The SD and eMMC controller has become terribly slow in 2018.3: # echo 3 > /proc/sys/vm/drop_caches
# dd if=/dev/mmcblk0 of=/dev/null bs=1M count=20 20+0 records in 20+0 records out 20971520 bytes (20.0MB) copied, 4.972666 seconds, 4.0MB/s # dd if=/dev/mmcblk1 of=/dev/null bs=1M count=20 20+0 records in 20+0 records out 20971520 bytes (20.0MB) copied, 38.899436 seconds, 526.5KB/s This used to be over 160MB/s for the eMMC (mmcblk0) and over 20 MB/s for the SD card (mmcblk0) with the 2018.1 kernel and bootloader. This is only in Linux, the bootloader still reads at about 10MB/s from the SD card. So apparently the clocks are set up okay. According to the kernel, the clocks and interface are running at full speed: # cat /sys/kernel/debug/mmc0/ios clock: 200000000 Hz actual clock: 200000000 Hz vdd: 21 (3.3 ~ 3.4 V) bus mode: 2 (push-pull) chip select: 0 (don't care) power mode: 2 (on) bus width: 3 (8 bits) timing spec: 9 (mmc HS200) signal voltage: 1 (1.80 V) driver type: 0 (driver type B) # cat /sys/kernel/debug/mmc1/ios clock: 50000000 Hz actual clock: 50000000 Hz vdd: 21 (3.3 ~ 3.4 V) bus mode: 2 (push-pull) chip select: 0 (don't care) power mode: 2 (on) bus width: 2 (4 bits) timing spec: 2 (sd high-speed) signal voltage: 0 (3.30 V) driver type: 0 (driver type B) Any insights? -- _______________________________________________ meta-xilinx mailing list [email protected] https://lists.yoctoproject.org/listinfo/meta-xilinx
