oob_net0 up but stops processing Rx packets

[David Thompson]

SRU Justification:

[Impact]
* The oob_net0 interface, managed by the mlxbf_gige driver, will be
  up and enabled but can stop processing received packets if three
  specific conditions occur:
  1) driver has received more than (N * RxRingSize) packets but less
     than (N+1 * RxRingSize) packets where N is an odd number.
     Note: the command "ethtool -g oob_net0" will display the current
     receive ring size, which currently defaults to 128.
  2) the driver's interface was disabled via "ifconfig oob_net0 down"
     during the window described in #1.
  3) the driver's interface is re-enabled via "ifconfig oob_net0 up"

  Without this fix, the driver needs to be unloaded and re-loaded
  to correct this condition.

[Fix]
* The fix is to ensure that the driver's "valid_polarity" field
  is cleared during the open() method so that it always matches
  the receive polarity used by hardware.

[Test Case]
* To test this fix, need to send in a specific number of packets to
  the "oob_net0" interface, then issue "ifconfig oob_net0 down" to
  disable the interface. A subsequent "ifconfig oob_net0 up" command
  will succesfully bring up the "oob_net0" interface and start the
  processing of received packets.

[Regression Potential]
* There is low risk of this fix causing any problems.

[Other]
* The mlxbf_gige driver will display v1.25 in modinfo after these changes.

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is awaiting verification that the linux-bluefield/5.4.0-1020.23 kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-focal' to 'verification-done-focal'. If the problem still exists, change the tag 'verification-needed-focal' to 'verification-failed-focal'.

If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[Kelsey Steele (kelsey-steele)]

Hi David, may you please verify this is resolved in the kernel sitting in proposed? You can find instructions for how to do this in comment #1. thank you!

[Meriton Tuli (meriton)]

Using 5.4.0-1020-bluefield, this Issue as been fixed:

# ifconfig oob_net0
oob_net0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet xxx.xxx.xxx.xxx netmask 255.255.255.0 broadcast 192.168.200.255
inet6 ---- prefixlen 64 scopeid 0x20<link>
ether XX:XX:XX:XX:XX:XX txqueuelen 1000 (Ethernet)
RX packets 136 bytes 11177 (11.1 KB)
RX errors 0 dropped 3 overruns 0 frame 0
TX packets 64 bytes 6526 (6.5 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

root@localhost:~# ifconfig oob_net0 down
root@localhost:~# ifconfig oob_net0 up

# ifconfig oob_net0
oob_net0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet xxx.xxx.xxx.xxx netmask 255.255.255.0 broadcast 192.168.200.255
inet6 ---- prefixlen 64 scopeid 0x20<link>
ether XX:XX:XX:XX:XX:XX txqueuelen 1000 (Ethernet)
RX packets 145 bytes 12281 (12.2 KB)
RX errors 0 dropped 3 overruns 0 frame 0
TX packets 75 bytes 8438 (8.4 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux-bluefield - 5.4.0-1020.23

---------------
linux-bluefield (5.4.0-1020.23) focal; urgency=medium

  * focal/linux-bluefield: 5.4.0-1020.23 -proposed tracker (LP: #1944877)

  * liburing stops working after upgrading to 5.4.0-1012 (LP: #1946219)
    - SAUCE: Revert "block: don't ignore REQ_NOWAIT for direct IO"

  * mlxbf_gige: update driver version to 1.25 (LP: #1943065)
    - SAUCE: mlxbf_gige: update driver version to 1.25

  * oob_net0 up but stops processing Rx packets (LP: #1942932)
    - SAUCE: mlxbf_gige: clear valid_polarity upon open

  * "ethtool -S oob_net0" does not report interrupt counts (LP: #1942931)
    - SAUCE: mlxbf_gige: add interrupt counts to "ethtool -S"

  [ Ubuntu: 5.4.0-89.100 ]

  * focal/linux: 5.4.0-89.100 -proposed tracker (LP: #1944901)
  * Packaging resync (LP: #1786013)
    - debian/dkms-versions -- update from kernel-versions (main/2021.09.27)
  * ext4 journal recovery fails w/ data=journal + mmap (LP: #1847340)
    - jbd2: introduce/export functions
      jbd2_journal_submit|finish_inode_data_buffers()
    - jbd2, ext4, ocfs2: introduce/use journal callbacks
      j_submit|finish_inode_data_buffers()
    - ext4: data=journal: fixes for ext4_page_mkwrite()
    - ext4: data=journal: write-protect pages on j_submit_inode_data_buffers()
    - ext4: fix mmap write protection for data=journal mode
  * CVE-2021-40490
    - ext4: fix race writing to an inline_data file while its xattrs are changing
  * Obsolete patch "UBUNTU: SAUCE: ext4: fix directory index node split
    corruption" (LP: #1942902)
    - Revert "UBUNTU: SAUCE: ext4: fix directory index node split corruption"
  * psock_snd.sh in net from ubuntu_kernel_selftests ADT failure with
    focal/groovy/hirsute/impish (LP: #1892213)
    - selftests/net: remove min gso test in packet_snd
  * Focal update: v5.4.143 upstream stable release (LP: #1944212)
    - ext4: fix EXT4_MAX_LOGICAL_BLOCK macro
    - x86/fpu: Make init_fpstate correct with optimized XSAVE
    - ath: Use safer key clearing with key cache entries
    - ath9k: Clear key cache explicitly on disabling hardware
    - ath: Export ath_hw_keysetmac()
    - ath: Modify ath_key_delete() to not need full key entry
    - ath9k: Postpone key cache entry deletion for TXQ frames reference it
    - mtd: cfi_cmdset_0002: fix crash when erasing/writing AMD cards
    - media: zr364xx: propagate errors from zr364xx_start_readpipe()
    - media: zr364xx: fix memory leaks in probe()
    - media: drivers/media/usb: fix memory leak in zr364xx_probe
    - USB: core: Avoid WARNings for 0-length descriptor requests
    - dmaengine: xilinx_dma: Fix read-after-free bug when terminating transfers
    - dmaengine: usb-dmac: Fix PM reference leak in usb_dmac_probe()
    - ARM: dts: am43x-epos-evm: Reduce i2c0 bus speed for tps65218
    - dmaengine: of-dma: router_xlate to return -EPROBE_DEFER if controller is not
      yet available
    - scsi: megaraid_mm: Fix end of loop tests for list_for_each_entry()
    - scsi: scsi_dh_rdac: Avoid crash during rdac_bus_attach()
    - scsi: core: Avoid printing an error if target_alloc() returns -ENXIO
    - scsi: core: Fix capacity set to zero a...