Some firmwares in Huawei E3372H devices have been observed to switch back
to NTB 32-bit format after altsetting switch.
This patch implements a driver flag to check for the device settings and
set NTB format to 16-bit again if needed.
The flag has been activated for devices controlled by the huawei_cdc_ncm.c
driver.
V1->V2:
- fixed broken error checks
- some corrections to the commit message
V2->V3:
- variable name changes, to clarify what's happening
- check (and possibly set) the NTB format later in the common bind code path
Signed-off-by: Enrico Mioso <mrkiko.rs@xxxxxxxxx>
Reported-and-tested-by: Christian Panton <christian@xxxxxxxxxx>
Reviewed-by: Bjørn Mork <bjorn@xxxxxxx>
CC: Bjørn Mork <bjorn@xxxxxxx>
CC: Christian Panton <christian@xxxxxxxxxx>
CC: linux-usb@xxxxxxxxxxxxxxx
CC: netdev@xxxxxxxxxxxxxxx
CC: Oliver Neukum <oliver@xxxxxxxxxx>
---
drivers/net/usb/cdc_ncm.c | 28 ++++++++++++++++++++++++++++
drivers/net/usb/huawei_cdc_ncm.c | 6 ++++++
include/linux/usb/cdc_ncm.h | 1 +
3 files changed, 35 insertions(+)
diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c
index d103a1d4fb36..8f572b9f3625 100644
--- a/drivers/net/usb/cdc_ncm.c
+++ b/drivers/net/usb/cdc_ncm.c
@@ -768,8 +768,10 @@ int cdc_ncm_bind_common(struct usbnet *dev, struct usb_interface *intf, u8 data_
u8 *buf;
int len;
int temp;
+ int err;
u8 iface_no;
struct usb_cdc_parsed_header hdr;
+ u16 curr_ntb_format;
ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
if (!ctx)
@@ -874,6 +876,32 @@ int cdc_ncm_bind_common(struct usbnet *dev, struct usb_interface *intf, u8 data_
goto error2;
}
+ /*
+ * Some Huawei devices have been observed to come out of reset in NDP32 mode.
+ * Let's check if this is the case, and set the device to NDP16 mode again if
+ * needed.
+ */
+ if (ctx->drvflags & CDC_NCM_FLAG_RESET_NTB16) {
+ err = usbnet_read_cmd(dev, USB_CDC_GET_NTB_FORMAT,
+ USB_TYPE_CLASS | USB_DIR_IN | USB_RECIP_INTERFACE,
+ 0, iface_no, &curr_ntb_format, 2);
+ if (err < 0) {
+ goto error2;
+ }
+
+ if (curr_ntb_format == USB_CDC_NCM_NTB32_FORMAT) {
+ dev_info(&intf->dev, "resetting NTB format to 16-bit");
+ err = usbnet_write_cmd(dev, USB_CDC_SET_NTB_FORMAT,
+ USB_TYPE_CLASS | USB_DIR_OUT
+ | USB_RECIP_INTERFACE,
+ USB_CDC_NCM_NTB16_FORMAT,
+ iface_no, NULL, 0);
+
+ if (err < 0)
+ goto error2;
+ }
+ }
+
cdc_ncm_find_endpoints(dev, ctx->data);
cdc_ncm_find_endpoints(dev, ctx->control);
if (!dev->in || !dev->out || !dev->status) {
diff --git a/drivers/net/usb/huawei_cdc_ncm.c b/drivers/net/usb/huawei_cdc_ncm.c
index 2680a65cd5e4..63f28908afda 100644
--- a/drivers/net/usb/huawei_cdc_ncm.c
+++ b/drivers/net/usb/huawei_cdc_ncm.c
@@ -80,6 +80,12 @@ static int huawei_cdc_ncm_bind(struct usbnet *usbnet_dev,
* be at the end of the frame.
*/
drvflags |= CDC_NCM_FLAG_NDP_TO_END;
+
+ /* Additionally, it has been reported that some Huawei E3372H devices, with
+ * firmware version 21.318.01.00.541, come out of reset in NTB32 format mode, hence
+ * needing to be set to the NTB16 one again.
+ */
+ drvflags |= CDC_NCM_FLAG_RESET_NTB16;
ret = cdc_ncm_bind_common(usbnet_dev, intf, 1, drvflags);
if (ret)
goto err;
diff --git a/include/linux/usb/cdc_ncm.h b/include/linux/usb/cdc_ncm.h
index 021f7a88f52c..1a59699cf82a 100644
--- a/include/linux/usb/cdc_ncm.h
+++ b/include/linux/usb/cdc_ncm.h
@@ -83,6 +83,7 @@
/* Driver flags */
#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_FLAG_RESET_NTB16 0x08 /* set NDP16 one more time after altsetting switch */
#define cdc_ncm_comm_intf_is_mbim(x) ((x)->desc.bInterfaceSubClass == USB_CDC_SUBCLASS_MBIM && \
(x)->desc.bInterfaceProtocol == USB_CDC_PROTO_NONE)
--
2.13.2
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