We've implement i.MX6 Dual plus/Quad plus and Yocto 1.8 .
USB port of HOST/OTG are unstable at both Dual plus and Quad plus .
If we try to do "time dd if=/dev/sda1 of=/dev/null bs=8k" , then sometimes show the message as below
==> "usb 1-1: reset high-speed USB device number 2 using ci_hdrc" .
==> "Buffer I/O error on device sda1"
==> "usb 1-1: device firmware changed"
So we've measure the USB signals and power , the report as attached file looks fine .
Also we try to reduce USB trace length (under 1200mils) , but still can't fix this issue .
(1) Does it have any power rail for internal USB logic , we need to double confirm ?
(2) Do you have any suggestion about USB Test item (EL_xx) we need to check , if we'll measure Hi-Speed USB signals again ?
(3) Does it have any register cause these wrong message ? Could we try to disable it ?
(4) Other recommend ?
Thanks a lot.