we are using a custom board base i.MX6D,kernel version:3.0.15.
I use U disk to update system,when I plug in U disk that with update packages,it start to update.
before updating finish,plug it out.When I test this procedure many times,i.MX6D can't enumerate USB devices at the end.
I upload four attachments:
Line 1:I plug a U disk in,after 2 seconds, I plug it out;
Line 10:After 33 seconds USB disconnect;I can't not understand why it disconnect more than 33 seconds,then error occured.
Line 34:I plug this U disk again,but it can't be enumerated.
When error occured,I read EHCI and USB PHY register's value.
This is hardware schematic about this USB port.D+ and D- directly connected to USB_HOST_DP and USB_HOST_DN in i.MX6D.
I had try this work:
1. Capture USB D+ and D- waveform,nothing different happened when plug U disk out.
2. I try to change USBPHYx_TXn register D_CAL's value,but error still happened.
3. When error occured,i.MX6 can't enumerate all USB devices include low speed.
Thanks & Regards