usbdebug: Adjust transaction retries

Transaction consistently completes with 80 to 150 status reads on my
setups. Hardware should always be able to complete this within 125us
as the debug port is serviced at the beginning of each microframe.

Timeout is set to DBGP_MICROFRAME_TIMEOUT_LOOPS=1000 status reads. Do not
retry transactions if this timeout is reached as the host controller
probably needs full re-initialisation to recover.

If this timeout is not reached, but a transaction is corrupted
on the wire, or it is otherwise not properly delivered to the USB device,
transaction is retried upto DBGP_MICROFRAME_RETRIES=10 times.

Change-Id: I44bc0a1bd194cdb5a2c13d5b81fc39bc568ae054
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/3881
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@google.com>

0 files changed, 0 insertions, 0 deletions