Re: [PATCH v3 05/10] Documentation: PM: amd-pstate: add debugging section for driver loading failure

From: Mario Limonciello
Date: Tue Jun 11 2024 - 15:07:14 EST


On 6/11/2024 03:52, 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 loglevel=4 debug
amd_pstate=active" to the kernel command line, driver debug logging is enabled.

Here's some suggestion for text.

"
On some platforms if amd-pstate fails to load or operate properly users will need to turn on extra debugging messages.
"

However - I would argue that the messages are the wrong level if they need debugging messages turned on when it fails to load.

Something causing a failure to load should be pr_warn() or pr_notice()
IMO.


Signed-off-by: Perry Yuan <perry.yuan@xxxxxxx>
---
Documentation/admin-guide/pm/amd-pstate.rst | 13 +++++++++++++
1 file changed, 13 insertions(+)

diff --git a/Documentation/admin-guide/pm/amd-pstate.rst b/Documentation/admin-guide/pm/amd-pstate.rst
index 1e0d101b020a..de83e742738e 100644
--- a/Documentation/admin-guide/pm/amd-pstate.rst
+++ b/Documentation/admin-guide/pm/amd-pstate.rst
@@ -472,6 +472,19 @@ operations for the new ``amd-pstate`` module with this tool. ::
Diagnostics and Tuning
=======================
+Debugging AMD P-State Driver Loading Issues
+------------------------------------------
+
+On some platforms, there may be issues with the loading of the amd-pstate driver.

This makes it sound like it's by design. Of course it isn't by design, so I would instead say:

"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"
+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
--------------