Low latency mode for serial driver (i386) broken

[Martin Koegler <e9925248@stud4.tuwien.ac.at>]

Receiving bytes over a serial line with low latency mode causes a
deadlock (at least on 2.6.7+2.6.10 on x86), which stop the computer
from responding. R/W access to /dev/ttySx and a device, which sends
bytes to the computer, are sufficient to exploit it.

There were some messages about it on lkml.

The kernel sources 2.6.10-5 seem to contain no fix for it. In
Bitkeeper Repository, it is fixed by the following small patch:

http://linux.bkbits.net:8080/linux-2.6/cset%4042084ee5WBMJKW89M3BdT38Ykkl5eA?nav=index.html|ChangeSet@-1d

I think, it should be easy backportable to older versions.

mfg Martin Kögler
PS: Please CC me on replies.