> > I was not asking anyone to reproduce my exact setup. > > I find it confusing that some assume there is something different > about the board I'm using. The more likely hypothesis is that all > S905X2 boards have the same behavior. High-speed MMC modes are usually defined/limited per boards. Check the different DTs in arch/arm64/boot/dts/amlogic, you'll see that not all have the same configs. Yes the S905X2 has the bounce buffer work-around which plays a role on the overall performance. MMC high-speed modes is critical just has well. The Amlogic 4.9 downstream does all kinds of fancy (and unsafe) things to enable higher modes. So there is no assumption here, merely a tentative to get a clearer picture. > > Regards