Still can't use spi clock over 12MHz (5.4 kernel)
We applied lowlatency to the 5.4 kernel and tested spi.
It was confirmed that the time from the point where the CS pin becomes low to the point where the clock starts is longer than before. (0.42us --> 14us)
However, if the clock is still set to 12MHz or higher, the clock stops in the middle just like the 5.0 kernel.
Please note that I have inquired about this problem before.