[PATCH 1/2] USB: cdc: add MBIM extended functional descriptor structure

Subsystems: the rest, usb cdc ethernet driver, usb subsystem

STALE4568d

3 messages, 2 authors, 2014-03-17 · open the first message on its own page

[PATCH 1/2] USB: cdc: add MBIM extended functional descriptor structure

From: Ben Chan <hidden>
Date: 2014-03-16 06:56:13

This patch adds the MBIM extended functional descriptor structure
defined in "Universal Serial Bus Communications Class Subclass
Specification for Mobile Broadband Interface Model, Revision 1.0,
Errata-1" published by USB-IF.

Signed-off-by: Ben Chan <redacted>
---
 include/uapi/linux/usb/cdc.h | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/include/uapi/linux/usb/cdc.h b/include/uapi/linux/usb/cdc.h
index f35aa0a..b6a9cdd 100644
--- a/include/uapi/linux/usb/cdc.h
+++ b/include/uapi/linux/usb/cdc.h

@@ -56,6 +56,7 @@
 #define USB_CDC_OBEX_TYPE		0x15
 #define USB_CDC_NCM_TYPE		0x1a
 #define USB_CDC_MBIM_TYPE		0x1b
+#define USB_CDC_MBIM_EXTENDED_TYPE	0x1c
 
 /* "Header Functional Descriptor" from CDC spec  5.2.3.1 */
 struct usb_cdc_header_desc {

@@ -205,6 +206,17 @@ struct usb_cdc_mbim_desc {
 	__u8    bmNetworkCapabilities;
 } __attribute__ ((packed));
 
+/* "MBIM Extended Functional Descriptor" from CDC MBIM spec 1.0 errata-1 */
+struct usb_cdc_mbim_extended_desc {
+	__u8	bLength;
+	__u8	bDescriptorType;
+	__u8	bDescriptorSubType;
+
+	__le16	bcdMBIMExtendedVersion;
+	__u8	bMaxOutstandingCommandMessages;
+	__le16	wMTU;
+} __attribute__ ((packed));
+
 /*-------------------------------------------------------------------------*/
 
 /*

-- 
1.9.0.279.gdc9e3eb

[PATCH 2/2] net: cdc_ncm: respect operator preferred MTU reported by MBIM

From: Ben Chan <hidden>
Date: 2014-03-16 06:49:13

According to "Universal Serial Bus Communications Class Subclass
Specification for Mobile Broadband Interface Model, Revision 1.0,
Errata-1" published by USB-IF, the wMTU field of the MBIM extended
functional descriptor indicates the operator preferred MTU for IP data
streams.

This patch modifies cdc_ncm_setup to ensure that the MTU value set on
the usbnet device does not exceed the operator preferred MTU indicated
by wMTU if the MBIM device exposes a MBIM extended functional
descriptor.

Signed-off-by: Ben Chan <redacted>
---
 drivers/net/usb/cdc_ncm.c   | 15 +++++++++++++++
 include/linux/usb/cdc_ncm.h |  1 +
 2 files changed, 16 insertions(+)

diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c
index dbff290..0b036ed 100644
--- a/drivers/net/usb/cdc_ncm.c
+++ b/drivers/net/usb/cdc_ncm.c

@@ -261,6 +261,13 @@ out:
 	/* set MTU to max supported by the device if necessary */
 	if (dev->net->mtu > ctx->max_datagram_size - eth_hlen)
 		dev->net->mtu = ctx->max_datagram_size - eth_hlen;
+
+	/* do not exceed operater preferred MTU */
+	if (ctx->mbim_extended_desc &&
+		ctx->mbim_extended_desc->wMTU != 0 &&
+		dev->net->mtu > ctx->mbim_extended_desc->wMTU)
+		dev->net->mtu = ctx->mbim_extended_desc->wMTU;
+
 	return 0;
 }

@@ -399,6 +406,14 @@ int cdc_ncm_bind_common(struct usbnet *dev, struct usb_interface *intf, u8 data_
 			ctx->mbim_desc = (const struct usb_cdc_mbim_desc *)buf;
 			break;
 
+		case USB_CDC_MBIM_EXTENDED_TYPE:
+			if (buf[0] < sizeof(*(ctx->mbim_extended_desc)))
+				break;
+
+			ctx->mbim_extended_desc =
+				(const struct usb_cdc_mbim_extended_desc *)buf;
+			break;
+
 		default:
 			break;
 		}

diff --git a/include/linux/usb/cdc_ncm.h b/include/linux/usb/cdc_ncm.h
index c3fa807..bdf05fb 100644
--- a/include/linux/usb/cdc_ncm.h
+++ b/include/linux/usb/cdc_ncm.h

@@ -93,6 +93,7 @@ struct cdc_ncm_ctx {
 
 	const struct usb_cdc_ncm_desc *func_desc;
 	const struct usb_cdc_mbim_desc *mbim_desc;
+	const struct usb_cdc_mbim_extended_desc *mbim_extended_desc;
 	const struct usb_cdc_ether_desc *ether_desc;
 
 	struct usb_interface *control;

-- 
1.9.0.279.gdc9e3eb

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Re: [PATCH 1/2] USB: cdc: add MBIM extended functional descriptor structure

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2014-03-17 23:05:41

On Sat, Mar 15, 2014 at 11:49:09PM -0700, Ben Chan wrote:

This patch adds the MBIM extended functional descriptor structure
defined in "Universal Serial Bus Communications Class Subclass
Specification for Mobile Broadband Interface Model, Revision 1.0,
Errata-1" published by USB-IF.

Signed-off-by: Ben Chan <redacted>
---
 include/uapi/linux/usb/cdc.h | 12 ++++++++++++
 1 file changed, 12 insertions(+)

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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