kernel/drivers/net/usb/huawei_cdc_ncm.c, branch linux-4.3.y

cdc_ncm: Add support for moving NDP to end of NCM frame

2015-07-09T21:58:31Z

NCM specs are not actually mandating a specific position in the frame for the NDP (Network Datagram Pointer). However, some Huawei devices will ignore our aggregates if it is not placed after the datagrams it points to. Add support for doing just this, in a per-device configurable way. While at it, update NCM subdrivers, disabling this functionality in all of them, except in huawei_cdc_ncm where it is enabled instead. We aren't making any distinction between different Huawei NCM devices, based on what the vendor driver does. Standard NCM devices are left unaffected: if they are compliant, they should be always usable, still stay on the safe side. This change has been tested and working with a Huawei E3131 device (which works regardless of NDP position), a Huawei E3531 (also working both ways) and an E3372 (which mandates NDP to be after indexed datagrams). V1->V2: - corrected wrong NDP acronym definition - fixed possible NULL pointer dereference - patch cleanup V2->V3: - Properly account for the NDP size when writing new packets to SKB Signed-off-by: Enrico Mioso Signed-off-by: David S. Miller

net: huawei_cdc_ncm: add "subclass 3" devices

2014-07-17T23:49:50Z

Huawei's usage of the subclass and protocol fields is not 100% clear to us, but there appears to be a very strict system. A device with the "shared" device ID 12d1:1506 and this NCM function was recently reported (showing only default altsetting): Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 1 bAlternateSetting 0 bNumEndpoints 1 bInterfaceClass 255 Vendor Specific Class bInterfaceSubClass 3 bInterfaceProtocol 22 iInterface 8 CDC Network Control Model (NCM) ** UNRECOGNIZED: 05 24 00 10 01 ** UNRECOGNIZED: 06 24 1a 00 01 1f ** UNRECOGNIZED: 0c 24 1b 00 01 00 04 10 14 dc 05 20 ** UNRECOGNIZED: 0d 24 0f 0a 0f 00 00 00 ea 05 03 00 01 ** UNRECOGNIZED: 05 24 06 01 01 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x85 EP 5 IN bmAttributes 3 Transfer Type Interrupt Synch Type None Usage Type Data wMaxPacketSize 0x0010 1x 16 bytes bInterval 9 Cc: Enrico Mioso Signed-off-by: Bjørn Mork Signed-off-by: David S. Miller

net: huawei_cdc_ncm: increase command buffer size

2014-06-22T02:33:17Z

Messages from the modem exceeding 256 bytes cause communication failure. The WDM protocol is strictly "read on demand", meaning that we only poll for unread data after receiving a notification from the modem. Since we have no way to know how much data the modem has to send, we must make sure that the buffer we provide is "big enough". Message truncation does not work. Truncated messages are left unread until the modem has another message to send. Which often won't happen until the userspace application has given up waiting for the final part of the last message, and therefore sends another command. With a proper CDC WDM function there is a descriptor telling us which buffer size the modem uses. But with this vendor specific implementation there is no known way to calculate the exact "big enough" number. It is an unknown property of the modem firmware. Experience has shown that 256 is too small. The discussion of this failure ended up concluding that 512 might be too small as well. So 1024 seems like a reasonable value for now. Fixes: 41c47d8cfd68 ("net: huawei_cdc_ncm: Introduce the huawei_cdc_ncm driver") Cc: Enrico Mioso Reported-by: Dan Williams Signed-off-by: Bjørn Mork Acked-By: Enrico Mioso Tested-by: Dan Williams Signed-off-by: David S. Miller

net: cdc_ncm: remove redundant "disconnected" flag

2014-05-17T02:39:02Z

Calling netif_carrier_{on,off} is sufficient. There is no need to duplicate the carrier state in a driver specific flag. Acked-by: Enrico Mioso Signed-off-by: Bjørn Mork Signed-off-by: David S. Miller

net: huawei_cdc_ncm: Introduce the huawei_cdc_ncm driver

2013-11-05T20:21:25Z

This driver supports devices using the NCM protocol as an encapsulation layer for other protocols, like the E3131 Huawei 3G modem. This drivers approach was heavily inspired by the qmi_wwan/cdc_mbim approach & code model. Signed-off-by: Enrico Mioso Signed-off-by: Bjørn Mork Signed-off-by: David S. Miller