mlxbf_gige: increase MDIO polling rate

Bug #1974246 reported by David Thompson
6
This bug affects 1 person
Affects Status Importance Assigned to Milestone
linux-bluefield (Ubuntu)
Invalid
Undecided
Unassigned
Focal
Fix Released
Medium
David Thompson

Bug Description

SRU Justification:

[Impact]

There is MDIO logic within the mlxbf_gige driver that currently
polls for completed transactions every 100us. This has been
reviewed and tested in the lab and found to be inefficient.

[Fix]

The fix is to modify the driver logic to increase the MDIO
polling rate to 5us. With this change the amount of
time spent waiting for the MDIO BUSY signal to de-assert
drops from ~100us to ~27us for each operation.

[Test Case]

The driver should function as before, specifically:
* driver probes successfully
* oob_net0 link comes up, as seen with "ifconfig -a"
* reset and power cycle testing toggle PHY hardware,
  and oob_net0 link still comes up

[Regression Potential]

This change affects all MDIO transactions to the board-level
PHY device, and as such, could cause a regression with PHY
communications. However, this change has been heavily tested.

Stefan Bader (smb)
Changed in linux-bluefield (Ubuntu Focal):
assignee: nobody → David Thompson (dthompso-98)
importance: Undecided → Medium
status: New → In Progress
Changed in linux-bluefield (Ubuntu):
status: New → Invalid
Changed in linux-bluefield (Ubuntu Focal):
status: In Progress → Fix Committed
Revision history for this message
Ubuntu Kernel Bot (ubuntu-kernel-bot) wrote :

This bug is awaiting verification that the linux-bluefield/5.4.0-1037.40 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!

tags: added: verification-needed-focal
Revision history for this message
Launchpad Janitor (janitor) wrote :

This bug was fixed in the package linux-bluefield - 5.4.0-1040.44

---------------
linux-bluefield (5.4.0-1040.44) focal; urgency=medium

  * focal/linux-bluefield: 5.4.0-1040.44 -proposed tracker (LP: #1978639)

  * fix ref leak when switching zones (LP: #1979009)
    - net/sched: act_ct: fix ref leak when switching zones

  * Fix XFRM flags validity check (LP: #1978967)
    - SAUCE: net/xfrm: Fix XFRM flags validity check

  [ Ubuntu: 5.4.0-121.137 ]

  * focal/linux: 5.4.0-121.137 -proposed tracker (LP: #1978666)
  * Packaging resync (LP: #1786013)
    - debian/dkms-versions -- update from kernel-versions (main/2022.05.30)
  * CVE-2022-28388
    - can: usb_8dev: usb_8dev_start_xmit(): fix double dev_kfree_skb() in error
      path
  * test_vxlan_under_vrf.sh in net from ubuntu_kernel_selftests failed (Check VM
    connectivity through VXLAN (underlay in the default VRF) [FAIL])
    (LP: #1871015)
    - selftests: net: test_vxlan_under_vrf: fix HV connectivity test
  * [UBUNTU 20.04] CPU-MF: add extended counter set definitions for new IBM z16
    (LP: #1974433)
    - s390/cpumf: add new extended counter set for IBM z16
  * [UBUNTU 20.04] KVM nesting support leaks too much memory, might result in
    stalls during cleanup (LP: #1974017)
    - KVM: s390: vsie/gmap: reduce gmap_rmap overhead
  * [UBUNTU 20.04] Null Pointer issue in nfs code running Ubuntu on IBM Z
    (LP: #1968096)
    - NFS: Fix up nfs_ctx_key_to_expire()

  [ Ubuntu: 5.4.0-120.136 ]

  * CVE-2022-21123 // CVE-2022-21125 // CVE-2022-21166
    - cpu/speculation: Add prototype for cpu_show_srbds()
    - x86/cpu: Add Jasper Lake to Intel family
    - x86/cpu: Add Lakefield, Alder Lake and Rocket Lake models to the to Intel
      CPU family
    - x86/cpu: Add another Alder Lake CPU to the Intel family
    - Documentation: Add documentation for Processor MMIO Stale Data
    - x86/speculation/mmio: Enumerate Processor MMIO Stale Data bug
    - x86/speculation: Add a common function for MD_CLEAR mitigation update
    - x86/speculation/mmio: Add mitigation for Processor MMIO Stale Data
    - x86/bugs: Group MDS, TAA & Processor MMIO Stale Data mitigations
    - x86/speculation/mmio: Enable CPU Fill buffer clearing on idle
    - x86/speculation/mmio: Add sysfs reporting for Processor MMIO Stale Data
    - x86/speculation/srbds: Update SRBDS mitigation selection
    - x86/speculation/mmio: Reuse SRBDS mitigation for SBDS
    - KVM: x86/speculation: Disable Fill buffer clear within guests
    - x86/speculation/mmio: Print SMT warning

 -- Zachary Tahenakos <email address hidden> Tue, 21 Jun 2022 13:59:23 -0400

Changed in linux-bluefield (Ubuntu Focal):
status: Fix Committed → Fix Released
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