Am Dienstag, 20. Oktober 2015, 16:33:53 schrieb Douglas Anderson: > The comment for ahbcfg for rk3066 parameters (also used for rk3288) > claimed that ahbcfg was INCR16, but it wasn't. Since the bits weren't > shifted properly, the 0x7 ended up being masked and we ended up > programming 0x3 for the HBstLen. Let's set it to INCR16 properly. > > As per Wu Liang Feng at Rockchip this may increase transmission > efficiency. I did blackbox tests with writing 0s to a USB-based SD > reader (forcefully capping CPU Freq to try to measure efficiency): > cd /sys/devices/system/cpu/cpu0/cpufreq > echo userspace > scaling_governor > echo 126000 > scaling_setspeed > for i in $(seq 10); do > dd if=/dev/zero of=/dev/sdb bs=1M count=750 > done > > With the above tests I found that speeds went from ~15MB/s to ~18MB/s. > Note that most other tests I did (including reading from the same USB > reader) didn't show any difference in performance. > > Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx> I gave this a spin on a rk3288-firefly, runs fine and doesn't have any negative effects, so Tested-by: Heiko Stuebner <heiko@xxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
