For ENETC ports that register an external MDIO bus,
the bus doesn't get removed on the error bailout path
of enetc_pf_probe().

This issue became much more visible after recent:
commit 07095c02 ("net: enetc: Use DT protocol information to set up the ports")
Before this commit, one could make probing fail on the error
path only by having register_netdev() fail, which is unlikely.
But after this commit, because it moved the enetc_of_phy_get()
call up in the probing sequence, now we can trigger an mdiobus_free()
bug just by forcing enetc_alloc_msix() to return error, i.e. with the
'pci=nomsi' kernel bootarg (since ENETC relies on MSI support to work),
as the calltrace below shows:

kernel BUG at /home/eiz/work/enetc/net/drivers/net/phy/mdio_bus.c:648!
Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
[...]
Hardware name: LS1028A RDB Board (DT)
pstate: 80000005 (Nzcv daif -PAN -UAO BTYPE=--)
pc : mdiobus_free+0x50/0x58
lr : devm_mdiobus_free+0x14/0x20
[...]
Call trace:
 mdiobus_free+0x50/0x58
 devm_mdiobus_free+0x14/0x20
 release_nodes+0x138/0x228
 devres_release_all+0x38/0x60
 really_probe+0x1c8/0x368
 driver_probe_device+0x5c/0xc0
 device_driver_attach+0x74/0x80
 __driver_attach+0x8c/0xd8
 bus_for_each_dev+0x7c/0xd8
 driver_attach+0x24/0x30
 bus_add_driver+0x154/0x200
 driver_register+0x64/0x120
 __pci_register_driver+0x44/0x50
 enetc_pf_driver_init+0x24/0x30
 do_one_initcall+0x60/0x1c0
 kernel_init_freeable+0x1fc/0x274
 kernel_init+0x14/0x110
 ret_from_fork+0x10/0x34

Fixes: ebfcb23d ("enetc: Add ENETC PF level external MDIO support")
Signed-off-by: Claudiu Manoil <claudiu.manoil@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Currently drive supports taprio offload which is a tc feature offloaded
to cpsw hardware. So driver has to set the hw feature flag, NETIF_F_HW_TC
in the net device to be compliant. This patch adds the flag.

Fixes: 8127224c ("ethernet: ti: am65-cpsw-qos: add TAPRIO offload support")
Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When regmap_update_bits failed in ave_init(), calls of the functions
reset_control_assert() and clk_disable_unprepare() were missed.
Add goto out_reset_assert to do this.

Fixes: 57878f2f ("net: ethernet: ave: add support for phy-mode setting of system controller")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wang Hai <wanghai38@huawei.com>
Reviewed-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This driver is not working because of problems of its receiving code.
This patch fixes it to make it work.

When the driver receives an LAPB frame, it should first pass the frame
to the LAPB module to process. After processing, the LAPB module passes
the data (the packet) back to the driver, the driver should then add a
one-byte pseudo header and pass the data to upper layers.

The changes to the "x25_asy_bump" function and the
"x25_asy_data_indication" function are to correctly implement this
procedure.

Also, the "x25_asy_unesc" function ignores any frame that is shorter
than 3 bytes. However the shortest frames are 2-byte long. So we need
to change it to allow 2-byte frames to pass.

Cc: Eric Dumazet <edumazet@google.com>
Cc: Martin Schiller <ms@dev.tdt.de>
Signed-off-by: Xie He <xie.he.0141@gmail.com>
Reviewed-by: Martin Schiller <ms@dev.tdt.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

According to 'man 8 ip-netns', if `ip netns identify` returns an empty string,
there's no net namespace associated with current PID: fix the net ns entrance
logic.
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Alexander Lobakin says:

====================
qed: suppress irrelevant error messages on HW init

This raises the verbosity level of several error/warning messages on
driver/module initialization, most of which are false-positives, and
the one actively spamming the log for no reason.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

It was found that qed_pglueb_rbc_attn_handler() can produce a lot of
false-positive error detections on driver load/reload (especially after
crashes/recoveries) and spam the kernel log:

[    4.958275] [qed_pglueb_rbc_attn_handler:324()]ICPL error - 00d00ff0
[ 2079.146764] [qed_pglueb_rbc_attn_handler:324()]ICPL error - 00d80ff0
[ 2116.374631] [qed_pglueb_rbc_attn_handler:324()]ICPL error - 00d80ff0
[ 2135.250564] [qed_pglueb_rbc_attn_handler:324()]ICPL error - 00d80ff0
[...]

Reduce the logging level of two false-positive prone error messages from
notice to verbose on initialization (only) to not mix it with real error
attentions while debugging.

Fixes: 666db486 ("qed: Revise load sequence to avoid PCI errors")
Signed-off-by: Alexander Lobakin <alobakin@marvell.com>
Signed-off-by: Igor Russkikh <irusskikh@marvell.com>
Signed-off-by: Michal Kalderon <michal.kalderon@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Change the verbosity of the "don't support RoCE & iWARP simultaneously"
warning to debug level to stop flooding on driver/hardware initialization:

[    4.783230] qede 01:00.00: Storm FW 8.37.7.0, Management FW 8.52.9.0
[MBI 15.10.6] [eth0]
[    4.810020] [qed_rdma_set_pf_params:2076()]Current day drivers don't
support RoCE & iWARP simultaneously on the same PF. Default to RoCE-only
[    4.861186] qede 01:00.01: Storm FW 8.37.7.0, Management FW 8.52.9.0
[MBI 15.10.6] [eth1]
[    4.893311] [qed_rdma_set_pf_params:2076()]Current day drivers don't
support RoCE & iWARP simultaneously on the same PF. Default to RoCE-only
[    5.181713] qede a1:00.00: Storm FW 8.37.7.0, Management FW 8.52.9.0
[MBI 15.10.6] [eth2]
[    5.224740] [qed_rdma_set_pf_params:2076()]Current day drivers don't
support RoCE & iWARP simultaneously on the same PF. Default to RoCE-only
[    5.276449] qede a1:00.01: Storm FW 8.37.7.0, Management FW 8.52.9.0
[MBI 15.10.6] [eth3]
[    5.318671] [qed_rdma_set_pf_params:2076()]Current day drivers don't
support RoCE & iWARP simultaneously on the same PF. Default to RoCE-only
[    5.369548] qede a1:00.02: Storm FW 8.37.7.0, Management FW 8.52.9.0
[MBI 15.10.6] [eth4]
[    5.411645] [qed_rdma_set_pf_params:2076()]Current day drivers don't
support RoCE & iWARP simultaneously on the same PF. Default to RoCE-only

Fixes: e0a8f9de ("qed: Add iWARP enablement support")
Signed-off-by: Alexander Lobakin <alobakin@marvell.com>
Signed-off-by: Igor Russkikh <irusskikh@marvell.com>
Signed-off-by: Michal Kalderon <michal.kalderon@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In the nsim_create(), rtnl_lock() is called before nsim_bpf_init().
If nsim_bpf_init() is failed, rtnl_unlock() should be called,
but it isn't called.
So, unbalanced locking would occur.

Fixes: e05b2d14 ("netdevsim: move netdev creation/destruction to dev probe")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

When doing "ip link set dev ... up" for a ksz9477 backed link,
ksz9477_phy_setup is called and it calls phy_remove_link_mode to remove
1000baseT HDX. During phy_remove_link_mode, phy_advertise_supported is
called. Doing so reverts any previous change to advertised link modes
e.g. using a udevd .link file.

phy_remove_link_mode is not meant to be used while opening a link and
should be called during phy probe when the link is not yet available to
userspace.

Therefore move the phy_remove_link_mode calls into
ksz9477_switch_register. It indirectly calls dsa_register_switch, which
creates the relevant struct phy_devices and we update the link modes
right after that. At that time dev->features is already initialized by
ksz9477_switch_detect.

Remove phy_setup from ksz_dev_ops as no users remain.

Link: https://lore.kernel.org/netdev/20200715192722.GD1256692@lunn.ch/
Fixes: 42fc6a4c ("net: dsa: microchip: prepare PHY for proper advertisement")
Signed-off-by: Helmut Grohne <helmut.grohne@intenta.de>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Huazhong Tan says:

====================
net: hns3: fixes for -net

There are some bugfixes for the HNS3 ethernet driver.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Currently, PF queries the MAC link status per second by calling
function hclge_get_mac_link_status(). It return the error code
when failed to send cmdq command to firmware. It's incorrect,
because this return value is used as the MAC link status, which
0 means link down, and none-zero means link up. So fixes it.

Fixes: 46a3df9f ("net: hns3: Add HNS3 Acceleration Engine & Compatibility Layer Support")
Signed-off-by: Jian Shen <shenjian15@huawei.com>
Signed-off-by: Huazhong tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The content of the TX desc is automatically cleared by the HW
when the HW has sent out the packet to the wire. When desc filling
fails in hns3_nic_net_xmit(), it will call hns3_clear_desc() to do
the error handling, which miss zeroing of the TX desc and the
checking if a unmapping is needed.

So add the zeroing and checking in hns3_clear_desc() to avoid the
above problem. Also add DESC_TYPE_UNKNOWN to indicate the info in
desc_cb is not valid, because hns3_nic_reclaim_desc() may treat
the desc_cb->type of zero as packet and add to the sent pkt
statistics accordingly.

Fixes: 76ad4f0e ("net: hns3: Add support of HNS3 Ethernet Driver for hip08 SoC")
Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

With GRO and fraglist support, the SKB can be aggregated to
a total size of 65535, and when that SKB is forwarded through
a bridge, the size of the SKB may be pushed to exceed the size
of 65535 when br_dev_queue_push_xmit() is called.

The max send size of BD supported by the HW is 65535, when a SKB
with a headlen of over 65535 is sent to the driver, the driver
needs to use multi BD to send the linear data, and the send size
of the last BD is calculated incorrectly by the driver who is
using '&' operation, which causes a TX error.

Use '%' operation to fix this problem.

Fixes: 3fe13ed9 ("net: hns3: avoid mult + div op in critical data path")
Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When a big TX buffer is sent using multi BD, the driver maps the
whole TX buffer, and unmaps it using info in desc_cb corresponding
to each BD, but only the info in the desc_cb of first BD is correct,
other info in desc_cb is wrong, which causes TX unmapping problem
when SMMU is on.

Only set the mapping and freeing info in the desc_cb of first BD to
fix this problem, because the TX buffer only need to be unmapped and
freed once.

Fixes: 1e8a7977("net: hns3: add handling for big TX fragment")
Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: Huzhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

We can't use IS_UDPLITE to replace udp_sk->pcflag when UDPLITE_RECV_CC is
checked.

Fixes: b2bf1e26 ("[UDP]: Clean up for IS_UDPLITE macro")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When I cat 'tx_timeout' by sysfs, it displays as follows. It's better to
add a newline for easy reading.

root@syzkaller:~# cat /sys/devices/virtual/net/lo/queues/tx-0/tx_timeout
0root@syzkaller:~#
Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

According to the report of [1], this driver is possible to cause
the following error in ravb_tx_timeout_work().

ravb e6800000.ethernet ethernet: failed to switch device to config mode

This error means that the hardware could not change the state
from "Operation" to "Configuration" while some tx and/or rx queue
are operating. After that, ravb_config() in ravb_dmac_init() will fail,
and then any descriptors will be not allocaled anymore so that NULL
pointer dereference happens after that on ravb_start_xmit().

To fix the issue, the ravb_tx_timeout_work() should check
the return values of ravb_stop_dma() and ravb_dmac_init().
If ravb_stop_dma() fails, ravb_tx_timeout_work() re-enables TX and RX
and just exits. If ravb_dmac_init() fails, just exits.

[1]
https://lore.kernel.org/linux-renesas-soc/20200518045452.2390-1-dirk.behme@de.bosch.com/Reported-by: Dirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Sergei Shtylyov <sergei.shtylyov@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Kuniyuki Iwashima says:

====================
udp: Fix reuseport selection with connected sockets.

This patch set addresses two issues which happen when both connected and
unconnected sockets are in the same UDP reuseport group.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Currently, SO_REUSEPORT does not work well if connected sockets are in a
UDP reuseport group.

Then reuseport_has_conns() returns true and the result of
reuseport_select_sock() is discarded. Also, unconnected sockets have the
same score, hence only does the first unconnected socket in udp_hslot
always receive all packets sent to unconnected sockets.

So, the result of reuseport_select_sock() should be used for load
balancing.

The noteworthy point is that the unconnected sockets placed after
connected sockets in sock_reuseport.socks will receive more packets than
others because of the algorithm in reuseport_select_sock().

    index | connected | reciprocal_scale | result
    ---------------------------------------------
    0     | no        | 20%              | 40%
    1     | no        | 20%              | 20%
    2     | yes       | 20%              | 0%
    3     | no        | 20%              | 40%
    4     | yes       | 20%              | 0%

If most of the sockets are connected, this can be a problem, but it still
works better than now.

Fixes: acdcecc6 ("udp: correct reuseport selection with connected sockets")
CC: Willem de Bruijn <willemb@google.com>
Reviewed-by: Benjamin Herrenschmidt <benh@amazon.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

If an unconnected socket in a UDP reuseport group connect()s, has_conns is
set to 1. Then, when a packet is received, udp[46]_lib_lookup2() scans all
sockets in udp_hslot looking for the connected socket with the highest
score.

However, when the number of sockets bound to the port exceeds max_socks,
reuseport_grow() resets has_conns to 0. It can cause udp[46]_lib_lookup2()
to return without scanning all sockets, resulting in that packets sent to
connected sockets may be distributed to unconnected sockets.

Therefore, reuseport_grow() should copy has_conns.

Fixes: acdcecc6 ("udp: correct reuseport selection with connected sockets")
CC: Willem de Bruijn <willemb@google.com>
Reviewed-by: Benjamin Herrenschmidt <benh@amazon.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Commit 02288248 ("tipc: eliminate gap indicator from ACK messages")
eliminated sending of the 'gap' indicator in regular ACK messages and
only allowed to build NACK message with enabled probe/probe_reply.
However, necessary correction for building NACK message was missed
in tipc_link_timeout() function. This leads to significant delay and
link reset (due to retransmission failure) in lossy environment.

This commit fixes it by setting the 'probe' flag to 'true' when
the receive deferred queue is not empty. As a result, NACK message
will be built to send back to another peer.

Fixes: 02288248 ("tipc: eliminate gap indicator from ACK messages")
Acked-by: Jon Maloy <jmaloy@redhat.com>
Signed-off-by: Tung Nguyen <tung.q.nguyen@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix the warning: [-Werror=-Wframe-larger-than=]

drivers/net/ethernet/neterion/vxge/vxge-main.c:
In function'VXGE_COMPLETE_VPATH_TX.isra.37':
drivers/net/ethernet/neterion/vxge/vxge-main.c:119:1:
warning: the frame size of 1056 bytes is larger than 1024 bytes

Dropping the NR_SKB_COMPLETED to 16 is appropriate that won't
have much impact on performance and functionality.
Signed-off-by: Bixuan Cui <cuibixuan@huawei.com>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

The ag71xx_mdio_probe() forgets to call clk_disable_unprepare() when
of_reset_control_get_exclusive() failed. Add the missed call to fix it.

Fixes: d51b6ce4 ("net: ethernet: add ag71xx driver")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Huang Guobin <huangguobin4@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The fragment packets do defrag in tcf_ct_handle_fragments
will clear the skb->cb which make the qdisc_skb_cb clear
too. So the qdsic_skb_cb should be store before defrag and
restore after that.
It also update the pkt_len after all the
fragments finish the defrag to one packet and make the
following actions counter correct.

Fixes: b57dc7c1 ("net/sched: Introduce action ct")
Signed-off-by: wenxu <wenxu@ucloud.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>

The implementation of s3fwrn5_recv_frame() is supposed to consume skb on
all execution paths. Release skb before returning -ENODEV.
Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ip_dev_find() call holds net_device reference which is not needed,
use __ip_dev_find() which does not hold reference.

v1->v2:
- Correct submission tree.
- Add fixes tag.

Fixes: cc35c88a ("crypto : chtls - CPL handler definition")
Signed-off-by: Vinay Kumar Yadav <vinay.yadav@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When tls data skb is pending for Tx and tls alert comes , It
is wrongly overwrite the record type of tls data to tls alert
record type. fix the issue correcting it.

v1->v2:
- Correct submission tree.
- Add fixes tag.

Fixes: 6919a826 ("Crypto/chtls: add/delete TLS header in driver")
Signed-off-by: Vinay Kumar Yadav <vinay.yadav@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Shannon Nelson says:

====================
ionic: locking and filter fixes

These patches address an ethtool show regs problem, some locking sightings,
and issues with RSS hash and filter_id tracking after a managed FW update.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

The ionic_wait_on_bit_lock() was a open-coded mutex knock-off
used only for protecting the queue reset operations, and there
was no reason not to use the real thing.  We can use the lock
more correctly and to better protect the queue stop and start
operations from cross threading.  We can also remove a useless
and expensive bit operation from the Rx path.

This fixes a case found where the link_status_check from a link
flap could run into an MTU change and cause a crash.

Fixes: beead698 ("ionic: Add the basic NDO callbacks for netdev support")
Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

Make sure the RSS hash key is kept across a fw update by not
de-initing it when an update is happening.

Fixes: c672412f ("ionic: remove lifs on fw reset")
Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

When we replay the rx filters after a fw-upgrade we get new
filter_id values from the FW, which we need to save and update
in our local filter list.  This allows us to delete the filters
with the correct filter_id when we're done.

Fixes: 7e4d4759 ("ionic: replay filters after fw upgrade")
Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add in a couple of forgotten spinlocks and fix up some of
the debug messages around filter management.

Fixes: c1e329eb ("ionic: Add management of rx filters")
Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use an offset to write the second half of the regs data into the
second half of the buffer instead of overwriting the first half.

Fixes: 4d03e00a ("ionic: Add initial ethtool support")
Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

skb_put_padto() can fail. So check for return type and return NULL
for skb. Caller checks for skb and acts correctly if it is NULL.

Fixes: 6d6148bc ("net: hsr: fix incorrect lsdu size in the tag of HSR frames for small frames")
Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

bareudp.rst was written before iproute2 gained support for this new
type of tunnel. Therefore, the sample command lines didn't match the
final iproute2 implementation.
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When mlxsw_core_trap_register fails in mlxsw_emad_init,
destroy_workqueue() shouled be called to destroy mlxsw_core->emad_wq.

Fixes: d965465b ("mlxsw: core: Fix possible deadlock")
Signed-off-by: Liu Jian <liujian56@huawei.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When dma_coerce_mask_and_coherent() fails, the alloced netdev need to be freed.

Fixes: 060ad66f ("dpaa_eth: change DMA device")
Signed-off-by: Liu Jian <liujian56@huawei.com>
Acked-by: Madalin Bucur <madalin.bucur@oss.nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Karsten Graul says:

====================
net/smc: fixes 2020-07-20

Please apply the following patch series for smc to netdev's net tree.

Patch 1 fixes a problem with a buffer that is not put back when the
connection was killed in the meantime.
Patch 2 fixes a wrong behaviour when the maximum dmb buffer count
exceeded.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

There is a current limit of 1920 registered dmb buffers per ISM device
for smc-d. One link group can contain 255 connections, each connection
is using one dmb buffer. When the connection is closed then the
registered buffer is held in a queue and is reused by the next
connection. When a link group is 'full' then another link group is
created and uses an own buffer pool. The link groups are added to a
list using list_add() which puts a new link group to the first position
in the list.
In the situation that many connections are opened (>1920) and a few of
them stay open while others are closed quickly we end up with at least 8
link groups. For a new connection a matching link group is looked up,
iterating over the list of link groups. The trailing 7 link groups
all have registered dmb buffers which could be reused, while the first
link group has only a few dmb buffers and then hit the 1920 limit.
Because the first link group is not full (255 connection limit not
reached) it is chosen and finally the connection falls back to TCP
because there is no dmb buffer available in this link group.
There are multiple ways to fix that: using list_add_tail() allows
to scan older link groups first for free buffers which ensures that
buffers are reused first. This fixes the problem for smc-r link groups
as well. For smc-d there is an even better way to address this problem
because smc-d does not have the 255 connections per link group limit.
So fix the problem for smc-d by allowing large link groups.

Fixes: c6ba7c9b ("net/smc: add base infrastructure for SMC-D and ISM")
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>