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authorBjørn Mork <bjorn@mork.no>2014-05-11 12:47:15 +0400
committerDavid S. Miller <davem@davemloft.net>2014-05-14 01:46:09 +0400
commit50a0ffaf75e9d2d97200b523f2c600f40e9756b1 (patch)
tree6ffcf988584c3725a7e146afae06e9cd11ac2355 /drivers/net/usb/cdc_mbim.c
parenta563babeb5fbe721a046adf6f1cdc02e0a207c8d (diff)
downloadlinux-50a0ffaf75e9d2d97200b523f2c600f40e9756b1.tar.xz
net: cdc_ncm/cdc_mbim: rework probing of NCM/MBIM functions
The NCM class match in the cdc_mbim driver is confusing and cause unexpected behaviour. The USB core guarantees that a USB interface is in altsetting 0 when probing starts. This means that devices implementing a NCM 1.0 backwards compatible MBIM function (a "NCM/MBIM function") always hit the NCM entry in the cdc_mbim driver match table. Such functions will never match any of the MBIM entries. This causes unexpeced behaviour for cases where the NCM and MBIM entries are differet, which is currently the case for all except Ericsson devices. Improve the probing of NCM/MBIM functions by looking up the device again in the cdc_mbim match table after switching to the MBIM identity. The shared altsetting selection is updated to better accommodate the new probing logic, returning the preferred altsetting for the control interface instead of the data interface. The control interface altsetting update is moved to the cdc_mbim driver. It is never necessary to change the control interface altsetting for NCM. Cc: Greg Suarez <gsuarez@smithmicro.com> Reported by: Yu-an Shih <yshih@nvidia.com> Signed-off-by: Bjørn Mork <bjorn@mork.no> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/usb/cdc_mbim.c')
-rw-r--r--drivers/net/usb/cdc_mbim.c43
1 files changed, 41 insertions, 2 deletions
diff --git a/drivers/net/usb/cdc_mbim.c b/drivers/net/usb/cdc_mbim.c
index 80d27719ba38..bc23273d0455 100644
--- a/drivers/net/usb/cdc_mbim.c
+++ b/drivers/net/usb/cdc_mbim.c
@@ -107,15 +107,54 @@ static const struct net_device_ops cdc_mbim_netdev_ops = {
.ndo_vlan_rx_kill_vid = cdc_mbim_rx_kill_vid,
};
+/* Change the control interface altsetting and update the .driver_info
+ * pointer if the matching entry after changing class codes points to
+ * a different struct
+ */
+static int cdc_mbim_set_ctrlalt(struct usbnet *dev, struct usb_interface *intf, u8 alt)
+{
+ struct usb_driver *driver = to_usb_driver(intf->dev.driver);
+ const struct usb_device_id *id;
+ struct driver_info *info;
+ int ret;
+
+ ret = usb_set_interface(dev->udev,
+ intf->cur_altsetting->desc.bInterfaceNumber,
+ alt);
+ if (ret)
+ return ret;
+
+ id = usb_match_id(intf, driver->id_table);
+ if (!id)
+ return -ENODEV;
+
+ info = (struct driver_info *)id->driver_info;
+ if (info != dev->driver_info) {
+ dev_dbg(&intf->dev, "driver_info updated to '%s'\n",
+ info->description);
+ dev->driver_info = info;
+ }
+ return 0;
+}
+
static int cdc_mbim_bind(struct usbnet *dev, struct usb_interface *intf)
{
struct cdc_ncm_ctx *ctx;
struct usb_driver *subdriver = ERR_PTR(-ENODEV);
int ret = -ENODEV;
- u8 data_altsetting = cdc_ncm_select_altsetting(dev, intf);
+ u8 data_altsetting = 1;
struct cdc_mbim_state *info = (void *)&dev->data;
- /* Probably NCM, defer for cdc_ncm_bind */
+ /* should we change control altsetting on a NCM/MBIM function? */
+ if (cdc_ncm_select_altsetting(intf) == CDC_NCM_COMM_ALTSETTING_MBIM) {
+ data_altsetting = CDC_NCM_DATA_ALTSETTING_MBIM;
+ ret = cdc_mbim_set_ctrlalt(dev, intf, CDC_NCM_COMM_ALTSETTING_MBIM);
+ if (ret)
+ goto err;
+ ret = -ENODEV;
+ }
+
+ /* we will hit this for NCM/MBIM functions if prefer_mbim is false */
if (!cdc_ncm_comm_intf_is_mbim(intf->cur_altsetting))
goto err;