usbtty: sometimes input/output oddities

[laforge@…]

In the u-boot > host direction, if u-boot wants to send a lot of characters at
once (e.g. 'mtdparts' or 'nand dump'), sometimes bogus characters are sent to
the host. Must be related to usbtty circular buffer handling somehow.

[alphaone@…]

usbtty also gets confused if it receives many characters at once (i.e. copy and
paste a command)

[elrond+bugzilla.openmoko.org@…]

I can still see all these issues on r2040.

u-boot -> host:

I usually get replicated chars from other (previous) parts of the output.
My current best way to reproduce this: "help", then "date".

host -> u-boot:

Just tested:
If I paste 20 chars into u-boot, I only get the first 18 of them in return.

Note: I have retitled this bug to show more clearly, that it is about both
directions. If someone thinks, that these are unrelated, we can still file a
seperate bug.

[laforge@…]

Fixed in svn rev 2875