Welcome to the high speed usb issues club

I am also having unresolved problem with a custom H743 board trying to use ULPI at HS speed (480 Mb/s) for MSD (USB storage).
For now, I am able to have reliable OTG2 + ULPI + MSD, but ultimately, after host <-> device handshake, speed is reverted to FS, and I can confirm using dd that I am limited to 12Mb/s not 480Mb/s.
When running under debugger, I can see that in
Code: Select all
usb_lld_serve_interrupt
Code: Select all
((otgp->DSTS & DSTS_ENUMSPD_MASK) == DSTS_ENUMSPD_HS_480)
I am still investigating to determine if it's a hardware or software issue.
Alexandre