2dc77993cb
AMD MP2 STB function provides a data buffer used to log debug information about the system execution during S2Idle suspend/resume. A data buffer known as the STB (Smart Trace Buffer) is a circular buffer which is a low-level log to assist in debugging by providing insights into any potential hangs or stalls that may occur during the S2Idle suspend/resume processes. The current PMC driver retrieves STB data from MP1, but there can be scenarios where MP1 might hang or become unresponsive, leading to the loss of critical data present in the STB buffer. This defeats the purpose of the STB buffer, which was originally meant to help identify system failures. This feature creates stb_read_previous_boot debugfs allows users to retrieve the STB log from MP2 specifically from the last occurrence of the S2Idle suspend/resume. A userspace daemon can access STB log of last S2Idle suspend/resume which can help to troubleshoot potential issues related to hangs or stalls during the S2Idle suspend/resume sequence. Reviewed-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com> Signed-off-by: Basavaraj Natikar <Basavaraj.Natikar@amd.com> Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Link: https://lore.kernel.org/r/20240404090702.325838-1-Basavaraj.Natikar@amd.com Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.