net/cdc_ncm: Increase NTB max RX/TX values to 64kb

DisplayLink ethernet devices require NTB buffers larger then 32kb
in order to run with highest performance.

This patch is changing upper limit of

net/cdc_ncm: Increase NTB max RX/TX values to 64kb

DisplayLink ethernet devices require NTB buffers larger then 32kb
in order to run with highest performance.

This patch is changing upper limit of the rx and tx buffers.
Those buffers are initialized with CDC_NCM_NTB_DEF_SIZE_RX and
CDC_NCM_NTB_DEF_SIZE_TX which is 16kb so by default no device is
affected by increased limit.

Rx and tx buffer is increased under two conditions:
- Device need to advertise that it supports higher buffer size in
dwNtbMaxInMaxSize and dwNtbMaxOutMaxSize.
- cdc_ncm/rx_max and cdc_ncm/tx_max driver parameters must be adjusted
with udev rule or ethtool.

Summary of testing and performance results:
Tests were performed on following devices:
- DisplayLink DL-3xxx family device
- DisplayLink DL-6xxx family device
- ASUS USB-C2500 2.5G USB3 ethernet adapter
- Plugable USB3 1G USB3 ethernet adapter
- EDIMAX EU-4307 USB-C ethernet adapter
- Dell DBQBCBC064 USB-C ethernet adapter

Performance measurements were done with:
- iperf3 between two linux boxes
- http://openspeedtest.com/ instance running on local test machine

Insights from tests results:
- All except one from third party usb adapters were not affected by
increased buffer size to their advertised dwNtbOutMaxSize and
dwNtbInMaxSize.
Devices were generally reaching 912-940Mbps both download and upload.

Only EDIMAX adapter experienced decreased download size from
929Mbps to 827Mbps with iper3, with openspeedtest decrease was from
968Mbps to 886Mbps.

- DisplayLink DL-3xxx family devices experienced performance increase
with iperf3 download from 300Mbps to 870Mbps and
upload from 782Mbps to 844Mbps.
With openspeedtest download increased from 556Mbps to 873Mbps
and upload from 727Mbps to 973Mbps

- DiplayLink DL-6xxx family devices are not affected by
increased buffer size.

Signed-off-by: Łukasz Spintzyk <[email protected]>
Acked-by: Greg Kroah-Hartman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>

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net: usb: cdc_ncm: use new API for bh tasklet

This converts the driver to use the new tasklet API introduced in
commit 12cc923f1ccc ("tasklet: Introduce new initialization API")

It is unfortunate t

net: usb: cdc_ncm: use new API for bh tasklet

This converts the driver to use the new tasklet API introduced in
commit 12cc923f1ccc ("tasklet: Introduce new initialization API")

It is unfortunate that we need to add a pointer to the driver context to
get back to the usbnet device, but the space will be reclaimed once
there are no more users of the old API left and we can remove the data
value and flag from the tasklet struct.

Signed-off-by: Emil Renner Berthing <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

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cdc_ncm: Implement the 32-bit version of NCM Transfer Block

The NCM specification defines two formats of transfer blocks: with 16-bit
fields (NTB-16) and with 32-bit fields (NTB-32). Currently only

cdc_ncm: Implement the 32-bit version of NCM Transfer Block

The NCM specification defines two formats of transfer blocks: with 16-bit
fields (NTB-16) and with 32-bit fields (NTB-32). Currently only NTB-16 is
implemented.

This patch adds the support of NTB-32. The motivation behind this is that
some devices such as E5785 or E5885 from the current generation of Huawei
LTE routers do not support NTB-16. The previous generations of Huawei
devices are also use NTB-32 by default.

Also this patch enables NTB-32 by default for Huawei devices.

During the 2019 ValdikSS made five attempts to contact Huawei to add the
NTB-16 support to their router firmware, but they were unsuccessful.

Signed-off-by: Alexander Bersenev <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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USB: add SPDX identifiers to all remaining files in drivers/usb/

It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the drivers/

USB: add SPDX identifiers to all remaining files in drivers/usb/

It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the drivers/usb/ and include/linux/usb* files with the correct
SPDX license identifier based on the license text in the file itself.
The SPDX identifier is a legally binding shorthand, which can be used
instead of the full boiler plate text.

This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.

Cc: Thomas Gleixner <[email protected]>
Cc: Kate Stewart <[email protected]>
Cc: Philippe Ombredanne <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Acked-by: Felipe Balbi <[email protected]>
Acked-by: Johan Hovold <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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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

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: Enrico Mioso <[email protected]>
Reported-and-tested-by: Christian Panton <[email protected]>
Reviewed-by: Bjørn Mork <[email protected]>
CC: Bjørn Mork <[email protected]>
CC: Christian Panton <[email protected]>
CC: [email protected]
CC: [email protected]
CC: Oliver Neukum <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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net: cdc_ncm: Reduce memory use when kernel memory low

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 espe

net: cdc_ncm: Reduce memory use when kernel memory low

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 <[email protected]>
Reviewed-by: Bjørn Mork <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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

Telit LE922A MBIM based composition does not work properly
with altsetting toggle done in cdc_ncm_bind_common.

This patch adds CDC_MBIM_FLA

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

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 <[email protected]>
Reviewed-by: Bjørn Mork <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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

NCM buffer sizes are negotiated with the device independently of
the network device MTU. The RX buffers are allocated by the
usbnet framewo

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

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 <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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

NCM specs are not actually mandating a specific position in the frame for
the NDP (Network Datagram Pointer). However, some Huawei devices wil

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

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 <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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net: cdc_ncm: fix 64bit division build error

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_interv

net: cdc_ncm: fix 64bit division build error

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 <[email protected]>
Signed-off-by: Bjørn Mork <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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net: cdc_ncm: remove redundant "disconnected" flag

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 <

net: cdc_ncm: remove redundant "disconnected" flag

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 <[email protected]>
Signed-off-by: Bjørn Mork <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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net: cdc_ncm: use sane defaults for rx/tx buffers

Lots of devices request much larger buffers than reasonable. This
cause real problems for users of hosts with limited resources.

Reducing the defau

net: cdc_ncm: use sane defaults for rx/tx buffers

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 <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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net: cdc_ncm/cdc_mbim: adding NCM protocol statistics

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 asymmetri

net: cdc_ncm/cdc_mbim: adding NCM protocol statistics

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 <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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net: cdc_ncm: set reasonable padding limits

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 transfer

net: cdc_ncm: set reasonable padding limits

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 <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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net: cdc_ncm: use true max dgram count for header estimates

Many newer NCM and MBIM devices will request a maximum tx
datagram count which is much smaller than our hard-coded
absolute max. We can re

net: cdc_ncm: use true max dgram count for header estimates

Many newer NCM and MBIM devices will request a maximum tx
datagram count which is much smaller than our hard-coded
absolute max. We can reduce the overhead without sacrificing
any of the simplicity for these devices, by simply using the
true negotiated count in when calculated the maximum NTH and
NDP header sizes.

Signed-off-by: Bjørn Mork <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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net: cdc_ncm: use ethtool to tune coalescing settings

Datagram coalescing is an integral part of the NCM and MBIM
protocols, intended to reduce the interrupt load primarily
on the device end of the

net: cdc_ncm: use ethtool to tune coalescing settings

Datagram coalescing is an integral part of the NCM and MBIM
protocols, intended to reduce the interrupt load primarily
on the device end of the USB link. As with all coalescing
solutions, there is a trade-off between buffering and
interrupts.

The current defaults are based on the assumption that device
side buffers should be the limiting factor. However, many
modern high speed LTE modems suffers from buffer-bloat,
making this assumption fail. This results in sub-optimal
performance due to excessive coalescing. And in cases where
such modems are connected to cheap embedded hosts there is
often severe buffer allocation issues, giving very noticeable
performance degradation .

A start on improving this is going from build time hard
coded limits to per device user configurable limits. The
ethtool coalescing API was selected as user interface
because, although the tuned values are buffer sizes, these
settings directly control datagram coalescing.

Signed-off-by: Bjørn Mork <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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net: cdc_ncm/cdc_mbim: rework probing of NCM/MBIM functions

The NCM class match in the cdc_mbim driver is confusing and
cause unexpected behaviour. The USB core guarantees that a
USB interface is in

net: cdc_ncm/cdc_mbim: rework probing of NCM/MBIM functions

The NCM class match in the cdc_mbim driver is confusing and
cause unexpected behaviour. The USB core guarantees that a
USB interface is in altsetting 0 when probing starts. This
means that devices implementing a NCM 1.0 backwards
compatible MBIM function (a "NCM/MBIM function") always hit
the NCM entry in the cdc_mbim driver match table. Such
functions will never match any of the MBIM entries.

This causes unexpeced behaviour for cases where the NCM and
MBIM entries are differet, which is currently the case for
all except Ericsson devices.

Improve the probing of NCM/MBIM functions by looking up the
device again in the cdc_mbim match table after switching to
the MBIM identity.

The shared altsetting selection is updated to better
accommodate the new probing logic, returning the preferred
altsetting for the control interface instead of the data
interface. The control interface altsetting update is moved
to the cdc_mbim driver. It is never necessary to change the
control interface altsetting for NCM.

Cc: Greg Suarez <[email protected]>
Reported by: Yu-an Shih <[email protected]>
Signed-off-by: Bjørn Mork <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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net: cdc_ncm: respect operator preferred MTU reported by MBIM

According to "Universal Serial Bus Communications Class Subclass
Specification for Mobile Broadband Interface Model, Revision 1.0,
Errat

net: cdc_ncm: respect operator preferred MTU reported by MBIM

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 <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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net: cdc_ncm: fix control message ordering

This is a context modified revert of commit 6a9612e2cb22
("net: cdc_ncm: remove ncm_parm field") which introduced
a NCM specification violation, causing se

net: cdc_ncm: fix control message ordering

This is a context modified revert of commit 6a9612e2cb22
("net: cdc_ncm: remove ncm_parm field") which introduced
a NCM specification violation, causing setup errors for
some devices. These errors resulted in the device and
host disagreeing about shared settings, with complete
failure to communicate as the end result.

The NCM specification require that many of the NCM specific
control reuests are sent only while the NCM Data Interface
is in alternate setting 0. Reverting the commit ensures that
we follow this requirement.

Fixes: 6a9612e2cb22 ("net: cdc_ncm: remove ncm_parm field")
Reported-and-tested-by: Pasi Kärkkäinen <[email protected]>
Reported-by: Thomas Schäfer <[email protected]>
Signed-off-by: Bjørn Mork <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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net: cdc_ncm: Export cdc_ncm_{tx, rx}_fixup functions for re-use

Some drivers implementing NCM-like protocols, may re-use those functions, as is
the case in the huawei_cdc_ncm driver.
Export them vi

net: cdc_ncm: Export cdc_ncm_{tx, rx}_fixup functions for re-use

Some drivers implementing NCM-like protocols, may re-use those functions, as is
the case in the huawei_cdc_ncm driver.
Export them via EXPORT_SYMBOL_GPL, in accordance with how other functions have
been exported.

Signed-off-by: Enrico Mioso <[email protected]>
Signed-off-by: Bjørn Mork <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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net: cdc_ncm: drop "extern" from header declarations

Cc: Alexey Orishko <[email protected]>
Signed-off-by: Bjørn Mork <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

net: cdc_ncm: remove descriptor pointers

header_desc was completely unused and union_desc was never used
outside cdc_ncm_bind_common.

Cc: Alexey Orishko <[email protected]>
Signed-off-by: Bj

net: cdc_ncm: remove descriptor pointers

header_desc was completely unused and union_desc was never used
outside cdc_ncm_bind_common.

Cc: Alexey Orishko <[email protected]>
Signed-off-by: Bjørn Mork <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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net: cdc_ncm: remove ncm_parm field

Moving the call to cdc_ncm_setup() after the endpoint
setup removes the last remaining reference to ncm_parm
outside cdc_ncm_setup.

Collecting all the ncm_parm b

net: cdc_ncm: remove ncm_parm field

Moving the call to cdc_ncm_setup() after the endpoint
setup removes the last remaining reference to ncm_parm
outside cdc_ncm_setup.

Collecting all the ncm_parm based calculations in
cdc_ncm_setup improves readability.

Cc: Alexey Orishko <[email protected]>
Signed-off-by: Bjørn Mork <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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net: cdc_ncm: remove tx_speed and rx_speed fields

These fields are only used to prevent printing the same speeds
multiple times if we receive multiple identical speed notifications.

The value of th

net: cdc_ncm: remove tx_speed and rx_speed fields

These fields are only used to prevent printing the same speeds
multiple times if we receive multiple identical speed notifications.

The value of these printk's is questionable, and even more so when
we filter out some of the notifications sent us by the firmware. If
we are going to print any of these, then we should print them all.

Removing little used fields is a bonus.

Cc: Alexey Orishko <[email protected]>
Signed-off-by: Bjørn Mork <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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net: cdc_ncm: remove unused udev field

We already use the usbnet udev field everywhere this could have
been used.

Cc: Alexey Orishko <[email protected]>
Signed-off-by: Bjørn Mork <bjorn@mork

net: cdc_ncm: remove unused udev field

We already use the usbnet udev field everywhere this could have
been used.

Cc: Alexey Orishko <[email protected]>
Signed-off-by: Bjørn Mork <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

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