Hi! I have the same problem as: http://lists.infradead.org/pipermail/linux-arm-kernel/2012-March/091529.html Read/write speed of SDHC card is very slow. Kernel 2.6.35 works with a excellent mmc performance. Kernels from 3.17 to 4.9.5 works very slow with mmc. Is there any solutions about this problem?