pycond_timedwait_2.patch prints the delta time in microseconds when deadline is in the past.  Running the patch with the following command:
  python -m test -m test_lru_cache_threaded -v test_functools
gives these results:

a) natively:
  deadline is never in the past and the test run prints only a bunch of 'Ok's.
b) on the x86 emulator:
  Although the test does not hang when python is not patched, the output of the test run, test_lru_cache_threaded-x86-printf.txt, shows that deadline is almost always in the past.
c) on the armv7 emulator:
  The output of the test run, test_lru_cache_threaded-armv7-printf.txt (this is a truncated version, the original file is half a Mbytes long), shows that deadline is always in the past. With the patch, the test does not hang.

It is possible that this problem could be a quirk in the implementation of the qemu emulator, given the results of b), and the fact that the python test suite runs at about the same speed when run natively and on the x86 emulator.