tree 258cbb425a03d5f444014d32c59a22f13d4ed492
parent eff6937a46e096eb35c16a391617b7a5e098a30c
author Thomas Pfaff <tpfaff@pcs.com> 1230904033 +0000
committer Linus Torvalds <torvalds@linux-foundation.org> 1230920380 -0800

tty: N_TTY SIGIO only works for read

The N_TTY ldisc layer does not send SIGIO POLL_OUTs correctly when output is
possible due to flawed handling of the TTY_DO_WRITE_WAKEUP bit. It will
either send no SIGIOs at all or on every tty wakeup.

The fix is to set the bit when the tty driver write would block and test
and clear it on write wakeup.

[Merged with existing N_TTY patches and a small buglet fixed -- Alan]

Signed-off-by: Thomas Pfaff <tpfaff@pcs.com>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>