0bf3672946
[ Upstream commit acdbf5f9b2c492505145f6e50c65418521a547c4 ]
This driver relies on SMEM to populate items for each subsystem before
the device probes. The items in SMEM that are being looked for are
populated by the subsystems lazily, and therefore may not exist until
the device has booted. For example, if I build this driver into the
kernel on Trogdor Lazor and boot up, I don't see a 'modem' debugfs file
populated, because the modem boots and populates the SMEM item after
this driver probes.
Always populate the files for the subsystems if they're in SMEM, and
make the qcom_subsystem_sleep_stats_show() function return 0 if the SMEM
items still isn't there. This way we can run a simple command like
grep ^ /sys/kernel/debug/qcom_stats/*
and collect the subsystem sleep stats without interspersed errors or
missing details entirely because this driver probed first.
Fixes: 1d7724690344 ("soc: qcom: Add Sleep stats driver")
Cc: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230119032329.2909383-1-swboyd@chromium.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
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 Restructured Text 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.