Telit LE922A MBIM based composition does not work properly
with altsetting toggle done in cdc_ncm_bind_common.
This patch adds CDC_MBIM_FLAG_AVOID_ALTSETTING_TOGGLE quirk
to avoid this procedure that, instead, is mandatory for
other modems.
Signed-off-by: Daniele Palmas <dnlplm@xxxxxxxxx>
---
drivers/net/usb/cdc_mbim.c | 21 +++++++++++++++++++++
drivers/net/usb/cdc_ncm.c | 14 +++++++++-----
include/linux/usb/cdc_ncm.h | 3 ++-
3 files changed, 32 insertions(+), 6 deletions(-)
diff --git a/drivers/net/usb/cdc_mbim.c b/drivers/net/usb/cdc_mbim.c
index 96a5028..3a98f37 100644
--- a/drivers/net/usb/cdc_mbim.c
+++ b/drivers/net/usb/cdc_mbim.c
@@ -602,6 +602,21 @@ static const struct driver_info cdc_mbim_info_ndp_to_end = {
.data = CDC_NCM_FLAG_NDP_TO_END,
};
+/* Some modems (e.g. Telit LE922A6) do not work properly with altsetting
+ * toggle done in cdc_ncm_bind_common. CDC_MBIM_FLAG_AVOID_ALTSETTING_TOGGLE
+ * flag is used to avoid this procedure.
+ */
+static const struct driver_info cdc_mbim_info_avoid_altsetting_toggle = {
+ .description = "CDC MBIM",
+ .flags = FLAG_NO_SETINT | FLAG_MULTI_PACKET | FLAG_WWAN,
+ .bind = cdc_mbim_bind,
+ .unbind = cdc_mbim_unbind,
+ .manage_power = cdc_mbim_manage_power,
+ .rx_fixup = cdc_mbim_rx_fixup,
+ .tx_fixup = cdc_mbim_tx_fixup,
+ .data = CDC_MBIM_FLAG_AVOID_ALTSETTING_TOGGLE,
+};
+
static const struct usb_device_id mbim_devs[] = {
/* This duplicate NCM entry is intentional. MBIM devices can
* be disguised as NCM by default, and this is necessary to
@@ -626,6 +641,12 @@ static const struct usb_device_id mbim_devs[] = {
{ USB_VENDOR_AND_INTERFACE_INFO(0x12d1, USB_CLASS_COMM, USB_CDC_SUBCLASS_MBIM, USB_CDC_PROTO_NONE),
.driver_info = (unsigned long)&cdc_mbim_info_ndp_to_end,
},
+
+ /* Telit LE922A6 in MBIM composition */
+ { USB_DEVICE_AND_INTERFACE_INFO(0x1bc7, 0x1041, USB_CLASS_COMM, USB_CDC_SUBCLASS_MBIM, USB_CDC_PROTO_NONE),
+ .driver_info = (unsigned long)&cdc_mbim_info_avoid_altsetting_toggle,
+ },
+
/* default entry */
{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_MBIM, USB_CDC_PROTO_NONE),
.driver_info = (unsigned long)&cdc_mbim_info_zlp,
diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c
index 877c951..afbfc0f 100644
--- a/drivers/net/usb/cdc_ncm.c
+++ b/drivers/net/usb/cdc_ncm.c
@@ -839,11 +839,18 @@ int cdc_ncm_bind_common(struct usbnet *dev, struct usb_interface *intf, u8 data_
iface_no = ctx->data->cur_altsetting->desc.bInterfaceNumber;
+ /* Device-specific flags */
+ ctx->drvflags = drvflags;
+
/* Reset data interface. Some devices will not reset properly
* unless they are configured first. Toggle the altsetting to
- * force a reset
+ * force a reset.
+ * Some other devices do not work properly with this procedure
+ * that can be avoided using quirk CDC_MBIM_FLAG_AVOID_ALTSETTING_TOGGLE
*/
- usb_set_interface(dev->udev, iface_no, data_altsetting);
+ if (!(ctx->drvflags & CDC_MBIM_FLAG_AVOID_ALTSETTING_TOGGLE))
+ usb_set_interface(dev->udev, iface_no, data_altsetting);
+
temp = usb_set_interface(dev->udev, iface_no, 0);
if (temp) {
dev_dbg(&intf->dev, "set interface failed\n");
@@ -890,9 +897,6 @@ int cdc_ncm_bind_common(struct usbnet *dev, struct usb_interface *intf, u8 data_
/* finish setting up the device specific data */
cdc_ncm_setup(dev);
- /* Device-specific flags */
- ctx->drvflags = drvflags;
-
/* Allocate the delayed NDP if needed. */
if (ctx->drvflags & CDC_NCM_FLAG_NDP_TO_END) {
ctx->delayed_ndp16 = kzalloc(ctx->max_ndp_size, GFP_KERNEL);
diff --git a/include/linux/usb/cdc_ncm.h b/include/linux/usb/cdc_ncm.h
index 3a375d0..00d2324 100644
--- a/include/linux/usb/cdc_ncm.h
+++ b/include/linux/usb/cdc_ncm.h
@@ -81,7 +81,8 @@
#define CDC_NCM_TIMER_INTERVAL_MAX (U32_MAX / NSEC_PER_USEC)
/* Driver flags */
-#define CDC_NCM_FLAG_NDP_TO_END 0x02 /* NDP is placed at end of frame */
+#define CDC_NCM_FLAG_NDP_TO_END 0x02 /* NDP is placed at end of frame */
+#define CDC_MBIM_FLAG_AVOID_ALTSETTING_TOGGLE 0x04 /* Avoid altsetting toggle during init */
#define cdc_ncm_comm_intf_is_mbim(x) ((x)->desc.bInterfaceSubClass == USB_CDC_SUBCLASS_MBIM && \
(x)->desc.bInterfaceProtocol == USB_CDC_PROTO_NONE)
--
2.7.4
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