Re: [PATCH v4 05/11] Documentation: PM: amd-pstate: add debugging section for driver loading failure

Mario Limonciello
2024-06-18T19:25:03Z

On 6/17/2024 01:59, Perry Yuan wrote:
> To address issues with the loading of the amd-pstate driver on certain platforms,
> It needs to enable dynamic debugging to capture debug messages during the driver
> loading process. By adding "amd_pstate.dyndbg=+p cppc_acpi.dyndbg=+p debug
> amd_pstate=active" and loglevel to the kernel command line, then driver debug
> logging is enabled.
>
> Signed-off-by: Perry Yuan <perry.yuan@amd.com>
> ---
> Documentation/admin-guide/pm/amd-pstate.rst | 14 ++++++++++++++
> 1 file changed, 14 insertions(+)
>
> diff --git a/Documentation/admin-guide/pm/amd-pstate.rst b/Documentation/admin-guide/pm/amd-pstate.rst
> index 1e0d101b020a..ceeb073c9ada 100644
> --- a/Documentation/admin-guide/pm/amd-pstate.rst
> +++ b/Documentation/admin-guide/pm/amd-pstate.rst
> @@ -472,6 +472,20 @@ operations for the new ``amd-pstate`` module with this tool. ::
> Diagnostics and Tuning
> =======================
>
> +Debugging AMD P-State Driver Loading Issues
> +------------------------------------------
> +
> +If the amd-pstate driver fails to load, additional debug information
> +may be necessary.
> +To capture debug messages for issue analysis, users can add below parameter,
> +"amd_pstate.dyndbg=+p cppc_acpi.dyndbg=+p debug"

What keys off "debug"? I would expect that dynamic debugging for the
first two is sufficient.

That being said; isn't everything important shown as a warning now with
this series?

Is this patch still needed?

> +to the kernel command line. This will enable dynamic debugging and allow better
> +analysis and troubleshooting of the driver loading process.
> +
> +Please note that adding this parameter will only enable debug logging during the
> +driver loading phase and may affect system behavior. Use this option with caution
> +and only for debugging purposes.
> +
> Trace Events
> --------------
>