Logo of The Linux Kernel

The Linux Kernel

next-20251107

Quick search

Contents

  • Development process
  • Submitting patches
  • Code of conduct
  • Maintainer handbook
  • All development-process docs
  • Core API
  • Driver APIs
  • Subsystems
    • Core subsystems
    • Human interfaces
    • Networking interfaces
      • Networking
      • NetLabel
      • InfiniBand
      • ISDN
      • MHI
    • Storage interfaces
    • Other subsystems
  • Locking
  • Licensing rules
  • Writing documentation
  • Development tools
  • Testing guide
  • Hacking guide
  • Tracing
  • Fault injection
  • Livepatching
  • Rust
  • Administration
  • Build system
  • Reporting issues
  • Userspace tools
  • Userspace API
  • Firmware
  • Firmware and Devicetree
  • CPU architectures
  • Unsorted documentation
  • Translations

This Page

  • Show Source

stmmac (synopsys dwmac) devlink support¶

This document describes the devlink features implemented by the stmmac device driver.

Parameters¶

The stmmac driver implements the following driver-specific parameters.

Driver-specific parameters implemented¶

Name

Type

Mode

Description

phc_coarse_adj

Boolean

runtime

Enable the Coarse timestamping mode, as defined in the DWMAC TRM. A detailed explanation of this timestamping mode can be found in the Socfpga Functionnal Description [1].

In Coarse mode, the ptp clock is expected to be fed by a high-precision clock that is externally adjusted, and the subsecond increment used for timestamping is set to 1/ptp_clock_rate.

In Fine mode (i.e. Coarse mode == false), the ptp clock frequency is continuously adjusted, but the subsecond increment is set to 2/ptp_clock_rate.

Coarse mode is suitable for PTP Grand Master operation. If unsure, leave the parameter to False.

[1] https://www.intel.com/content/www/us/en/docs/programmable/683126/21-2/functional-description-of-the-emac.html

©The kernel development community. | Powered by Sphinx 7.4.7 & Alabaster 0.7.16 | Page source