Comment 4 for bug 1397976

Hi,
I've just got the new -proposed kernel with that fix, and got an important regression: it broke tty connection to my devices using FTDI chips.

I haven't fully checked yet, but I think that's because you've cherry-picked commit eafbe67f84761d787802e5113d895a316b6292fe "n_tty: Refactor input_available_p() by call site", without also taking commit a5934804a834f525c9e6289935ceef65b952b101 "n_tty: Fix poll() when TIME_CHAR and MIN_CHAR == 0" (which fixes that first commit).

Note: I'm not affected by the original bug, so cannot comment on the effect of the other commits.

How to reproduce the regression:
? python
> import serial
> p = serial.Serial("/dev/ttyACM0", timeout=1)
> p.read()
SerialException: device reports readiness to read but returned no data (device disconnected?)

Expected:
p.read() waits one second and returns nothing (due to timeout).