Commit 2b02c20c authored by Enrico Mioso's avatar Enrico Mioso Committed by David S. Miller
Browse files

cdc_ncm: Set NTB format again after altsetting switch for Huawei devices 



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: default avatarEnrico Mioso <mrkiko.rs@gmail.com>
Reported-and-tested-by: default avatarChristian Panton <christian@panton.org>
Reviewed-by: default avatarBjørn Mork <bjorn@mork.no>
CC: Bjørn Mork <bjorn@mork.no>
CC: Christian Panton <christian@panton.org>
CC: linux-usb@vger.kernel.org
CC: netdev@vger.kernel.org
CC: Oliver Neukum <oliver@neukum.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 457839ed

drivers/net/usb/cdc_ncm.c

+28 −0
Original line number Diff line number Diff line
@@ -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) {

drivers/net/usb/huawei_cdc_ncm.c

+6 −0
Original line number Diff line number Diff line
@@ -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;

include/linux/usb/cdc_ncm.h

+1 −0
Original line number Diff line number Diff line
@@ -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)

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