This function does nothing so remove it. This addresses the following
coccicheck warning:

drivers/net/wireless/broadcom/brcm80211/brcmsmac/main.c:5103:6-15:
Unneeded variable: "callbacks". Return "0" on line 5105
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200910140446.1168049-1-yanaijie@huawei.com
Link: https://lore.kernel.org/r/20200910140455.1168174-1-yanaijie@huawei.com

Fixes the following W=1 kernel build warning(s):

 drivers/net/wireless/broadcom/brcm80211/brcmsmac/phy/phy_lcn.c:361:25: warning: unused variable 'lcnphy_rx_iqcomp_table_rev0' [-Wunused-const-variable]
 struct lcnphy_rx_iqcomp lcnphy_rx_iqcomp_table_rev0[] = {
                         ^
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200910065431.657636-30-lee.jones@linaro.org
Link: https://lore.kernel.org/r/20200910140505.1168317-1-yanaijie@huawei.com
Link: https://lore.kernel.org/r/20200910035600.21736-1-yuehaibing@huawei.com

Fixes the following W=1 kernel build warning(s):

 drivers/net/wireless/broadcom/brcm80211/brcmsmac/phy/phytbl_lcn.c:108:18: warning: unused variable 'dot11lcn_gain_tbl_rev1' [-Wunused-const-variable]
 static const u32 dot11lcn_gain_tbl_rev1[] = {
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200910065431.657636-29-lee.jones@linaro.org

The wrappers in include/linux/pci-dma-compat.h should go away.

The patch has been generated with the coccinelle script below and has been
hand modified to replace GFP_ with a correct flag.
It has been compile tested.

When memory is allocated in 'mpi_map_card()' GFP_KERNEL can be used because
this function is called from a probe or a module_init() function and no
spinlock is taken in the between.

The call chains are:
  airo_init_module				module_init function in 'airo.c'
or
  airo_probe				.probe function in 'airo_cs.c'
    --> airo_config

followed in both cases by:
      --> init_airo_card
        --> _init_airo_card
          --> mpi_map_card

@@
@@
-    PCI_DMA_BIDIRECTIONAL
+    DMA_BIDIRECTIONAL

@@
@@
-    PCI_DMA_TODEVICE
+    DMA_TO_DEVICE

@@
@@
-    PCI_DMA_FROMDEVICE
+    DMA_FROM_DEVICE

@@
@@
-    PCI_DMA_NONE
+    DMA_NONE

@@
expression e1, e2, e3;
@@
-    pci_alloc_consistent(e1, e2, e3)
+    dma_alloc_coherent(&e1->dev, e2, e3, GFP_)

@@
expression e1, e2, e3;
@@
-    pci_zalloc_consistent(e1, e2, e3)
+    dma_alloc_coherent(&e1->dev, e2, e3, GFP_)

@@
expression e1, e2, e3, e4;
@@
-    pci_free_consistent(e1, e2, e3, e4)
+    dma_free_coherent(&e1->dev, e2, e3, e4)

@@
expression e1, e2, e3, e4;
@@
-    pci_map_single(e1, e2, e3, e4)
+    dma_map_single(&e1->dev, e2, e3, e4)

@@
expression e1, e2, e3, e4;
@@
-    pci_unmap_single(e1, e2, e3, e4)
+    dma_unmap_single(&e1->dev, e2, e3, e4)

@@
expression e1, e2, e3, e4, e5;
@@
-    pci_map_page(e1, e2, e3, e4, e5)
+    dma_map_page(&e1->dev, e2, e3, e4, e5)

@@
expression e1, e2, e3, e4;
@@
-    pci_unmap_page(e1, e2, e3, e4)
+    dma_unmap_page(&e1->dev, e2, e3, e4)

@@
expression e1, e2, e3, e4;
@@
-    pci_map_sg(e1, e2, e3, e4)
+    dma_map_sg(&e1->dev, e2, e3, e4)

@@
expression e1, e2, e3, e4;
@@
-    pci_unmap_sg(e1, e2, e3, e4)
+    dma_unmap_sg(&e1->dev, e2, e3, e4)

@@
expression e1, e2, e3, e4;
@@
-    pci_dma_sync_single_for_cpu(e1, e2, e3, e4)
+    dma_sync_single_for_cpu(&e1->dev, e2, e3, e4)

@@
expression e1, e2, e3, e4;
@@
-    pci_dma_sync_single_for_device(e1, e2, e3, e4)
+    dma_sync_single_for_device(&e1->dev, e2, e3, e4)

@@
expression e1, e2, e3, e4;
@@
-    pci_dma_sync_sg_for_cpu(e1, e2, e3, e4)
+    dma_sync_sg_for_cpu(&e1->dev, e2, e3, e4)

@@
expression e1, e2, e3, e4;
@@
-    pci_dma_sync_sg_for_device(e1, e2, e3, e4)
+    dma_sync_sg_for_device(&e1->dev, e2, e3, e4)

@@
expression e1, e2;
@@
-    pci_dma_mapping_error(e1, e2)
+    dma_mapping_error(&e1->dev, e2)

@@
expression e1, e2;
@@
-    pci_set_dma_mask(e1, e2)
+    dma_set_mask(&e1->dev, e2)

@@
expression e1, e2;
@@
-    pci_set_consistent_dma_mask(e1, e2)
+    dma_set_coherent_mask(&e1->dev, e2)
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200907201942.321568-1-christophe.jaillet@wanadoo.fr

Firmware may have SAE authenticator code built-in. This is detected by
the driver and indicated in the wiphy features flags. User space can use
this flag to determine whether or not to provide the password material
in the nl80211 start AP command to offload the SAE authentication in AP
mode.
Signed-off-by: Chung-Hsien Hsu <stanley.hsu@cypress.com>
Signed-off-by: Chi-Hsien Lin <chi-hsien.lin@cypress.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200817073316.33402-5-stanley.hsu@cypress.com

Firmware may have authenticator code built-in. This is detected by the
driver and indicated in the wiphy features flags. User space can use
this flag to determine whether or not to provide the pre-shared key
material in the nl80211 start AP command to offload the 4-way handshake
in AP mode.
Signed-off-by: Chung-Hsien Hsu <stanley.hsu@cypress.com>
Signed-off-by: Chi-Hsien Lin <chi-hsien.lin@cypress.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200817073316.33402-3-stanley.hsu@cypress.com

Rather than doing request_irq and then disabling the irq immediately, it
should be safer to use IRQ_NOAUTOEN flag for the irq. It removes any gap
between request_irq() and disable_irq().

Cc: Salil Mehta <salil.mehta@huawei.com>
Reviewed-by: Yunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Grygorii Strashko says:

====================
net: ethernet: ti: ale: add static configuration

As existing, as newly introduced CPSW ALE versions have differences in
supported features and ALE table formats. Especially it's actual for the
recent AM65x/J721E/J7200 and future AM64x SoCs, which supports more
features like: auto-aging, classifiers, Link aggregation, additional HW
filtering, etc.

The existing ALE configuration interface is not practical in terms of
adding new features and requires consumers to program a lot static
parameters. And any attempt to add new features will case endless adding
and maintaining different combination of flags and options. Because CPSW
ALE configuration is static and fixed for SoC (or set of SoC), It is
reasonable to add support for static ALE configurations inside ALE module.

This series introduces static ALE configuration table for different ALE
variants and provides option for consumers to select required ALE
configuration by providing ALE const char *dev_id identifier (Patch 2).
And all existing driver have been switched to use new approach (Patches 3-6).

After this ALE HW auto-ageing feature can be enabled for AM65x CPSW ALE
variant (Patch 7).

Finally, Patches 8-9 introduces tables to describe the ALE VLAN entries
fields as the ALE VLAN entries are too much differ between different TI
CPSW ALE versions. So, handling them using flags, defines and get/set
functions are became over-complicated.

Patch 1 - is preparation patch

Changes in v3:
- fixed comment for Patch 2

Changes in v2:
- fixed sparse warnings

v2: https://lore.kernel.org/patchwork/cover/1301684/
v1: https://lore.kernel.org/patchwork/cover/1301048/
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

The TI J721E (CPSW9g) ALE version is similar, in general, to Sitara AM3/4/5
CPSW ALE, but has more extended functions and different ALE VLAN entry
format.

This patch adds support for for multi port TI J721E (CPSW9g) ALE variant.
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The ALE VLAN entries are too much differ between different TI CPSW ALE
versions. So, handling them using flags, defines and get/set functions
became over-complicated.

This patch introduces tables to describe the ALE VLAN entries fields, which
are different between TI CPSW ALE versions, and new get/set access
functions. It also allows to detect incorrect access to not available ALL
entry fields.
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The AM65x ALE supports HW auto-ageing which can be enabled by programming
ageing interval in ALE_AGING_TIMER register. For this CPSW fck_clk
frequency has to be know by ALE.

This patch extends cpsw_ale_params with bus_freq field and enables ALE HW
auto ageing for AM65x CPSW2G ALE version.
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Hence all existing driver updated to use ALE dev_id the usage of ale dev_id
can be made mandatory and cpsw_ale_create() can be updated to use
"features" property from ALE static configuration.
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The previous patch has introduced possibility to select CPSW ALE by using
ALE dev_id identifier. Switch TI TI AM65x/J721E CPSW NUSS driver to use
dev_id.
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The previous patch has introduced possibility to select CPSW ALE by using
ALE dev_id identifier. Switch TI Keystone 2 NETCP driver to use dev_id and
perform clean up by removing "ale_entries" configuration code.
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The previous patch has introduced possibility to select CPSW ALE by using
ALE dev_id identifier. Switch TI cpsw driver to use dev_id="cpsw" and
perform clean up by removing "ale_entries" configuration code.
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

As existing, as newly introduced CPSW ALE versions have differences in
supported features and ALE table formats. Especially it's actual for the
recent AM65x/J721E/J7200 SoC and feature AM64x, which supports features
like: auto-aging, classifiers, Link aggregation, additional hw filtering,
etc.

Existing ALE configuration interface is not practical in terms of adding
new features and requires consumers to program a lot static parameters. Any
attempt to add new options will case endless adding and maintaining
different combination of flags and options.

Hence CPSW ALE configuration is static and fixed for SoC (or set of SoC) It
is reasonable to add support for static ALE configurations inside ALE
module. This patch adds static ALE configuration table for different ALE
versions and provides option for consumers to select required ALE
configuration by providing ALE const char *dev_id identifier.

This feature is not enabled by default until existing CPSW drivers will be
modified by follow up patches.
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add cpsw_ale_get_num_entries() API to return number of ALE table entries
and update existing drivers to use it.
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Vladimir Oltean says:

====================
DSA tag_8021q cleanup

This small series tries to consolidate the VLAN handling in DSA a little
bit. It reworks tag_8021q to be minimally invasive to the dsa_switch_ops
structure. This makes the rest of the code a bit easier to follow.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

This reverts commit 314f76d7.

Citing that commit message, the call graph was:

    dsa_slave_vlan_rx_add_vid   dsa_port_setup_8021q_tagging
                |                        |
                |                        |
                |          +-------------+
                |          |
                v          v
               dsa_port_vid_add      dsa_slave_port_obj_add
                      |                         |
                      +-------+         +-------+
                              |         |
                              v         v
                           dsa_port_vlan_add

Now that tag_8021q has its own ops structure, it no longer relies on
dsa_port_vid_add, and therefore on the dsa_switch_ops to install its
VLANs.

So dsa_port_vid_add now only has one single caller. So we can simplify
the call graph to what it was before, aka:

        dsa_slave_vlan_rx_add_vid     dsa_slave_port_obj_add
                      |                         |
                      +-------+         +-------+
                              |         |
                              v         v
                           dsa_port_vlan_add
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

While working on another tag_8021q driver implementation, some things
became apparent:

- It is not mandatory for a DSA driver to offload the tag_8021q VLANs by
  using the VLAN table per se. For example, it can add custom TCAM rules
  that simply encapsulate RX traffic, and redirect & decapsulate rules
  for TX traffic. For such a driver, it makes no sense to receive the
  tag_8021q configuration through the same callback as it receives the
  VLAN configuration from the bridge and the 8021q modules.

- Currently, sja1105 (the only tag_8021q user) sets a
  priv->expect_dsa_8021q variable to distinguish between the bridge
  calling, and tag_8021q calling. That can be improved, to say the
  least.

- The crosschip bridging operations are, in fact, stateful already. The
  list of crosschip_links must be kept by the caller and passed to the
  relevant tag_8021q functions.

So it would be nice if the tag_8021q configuration was more
self-contained. This patch attempts to do that.

Create a struct dsa_8021q_context which encapsulates a struct
dsa_switch, and has 2 function pointers for adding and deleting a VLAN.
These will replace the previous channel to the driver, which was through
the .port_vlan_add and .port_vlan_del callbacks of dsa_switch_ops.

Also put the list of crosschip_links into this dsa_8021q_context.
Drivers that don't support cross-chip bridging can simply omit to
initialize this list, as long as they dont call any cross-chip function.

The sja1105_vlan_add and sja1105_vlan_del functions are refactored into
a smaller sja1105_vlan_add_one, which now has 2 entry points:
- sja1105_vlan_add, from struct dsa_switch_ops
- sja1105_dsa_8021q_vlan_add, from the tag_8021q ops
But even this change is fairly trivial. It just reflects the fact that
for sja1105, the VLANs from these 2 channels end up in the same hardware
table. However that is not necessarily true in the general sense (and
that's the reason for making this change).

The rest of the patch is mostly plain refactoring of "ds" -> "ctx". The
dsa_8021q_context structure needs to be propagated because adding a VLAN
is now done through the ops function pointers inside of it.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

There is no point in calling dsa_port_setup_8021q_tagging for each
individual port. Additionally, it will become more difficult to do that
when we'll have a context structure to tag_8021q (next patch). So
refactor this now.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The previous assumption was that the caller would already have this
header file included.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch moves complete nic tls offload (kTLS) code from crypto
directory to drivers/net/ethernet/chelsio/inline_crypto/ch_ktls
directory. nic TLS is made a separate ULD of cxgb4.
Signed-off-by: Rohit Maheshwari <rohitm@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Edward Cree says:

====================
sfc: encap offloads on EF10

EF10 NICs from the 8000 series onwards support TX offloads (checksumming,
 TSO) on VXLAN- and NVGRE-encapsulated packets.  This series adds driver
 support for these offloads.

Changes from v1:
 * Fix 'no TXQ of type' error handling in patch #1 (and clear up the
   misleading comment that inspired the wrong version)
 * Add comment in patch #5 explaining what the deal with TSOv3 is
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Necessitates an .ndo_features_check, as the EF10 datapath has several
 limitations on what it can handle.
Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

>From the 8000 series onwards, EF10 NICs with suitable firmware are able
 to perform TSO within VXLAN or NVGRE encapsulation.
Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Remove the tx_queue->handle_tso function pointer, and just use
 tx_queue->tso_version to decide which function to call, thus removing
 an indirect call from the fast path.
Instead of passing a tso_v2 flag to efx_mcdi_tx_init(), set the desired
 tx_queue->tso_version before calling it.
In efx_mcdi_tx_init(), report back failure to obtain a TSOv2 context by
 setting tx_queue->tso_version to 0, which will cause the TX path to
 use the GSO-based fallback.
Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Won't actually be exercised until we start advertising the corresponding
 offload features.
Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

If the MC reports the VXLAN_NVGRE datapath capability, then these queues
 can be used for checksum offload of encapsulated packets.
Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Nothing yet creates inner csum TXQs; just change all references to
 EFX_TXQ_TYPE_OFFLOAD to the new EFX_TXQ_TYPE_OUTER_CSUM.
Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Make it possible to have an arbitrary mapping from types to labels,
 because when we add inner-csum-offload TXQs there will no longer be a
 convenient nesting hierarchy of NIC types (EF10 will have inner-csum
 TXQs, while Siena will have HIGHPRI).
Correct a misleading comment on efx_hard_start_xmit().
Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

These are never modified, so constify them to allow the compiler to
place them in read-only memory. This moves about 25kB to read-only
memory as seen by the output of the size command.

Before:
   text    data     bss     dec     hex filename
 296203   65464    1248  362915   589a3 drivers/net/ethernet/marvell/octeontx2/af/octeontx2_af.ko

After:
   text    data     bss     dec     hex filename
 321003   40664    1248  362915   589a3 drivers/net/ethernet/marvell/octeontx2/af/octeontx2_af.ko
Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Edward Cree says:

====================
sfc: misc cleanups

Clean up a few nits I noticed while working on TXQ stuff.
====================
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

The old_channel argument is never used, so remove it.
The function is only called from elsewhere in efx_channels.c, so make
 it static and remove the declaration from the header file.
Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The statement above it already returns, so there is no way to get here.
Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

efx_init_struct already calls this, we don't need to do it again.
Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Each MDB entry is encoded in a nested netlink attribute called
'MDBA_MDB_ENTRY'. In turn, this attribute contains another nested
attributed called 'MDBA_MDB_ENTRY_INFO', which encodes a single port
group entry within the MDB entry.

The cited commit added the ability to restart a dump from a specific
port group entry. However, on failure to add a port group entry to the
dump the entire MDB entry (stored in 'nest2') is removed, resulting in
missing port group entries.

Fix this by finalizing the MDB entry with the partial list of already
encoded port group entries.

Fixes: 5205e919 ("net: bridge: mcast: add support for src list and filter mode dumping")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The variable err is being initialized with a value that is never read and
it is being updated later with a new value. The initialization is redundant
and can be removed.  Also re-order variable declarations in reverse
Christmas tree ordering.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Oleksij Rempel says:

====================
ag71xx: add ethtool and flow control support

The main target of this patches is to provide flow control support
for ag71xx driver. To be able to validate this functionality, I also
added ethtool support with HW counters. So, this patches was validated
with iperf3 and counters showing Pause frames send or received by this
NIC.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Add flow control support. The functionality was tested on AR9331 SoC and
confirmed by iperf3 results and HW counters exported over ethtool.
Following test configurations was used:

iMX6S receiver <--- TL-SG1005D switch <---- AR9331 sender

The switch is supporting symmytric flow control:
Settings for eth0:
        Supported ports: [ MII ]
        Supported link modes:   10baseT/Half 10baseT/Full
                                100baseT/Half 100baseT/Full
        Supported pause frame use: Symmetric Receive-only
        Supports auto-negotiation: Yes
        Supported FEC modes: Not reported
        Advertised link modes:  10baseT/Half 10baseT/Full
                                100baseT/Half 100baseT/Full
        Advertised pause frame use: Symmetric
        Advertised auto-negotiation: Yes
        Advertised FEC modes: Not reported
        Link partner advertised link modes:  10baseT/Half 10baseT/Full
                                             100baseT/Half 100baseT/Full
--->>   Link partner advertised pause frame use: Symmetric
        Link partner advertised auto-negotiation: Yes
        Link partner advertised FEC modes: Not reported
        Speed: 100Mb/s
        Duplex: Full
        Auto-negotiation: on
        Port: MII
        PHYAD: 4
        Transceiver: external
        Link detected: yes

The iMX6S system was configured to 10Mbit, to let the switch use flow
control:
  - ethtool -s eth0 speed 10

With flow control disabled on AR9331:
  - ethtool -A eth0  rx off tx off
  - iperf3 -u -c 172.17.0.1 -b100M -l1472 -t10

[ ID] Interval           Transfer     Bitrate         Jitter    Lost/Total Datagrams
[  5]   0.00-10.00  sec  66.2 MBytes  55.5 Mbits/sec  0.000 ms  0/47155 (0%)  sender
[  5]   0.00-10.04  sec  11.5 MBytes  9.57 Mbits/sec  1.309 ms  38986/47146 (83%)  receiver

With flow control enabled on AR9331:
  - ethtool -A eth0  rx on tx on
  - iperf3 -u -c 172.17.0.1 -b100M -l1472 -t10

[ ID] Interval           Transfer     Bitrate         Jitter    Lost/Total Datagrams
[  5]   0.00-10.00  sec  15.1 MBytes  12.6 Mbits/sec  0.000 ms  0/10727 (0%)  sender
[  5]   0.00-10.05  sec  11.5 MBytes  9.57 Mbits/sec  1.371 ms  2525/10689 (24%)  receiver

Similar results are get in opposite direction by introducing extra CPU
load on AR9331:
  - chrt 40 dd if=/dev/zero of=/dev/null &
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>