[RFC PATCH 0/6] spi: Add OSPI PHY calibration support for spi-cadence-quadspi

[Michael Walle]

Am 2021-03-12 11:10, schrieb Pratyush Yadav:
> There is usually a delay from when the flash drives the data line (IOW,
> puts a data bit on it) and when the signal reaches the controller. This
> delay can vary by the flash, board, silicon characteristics,
> temperature, etc.

Temperature might change over time, but the calibration is only done
once. I don't know how much influence the temperature actually has, but
our boards are usually operating from -40°C to +85°C. So there might be
a possible temperature difference of 125K between actual calibration and
when the flash is accessed.

-michael