MCS7830 USB-Ether: resume _with_ working link, via .reset_resume support

ChangeLog:
Implement .reset_resume support to retain a live network connection
during suspend despite USB power loss.
- rework operation to reference cached data in mcs7830_data and
  netdev->dev_addr
- update netdev->dev_addr only in case new MAC was set successfully
. Tests done:
  . ethtool -d pre-/post-suspend: register values match
  . running ssh session suspend, resume: works
  . ifdown device, suspend, resume: works
  . ifup, suspend, unplug, resume: WORKS (eth1 is removed, re-ifup of eth1
    after card replug works)
  . verified identical MAC in ifconfig post-resume
    (ok, should be verified on network side to be fully certain...)

Keywords: suspend resume network connection dead interface down

Signed-off-by: Andreas Mohr <andi@lisas.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/usb/mcs7830.c b/drivers/net/usb/mcs7830.c
index 36a0292..6fc098f 100644 (file)
--- a/drivers/net/usb/mcs7830.c
+++ b/drivers/net/usb/mcs7830.c
@@ -12,8 +12,6 @@
  * Definitions gathered from MOSCHIP, Data Sheet_7830DA.pdf (thanks!).
  *
  * TODO:
- * - add .reset_resume support (iface is _gone_ after resume w/ power loss)
- * - verify that mcs7830_get_regs() does have same output pre-/post-suspend
  * - support HIF_REG_CONFIG_SLEEPMODE/HIF_REG_CONFIG_TXENABLE (via autopm?)
  * - implement ethtool_ops get_pauseparam/set_pauseparam
  *   via HIF_REG_PAUSE_THRESHOLD (>= revision C only!)
@@ -137,7 +135,7 @@ static int mcs7830_get_reg(struct usbnet *dev, u16 index, u16 size, void *data)
        return ret;
 }
 
-static int mcs7830_set_reg(struct usbnet *dev, u16 index, u16 size, void *data)
+static int mcs7830_set_reg(struct usbnet *dev, u16 index, u16 size, const void *data)
 {
        struct usb_device *xdev = dev->udev;
        int ret;
@@ -211,13 +209,43 @@ out:
        usb_free_urb(urb);
 }
 
-static int mcs7830_get_address(struct usbnet *dev)
+static int mcs7830_hif_get_mac_address(struct usbnet *dev, unsigned char *addr)
+{
+       int ret = mcs7830_get_reg(dev, HIF_REG_ETHERNET_ADDR, ETH_ALEN, addr);
+       if (ret < 0)
+               return ret;
+       return 0;
+}
+
+static int mcs7830_hif_set_mac_address(struct usbnet *dev, unsigned char *addr)
+{
+       int ret = mcs7830_set_reg(dev, HIF_REG_ETHERNET_ADDR, ETH_ALEN, addr);
+
+       if (ret < 0)
+               return ret;
+       return 0;
+}
+
+static int mcs7830_set_mac_address(struct net_device *netdev, void *p)
 {
        int ret;
-       ret = mcs7830_get_reg(dev, HIF_REG_ETHERNET_ADDR, ETH_ALEN,
-                                  dev->net->dev_addr);
+       struct usbnet *dev = netdev_priv(netdev);
+       struct sockaddr *addr = p;
+
+       if (netif_running(netdev))
+               return -EBUSY;
+
+       if (!is_valid_ether_addr(addr->sa_data))
+               return -EINVAL;
+
+       ret = mcs7830_hif_set_mac_address(dev, addr->sa_data);
+
        if (ret < 0)
                return ret;
+
+       /* it worked --> adopt it on netdev side */
+       memcpy(netdev->dev_addr, addr->sa_data, netdev->addr_len);
+
        return 0;
 }
 
@@ -359,33 +387,6 @@ static void mcs7830_rev_C_fixup(struct usbnet *dev)
        }
 }
 
-static int mcs7830_init_dev(struct usbnet *dev)
-{
-       int ret;
-       int retry;
-
-       /* Read MAC address from EEPROM */
-       ret = -EINVAL;
-       for (retry = 0; retry < 5 && ret; retry++)
-               ret = mcs7830_get_address(dev);
-       if (ret) {
-               dev_warn(&dev->udev->dev, "Cannot read MAC address\n");
-               goto out;
-       }
-
-       /* Set up PHY */
-       ret = mcs7830_set_autoneg(dev, 0);
-       if (ret) {
-               dev_info(&dev->udev->dev, "Cannot set autoneg\n");
-               goto out;
-       }
-
-       mcs7830_rev_C_fixup(dev);
-       ret = 0;
-out:
-       return ret;
-}
-
 static int mcs7830_mdio_read(struct net_device *netdev, int phy_id,
                             int location)
 {
@@ -406,11 +407,33 @@ static int mcs7830_ioctl(struct net_device *net, struct ifreq *rq, int cmd)
        return generic_mii_ioctl(&dev->mii, if_mii(rq), cmd, NULL);
 }
 
-/* credits go to asix_set_multicast */
-static void mcs7830_set_multicast(struct net_device *net)
+static inline struct mcs7830_data *mcs7830_get_data(struct usbnet *dev)
+{
+       return (struct mcs7830_data *)&dev->data;
+}
+
+static void mcs7830_hif_update_multicast_hash(struct usbnet *dev)
+{
+       struct mcs7830_data *data = mcs7830_get_data(dev);
+       mcs7830_set_reg_async(dev, HIF_REG_MULTICAST_HASH,
+                               sizeof data->multi_filter,
+                               data->multi_filter);
+}
+
+static void mcs7830_hif_update_config(struct usbnet *dev)
+{
+       /* implementation specific to data->config
+           (argument needs to be heap-based anyway - USB DMA!) */
+       struct mcs7830_data *data = mcs7830_get_data(dev);
+       mcs7830_set_reg_async(dev, HIF_REG_CONFIG, 1, &data->config);
+}
+
+static void mcs7830_data_set_multicast(struct net_device *net)
 {
        struct usbnet *dev = netdev_priv(net);
-       struct mcs7830_data *data = (struct mcs7830_data *)&dev->data;
+       struct mcs7830_data *data = mcs7830_get_data(dev);
+
+       memset(data->multi_filter, 0, sizeof data->multi_filter);
 
        data->config = HIF_REG_CONFIG_TXENABLE;
 
@@ -433,21 +456,51 @@ static void mcs7830_set_multicast(struct net_device *net)
                u32 crc_bits;
                int i;
 
-               memset(data->multi_filter, 0, sizeof data->multi_filter);
-
                /* Build the multicast hash filter. */
                for (i = 0; i < net->mc_count; i++) {
                        crc_bits = ether_crc(ETH_ALEN, mc_list->dmi_addr) >> 26;
                        data->multi_filter[crc_bits >> 3] |= 1 << (crc_bits & 7);
                        mc_list = mc_list->next;
                }
+       }
+}
 
-               mcs7830_set_reg_async(dev, HIF_REG_MULTICAST_HASH,
-                               sizeof data->multi_filter,
-                               data->multi_filter);
+static int mcs7830_apply_base_config(struct usbnet *dev)
+{
+       int ret;
+
+       /* re-configure known MAC (suspend case etc.) */
+       ret = mcs7830_hif_set_mac_address(dev, dev->net->dev_addr);
+       if (ret) {
+               dev_info(&dev->udev->dev, "Cannot set MAC address\n");
+               goto out;
        }
 
-       mcs7830_set_reg_async(dev, HIF_REG_CONFIG, 1, &data->config);
+       /* Set up PHY */
+       ret = mcs7830_set_autoneg(dev, 0);
+       if (ret) {
+               dev_info(&dev->udev->dev, "Cannot set autoneg\n");
+               goto out;
+       }
+
+       mcs7830_hif_update_multicast_hash(dev);
+       mcs7830_hif_update_config(dev);
+
+       mcs7830_rev_C_fixup(dev);
+       ret = 0;
+out:
+       return ret;
+}
+
+/* credits go to asix_set_multicast */
+static void mcs7830_set_multicast(struct net_device *net)
+{
+       struct usbnet *dev = netdev_priv(net);
+
+       mcs7830_data_set_multicast(net);
+
+       mcs7830_hif_update_multicast_hash(dev);
+       mcs7830_hif_update_config(dev);
 }
 
 static int mcs7830_get_regs_len(struct net_device *net)
@@ -491,29 +544,6 @@ static const struct ethtool_ops mcs7830_ethtool_ops = {
        .nway_reset             = usbnet_nway_reset,
 };
 
-static int mcs7830_set_mac_address(struct net_device *netdev, void *p)
-{
-       int ret;
-       struct usbnet *dev = netdev_priv(netdev);
-       struct sockaddr *addr = p;
-
-       if (netif_running(netdev))
-               return -EBUSY;
-
-       if (!is_valid_ether_addr(addr->sa_data))
-               return -EINVAL;
-
-       memcpy(netdev->dev_addr, addr->sa_data, netdev->addr_len);
-
-       ret = mcs7830_set_reg(dev, HIF_REG_ETHERNET_ADDR, ETH_ALEN,
-                       netdev->dev_addr);
-
-       if (ret < 0)
-               return ret;
-
-       return 0;
-}
-
 static const struct net_device_ops mcs7830_netdev_ops = {
        .ndo_open               = usbnet_open,
        .ndo_stop               = usbnet_stop,
@@ -530,14 +560,25 @@ static int mcs7830_bind(struct usbnet *dev, struct usb_interface *udev)
 {
        struct net_device *net = dev->net;
        int ret;
+       int retry;
 
-       ret = mcs7830_init_dev(dev);
+       /* Initial startup: Gather MAC address setting from EEPROM */
+       ret = -EINVAL;
+       for (retry = 0; retry < 5 && ret; retry++)
+               ret = mcs7830_hif_get_mac_address(dev, net->dev_addr);
+       if (ret) {
+               dev_warn(&dev->udev->dev, "Cannot read MAC address\n");
+               goto out;
+       }
+
+       mcs7830_data_set_multicast(net);
+
+       ret = mcs7830_apply_base_config(dev);
        if (ret)
                goto out;
 
        net->ethtool_ops = &mcs7830_ethtool_ops;
        net->netdev_ops = &mcs7830_netdev_ops;
-       mcs7830_set_multicast(net);
 
        /* reserve space for the status byte on rx */
        dev->rx_urb_size = ETH_FRAME_LEN + 1;
@@ -622,6 +663,20 @@ static const struct usb_device_id products[] = {
 };
 MODULE_DEVICE_TABLE(usb, products);
 
+static int mcs7830_reset_resume (struct usb_interface *intf)
+{
+       /* YES, this function is successful enough that ethtool -d
+           does show same output pre-/post-suspend */
+
+       struct usbnet           *dev = usb_get_intfdata(intf);
+
+       mcs7830_apply_base_config(dev);
+
+       usbnet_resume(intf);
+
+       return 0;
+}
+
 static struct usb_driver mcs7830_driver = {
        .name = driver_name,
        .id_table = products,
@@ -629,6 +684,7 @@ static struct usb_driver mcs7830_driver = {
        .disconnect = usbnet_disconnect,
        .suspend = usbnet_suspend,
        .resume = usbnet_resume,
+       .reset_resume = mcs7830_reset_resume,
 };
 
 static int __init mcs7830_init(void)