed from the HDM USB, which is what this patch is
doing.

Signed-off-by: Andrey Shvetsov <andrey.shvetsov@k2l.de>
Signed-off-by: Christian Gromm <christian.gromm@microchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/most/hdm-usb/hdm_usb.c

@@ -97,9 +97,7 @@ struct clear_hold_work {
  * @cap: channel capabilities
  * @conf: channel configuration
  * @dci: direct communication interface of hardware
- * @hw_addr: MAC address of hardware
  * @ep_address: endpoint address table
- * @link_stat: link status of hardware
  * @description: device description
  * @suffix: suffix for channel name
  * @channel_lock: synchronize channel access
@@ -117,9 +115,7 @@ struct most_dev {
 	struct most_channel_capability *cap;
 	struct most_channel_config *conf;
 	struct most_dci_obj *dci;
-	u8 hw_addr[6];
 	u8 *ep_address;
-	u16 link_stat;
 	char description[MAX_STRING_LEN];
 	char suffix[MAX_NUM_ENDPOINTS][MAX_SUFFIX_LEN];
 	spinlock_t channel_lock[MAX_NUM_ENDPOINTS]; /* sync channel access */
@@ -737,56 +733,6 @@ exit:
 	return 0;
 }
 
-/**
- * hdm_update_netinfo - retrieve latest networking information
- * @mdev: device interface
- *
- * This triggers the USB vendor requests to read the hardware address and
- * the current link status of the attached device.
- */
-static int hdm_update_netinfo(struct most_dev *mdev)
-{
-	struct usb_device *usb_device = mdev->usb_device;
-	struct device *dev = &usb_device->dev;
-	u16 hi, mi, lo, link;
-
-	if (!is_valid_ether_addr(mdev->hw_addr)) {
-		if (drci_rd_reg(usb_device, DRCI_REG_HW_ADDR_HI, &hi) < 0) {
-			dev_err(dev, "Vendor request \"hw_addr_hi\" failed\n");
-			return -EFAULT;
-		}
-
-		if (drci_rd_reg(usb_device, DRCI_REG_HW_ADDR_MI, &mi) < 0) {
-			dev_err(dev, "Vendor request \"hw_addr_mid\" failed\n");
-			return -EFAULT;
-		}
-
-		if (drci_rd_reg(usb_device, DRCI_REG_HW_ADDR_LO, &lo) < 0) {
-			dev_err(dev, "Vendor request \"hw_addr_low\" failed\n");
-			return -EFAULT;
-		}
-
-		mutex_lock(&mdev->io_mutex);
-		mdev->hw_addr[0] = hi >> 8;
-		mdev->hw_addr[1] = hi;
-		mdev->hw_addr[2] = mi >> 8;
-		mdev->hw_addr[3] = mi;
-		mdev->hw_addr[4] = lo >> 8;
-		mdev->hw_addr[5] = lo;
-		mutex_unlock(&mdev->io_mutex);
-	}
-
-	if (drci_rd_reg(usb_device, DRCI_REG_NI_STATE, &link) < 0) {
-		dev_err(dev, "Vendor request \"link status\" failed\n");
-		return -EFAULT;
-	}
-
-	mutex_lock(&mdev->io_mutex);
-	mdev->link_stat = link;
-	mutex_unlock(&mdev->io_mutex);
-	return 0;
-}
-
 /**
  * hdm_request_netinfo - request network information
  * @iface: pointer to interface
@@ -807,7 +753,7 @@ static void hdm_request_netinfo(struct most_interface *iface, int channel)
 }
 
 /**
- * link_stat_timer_handler - add work to link_stat work queue
+ * link_stat_timer_handler - schedule work obtaining mac address and link status
  * @data: pointer to USB device instance
  *
  * The handler runs in interrupt context. That's why we need to defer the
@@ -823,33 +769,47 @@ static void link_stat_timer_handler(unsigned long data)
 }
 
 /**
- * wq_netinfo - work queue function
+ * wq_netinfo - work queue function to deliver latest networking information
  * @wq_obj: object that holds data for our deferred work to do
  *
  * This retrieves the network interface status of the USB INIC
- * and compares it with the current status. If the status has
- * changed, it updates the status of the core.
  */
 static void wq_netinfo(struct work_struct *wq_obj)
 {
 	struct most_dev *mdev = to_mdev_from_work(wq_obj);
-	int i, prev_link_stat = mdev->link_stat;
-	u8 prev_hw_addr[6];
+	struct usb_device *usb_device = mdev->usb_device;
+	struct device *dev = &usb_device->dev;
+	u16 hi, mi, lo, link;
+	u8 hw_addr[6];
 
-	for (i = 0; i < 6; i++)
-		prev_hw_addr[i] = mdev->hw_addr[i];
+	if (drci_rd_reg(usb_device, DRCI_REG_HW_ADDR_HI, &hi) < 0) {
+		dev_err(dev, "Vendor request 'hw_addr_hi' failed\n");
+		return;
+	}
 
-	if (hdm_update_netinfo(mdev) < 0)
+	if (drci_rd_reg(usb_device, DRCI_REG_HW_ADDR_MI, &mi) < 0) {
+		dev_err(dev, "Vendor request 'hw_addr_mid' failed\n");
 		return;
-	if (prev_link_stat != mdev->link_stat ||
-	    prev_hw_addr[0] != mdev->hw_addr[0] ||
-	    prev_hw_addr[1] != mdev->hw_addr[1] ||
-	    prev_hw_addr[2] != mdev->hw_addr[2] ||
-	    prev_hw_addr[3] != mdev->hw_addr[3] ||
-	    prev_hw_addr[4] != mdev->hw_addr[4] ||
-	    prev_hw_addr[5] != mdev->hw_addr[5])
-		most_deliver_netinfo(&mdev->iface, mdev->link_stat,
-				     &mdev->hw_addr[0]);
+	}
+
+	if (drci_rd_reg(usb_device, DRCI_REG_HW_ADDR_LO, &lo) < 0) {
+		dev_err(dev, "Vendor request 'hw_addr_low' failed\n");
+		return;
+	}
+
+	if (drci_rd_reg(usb_device, DRCI_REG_NI_STATE, &link) < 0) {
+		dev_err(dev, "Vendor request 'link status' failed\n");
+		return;
+	}
+
+	hw_addr[0] = hi >> 8;
+	hw_addr[1] = hi;
+	hw_addr[2] = mi >> 8;
+	hw_addr[3] = mi;
+	hw_addr[4] = lo >> 8;
+	hw_addr[5] = lo;
+
+	most_deliver_netinfo(&mdev->iface, link, hw_addr);
 }
 
 /**