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

From: Mario Limonciello
Date: Tue Jun 18 2024 - 15:25:14 EST


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@xxxxxxx>
---
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
--------------