phy: qcom-qmp-pcie: replace power-down delay
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.orgSigned-off-by:
Vinod Koul <vkoul@kernel.org>
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