p54usb: utilize usb_reset_device for 3887

Sometimes on unload or reboot the 3887 USB devices become stuck.
<usual log entry>
kernel: usbcore: registered new interface driver p54usb
kernel: usb 2-10: (p54usb) reset failed! (-110)
kernel: p54usb: probe of 2-10:1.0 failed with error -110
[...]

and a physical unplug and replug was necessary.
However we should be able to do this in software as well,
without any user interaction.

Signed-off-by: Christian Lamparter <chunkeey@web.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

2 files changed, 58 insertions, 13 deletions

diff --git a/drivers/net/wireless/p54/p54usb.c b/drivers/net/wireless/p54/p54usb.c
index 5de2ebfb28c7..3c31c15267b5 100644
--- a/drivers/net/wireless/p54/p54usb.c
+++ b/drivers/net/wireless/p54/p54usb.c
@@ -424,9 +424,44 @@ static int p54u_bulk_msg(struct p54u_priv *priv, unsigned int ep,
                             data, len, &alen, 2000);
 }
 
+static const char p54u_romboot_3887[] = "~~~~";
+static const char p54u_firmware_upload_3887[] = "<\r";
+
+static int p54u_device_reset_3887(struct ieee80211_hw *dev)
+{
+        struct p54u_priv *priv = dev->priv;
+        int ret, lock;
+        u8 buf[4];
+
+        ret = lock = usb_lock_device_for_reset(priv->udev, priv->intf);
+        if (ret < 0) {
+                dev_err(&priv->udev->dev, "(p54usb) unable to lock device for "
+                        "reset: %d\n", ret);
+                return ret;
+        }
+
+        ret = usb_reset_device(priv->udev);
+        if (lock)
+                usb_unlock_device(priv->udev);
+
+        if (ret) {
+                dev_err(&priv->udev->dev, "(p54usb) unable to reset "
+                        "device: %d\n", ret);
+                return ret;
+        }
+
+        memcpy(&buf, p54u_romboot_3887, sizeof(buf));
+        ret = p54u_bulk_msg(priv, P54U_PIPE_DATA,
+                            buf, sizeof(buf));
+        if (ret)
+                dev_err(&priv->udev->dev, "(p54usb) unable to jump to "
+                        "boot ROM: %d\n", ret);
+
+        return ret;
+}
+
 static int p54u_upload_firmware_3887(struct ieee80211_hw *dev)
 {
-        static char start_string[] = "~~~~<\r";
         struct p54u_priv *priv = dev->priv;
         const struct firmware *fw_entry = NULL;
         int err, alen;
@@ -445,12 +480,9 @@ static int p54u_upload_firmware_3887(struct ieee80211_hw *dev)
                 goto err_bufalloc;
         }
 
-        memcpy(buf, start_string, 4);
-        err = p54u_bulk_msg(priv, P54U_PIPE_DATA, buf, 4);
-        if (err) {
-                dev_err(&priv->udev->dev, "(p54usb) reset failed! (%d)\n", err);
+        err = p54u_device_reset_3887(dev);
+        if (err)
                 goto err_reset;
-        }
 
         err = request_firmware(&fw_entry, "isl3887usb", &priv->udev->dev);
         if (err) {
@@ -467,14 +499,14 @@ static int p54u_upload_firmware_3887(struct ieee80211_hw *dev)
                 goto err_upload_failed;
 
         left = block_size = min((size_t)P54U_FW_BLOCK, fw_entry->size);
-        strcpy(buf, start_string);
-        left -= strlen(start_string);
-        tmp += strlen(start_string);
+        strcpy(buf, p54u_firmware_upload_3887);
+        left -= strlen(p54u_firmware_upload_3887);
+        tmp += strlen(p54u_firmware_upload_3887);
 
         data = fw_entry->data;
         remains = fw_entry->size;
 
-        hdr = (struct x2_header *)(buf + strlen(start_string));
+        hdr = (struct x2_header *)(buf + strlen(p54u_firmware_upload_3887));
         memcpy(hdr->signature, X2_SIGNATURE, X2_SIGNATURE_SIZE);
         hdr->fw_load_addr = cpu_to_le32(ISL38XX_DEV_FIRMWARE_ADDR);
         hdr->fw_length = cpu_to_le32(fw_entry->size);
@@ -876,6 +908,9 @@ static int __devinit p54u_probe(struct usb_interface *intf,
         SET_IEEE80211_DEV(dev, &intf->dev);
         usb_set_intfdata(intf, dev);
         priv->udev = udev;
+        priv->intf = intf;
+        skb_queue_head_init(&priv->rx_queue);
+        init_usb_anchor(&priv->submitted);
 
         usb_get_dev(udev);
 
@@ -918,9 +953,6 @@ static int __devinit p54u_probe(struct usb_interface *intf,
         if (err)
                 goto err_free_dev;
 
-        skb_queue_head_init(&priv->rx_queue);
-        init_usb_anchor(&priv->submitted);
-
         p54u_open(dev);
         err = p54_read_eeprom(dev);
         p54u_stop(dev);
@@ -958,11 +990,23 @@ static void __devexit p54u_disconnect(struct usb_interface *intf)
         ieee80211_free_hw(dev);
 }
 
+static int p54u_pre_reset(struct usb_interface *intf)
+{
+        return 0;
+}
+
+static int p54u_post_reset(struct usb_interface *intf)
+{
+        return 0;
+}
+
 static struct usb_driver p54u_driver = {
         .name   = "p54usb",
         .id_table = p54u_table,
         .probe = p54u_probe,
         .disconnect = p54u_disconnect,
+        .pre_reset = p54u_pre_reset,
+        .post_reset = p54u_post_reset,
 };
 
 static int __init p54u_init(void)
diff --git a/drivers/net/wireless/p54/p54usb.h b/drivers/net/wireless/p54/p54usb.h
index 54ee738bf2af..8bc58982d8dd 100644
--- a/drivers/net/wireless/p54/p54usb.h
+++ b/drivers/net/wireless/p54/p54usb.h
@@ -126,6 +126,7 @@ struct p54u_rx_info {
 struct p54u_priv {
         struct p54_common common;
         struct usb_device *udev;
+        struct usb_interface *intf;
         enum {
                 P54U_NET2280 = 0,
                 P54U_3887