e124bab08a
[ Upstream commit e780e3193e889fd8358b862f7cd18ec5a4901caf ]
Rather than reading the stats64 counters directly from the 32-bit
hardware, it's better to rely on the output produced by the periodic
ocelot_port_update_stats().
It would be even better to call ocelot_port_update_stats() right from
ocelot_get_stats64() to make sure we report the current values rather
than the ones from 2 seconds ago. But we need to export
ocelot_port_update_stats() from the switch lib towards the switchdev
driver for that, and future work will largely undo that.
There are more ocelot-based drivers waiting to be introduced, an example
of which is the SPI-controlled VSC7512. In that driver's case, it will
be impossible to call ocelot_port_update_stats() from ndo_get_stats64
context, since the latter is atomic, and reading the stats over SPI is
sleepable. So the compromise taken here, which will also hold going
forward, is to report 64-bit counters to stats64, which are not 100% up
to date.
Fixes: a556c76adc05 ("net: mscc: Add initial Ocelot switch support")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.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.