user/sven/linux.git/include/linux/usb/cdc_ncm.h, branch stable/4.13.y

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

2017-07-14T15:15:05Z

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 Reported-and-tested-by: Christian Panton Reviewed-by: Bjørn Mork CC: Bjørn Mork CC: Christian Panton CC: linux-usb@vger.kernel.org CC: netdev@vger.kernel.org CC: Oliver Neukum Signed-off-by: David S. Miller

net: cdc_ncm: Reduce memory use when kernel memory low

2017-07-03T08:50:49Z

The CDC-NCM driver can require large amounts of memory to create skb's and this can be a problem when the memory becomes fragmented. This especially affects embedded systems that have constrained resources but wish to maximise the throughput of CDC-NCM with 16KiB NTB's. The issue is after running for a while the kernel memory can become fragmented and it needs compacting. If the NTB allocation is needed before the memory has been compacted the atomic allocation can fail which can cause increased latency, large re-transmissions or disconnections depending upon the data being transmitted at the time. This situation occurs for less than a second until the kernel has compacted the memory but the failed devices can take a lot longer to recover from the failed TX packets. To ease this temporary situation I modified the CDC-NCM TX path to temporarily switch into a reduced memory mode which allocates an NTB that will fit into a USB_CDC_NCM_NTB_MIN_OUT_SIZE (default 2048 Bytes) sized memory block and only transmit NTB's with a single network frame until the memory situation is resolved. Each time this issue occurs we wait for an increasing number of reduced size allocations before requesting a full size one to not put additional pressure on a low memory system. Once the memory is compacted the CDC-NCM data can resume transmitting at the normal tx_max rate once again. Signed-off-by: Jim Baxter Reviewed-by: Bjørn Mork Signed-off-by: David S. Miller

NET: usb: cdc_mbim: add quirk for supporting Telit LE922A

2016-12-08T18:02:25Z

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 Reviewed-by: Bjørn Mork Signed-off-by: David S. Miller

net: cdc_ncm: avoid changing RX/TX buffers on MTU changes

2015-12-24T03:52:08Z

NCM buffer sizes are negotiated with the device independently of the network device MTU. The RX buffers are allocated by the usbnet framework based on the rx_urb_size value set by cdc_ncm. A single RX buffer can hold a number of MTU sized packets. The default usbnet change_mtu ndo only modifies rx_urb_size if it is equal to hard_mtu. And the cdc_ncm driver will set rx_urb_size and hard_mtu independently of each other, based on dwNtbInMaxSize and dwNtbOutMaxSize respectively. It was therefore assumed that usbnet_change_mtu() would never touch rx_urb_size. This failed to consider the case where dwNtbInMaxSize and dwNtbOutMaxSize happens to be equal. Fix by implementing an NCM specific change_mtu ndo, modifying the netdev MTU without touching the buffer size settings. Signed-off-by: Bjørn Mork Signed-off-by: David S. Miller

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: cdc_ncm: fix 64bit division build error

2014-05-21T05:56:06Z

The upper timer_interval limit is arbitrary and much higher than anything usable in the real world. Reducing it from 15s to ~4s to make the timer_interval fit in an u32 does not make much difference. The limit is still outside the practical bounds. This eliminates the need for a 64bit timer_interval, fixing a build error related to 64bit division: drivers/built-in.o: In function `cdc_ncm_get_coalesce': ak8975.c:(.text+0x1ac994): undefined reference to `__aeabi_uldivmod' Reported-by: Stephen Rothwell Signed-off-by: Bjørn Mork 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: cdc_ncm: use sane defaults for rx/tx buffers

2014-05-17T02:39:02Z

Lots of devices request much larger buffers than reasonable. This cause real problems for users of hosts with limited resources. Reducing the default buffer size to 16kB for such devices is a reasonable trade-off between allowing them to aggregate traffic and avoiding memory exhaustion on resource restrained hosts. Signed-off-by: Bjørn Mork Signed-off-by: David S. Miller

net: cdc_ncm/cdc_mbim: adding NCM protocol statistics

2014-05-17T02:39:01Z

To have an idea of the effects of the protocol coalescing it's useful to have some counters showing the different aspects. Due to the asymmetrical usbnet interface the netdev rx_bytes counter has been counting real received payload, while the tx_bytes counter has included the NCM/MBIM framing overhead. This overhead can be many times the payload because of the aggressive padding strategy of this driver, and will vary a lot depending on device and traffic. With very few exceptions, users are only interested in the payload size. Having an somewhat accurate payload byte counter is particularly important for mobile broadband devices, which many NCM devices and of course all MBIM devices are. Users and userspace applications will use this counter to monitor account quotas. Having protocol specific counters for the overhead, we are now able to correct the tx_bytes netdev counter so that it shows the real payload Signed-off-by: Bjørn Mork Signed-off-by: David S. Miller

net: cdc_ncm: set reasonable padding limits

2014-05-17T02:39:01Z

We pad frames larger than X to maximum size for devices which don't need a ZLP after maximum sized frames. This allows the device to optimize its transfers for one fixed buffer size. X was arbitrarily set at 512 bytes regardless of real buffer maximum, causing extreme overheads due to excessive padding of larger tx buffers. Limit the padding to at most 3 full USB packets, still allowing the overhead to payload ratio of 3/1. Signed-off-by: Bjørn Mork Signed-off-by: David S. Miller