USB failure when updating SD using OFW
|Reported by:||wad||Owned by:||wmb@…|
|Component:||ofw - open firmware||Version:||1.75-A2|
|Keywords:||XO-1.75||Cc:||gary, wad, martin.langhoff|
|Deployments affected:||Action Needed:||no action|
On many if not all 1.75 A2 motherboards, an attempt to use fs-update to update the internal/external SD or eMMC will result in a "Short read of zdata file" error message from OFW.
The crashing usually happens either around block 50 or around block 1200.
This was tested running OFW version Q4A10i. On motherboards that have shown this failure, running a wear-levelling test from Linux on the USB device doesn't find any errors.
I spent some time looking at the power rails (Vmain, +3.3V, +5V_USB, Vin). There doesn't seem to be any abnormal activity when OFW fails. The voltage spikes due to the Vmain power supply switching transient are slightly larger when running OFW fs-update than when running the Linux tests, but successful efforts to reduce the spikes didn't have any effect on the frequency of crashing.
Increasing the voltage of Vmain to 1.35V from 1.25V didn't have any effect on the crash frequency.