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path: root/drivers/net/usb/cdc_ncm.c
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Diffstat (limited to 'drivers/net/usb/cdc_ncm.c')
-rw-r--r--drivers/net/usb/cdc_ncm.c27
1 files changed, 27 insertions, 0 deletions
diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c
index 71b6e92..4041159 100644
--- a/drivers/net/usb/cdc_ncm.c
+++ b/drivers/net/usb/cdc_ncm.c
@@ -344,6 +344,23 @@ static const struct ethtool_ops cdc_ncm_ethtool_ops = {
.nway_reset = usbnet_nway_reset,
};
+/* return first slave interface if an IAD matches the given master */
+static struct usb_interface *get_iad_slave(struct usb_device *udev,
+ struct usb_interface *master) {
+ int i;
+ struct usb_interface_assoc_descriptor *iad;
+ u8 mnum = master->cur_altsetting->desc.bInterfaceNumber;
+
+ for (i = 0; i < USB_MAXIADS; i++) {
+ iad = udev->actconfig->intf_assoc[i];
+ if (!iad)
+ break;
+ if (iad->bFirstInterface == mnum && iad->bInterfaceCount == 2)
+ return usb_ifnum_to_if(udev, mnum + 1);
+ }
+ return NULL;
+}
+
int cdc_ncm_bind_common(struct usbnet *dev, struct usb_interface *intf, u8 data_altsetting)
{
struct cdc_ncm_ctx *ctx;
@@ -435,6 +452,16 @@ advance:
len -= temp;
}
+ /* some buggy devices have an IAD but no CDC Union */
+ if (!ctx->union_desc) {
+ dev_dbg(&intf->dev, "missing CDC Union descriptor\n");
+ ctx->data = get_iad_slave(dev->udev, intf);
+ if (ctx->data) {
+ ctx->control = intf;
+ dev_dbg(&intf->dev, "got slave from IAD\n");
+ }
+ }
+
/* check if we got everything */
if ((ctx->control == NULL) || (ctx->data == NULL) ||
((!ctx->mbim_desc) && ((ctx->ether_desc == NULL) || (ctx->control != intf))))
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