51bd33069f
The power-down delay was included in the first version of the QMP driver as an optional delay after powering on the PHY (using POWER_DOWN_CONTROL) and just before starting it. Later changes modified this sequence by powering on before initialising the PHY, but the optional delay stayed where it was (i.e. before starting the PHY). The vendor driver does not use a delay before starting the PHY and this is likely not needed on any platform unless there is a corresponding delay in the vendor kernel init sequence tables (i.e. in devicetree). But as the vendor kernel do have a 1 ms delay *after* starting the PHY and before starting to poll the status it is possible that later contributors have simply not noticed that the mainline power-down delay is not equivalent. As the current delay before even starting the PHY is pretty much pointless and likely a mistake, move the delay after starting the PHY which avoids a few iterations of polling and speeds up startup by 1 ms (the poll loop otherwise takes about 1.8 ms). Note that MSM8998 has never used a power-down delay so add a flag to skip the delay in case starting the PHY is faster on MSM8998. This can be removed after someone takes a measurement. Signed-off-by: Johan Hovold <johan+linaro@kernel.org> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Link: https://lore.kernel.org/r/20221012081241.18273-10-johan+linaro@kernel.org Signed-off-by: Vinod Koul <vkoul@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.