[PATCH 4.4 18/66] tty: improve tty_insert_flip_char() slow path

4.4-stable review patch. If anyone has any objections, please let me know. -- From: Arnd Bergmann commit 065ea0a7afd64d6cf3464bdd1d8cd227527e2045 upstream. While working on improving the fast path of tty_insert_flip_char(), I noticed that by calling

[PATCH 4.4 18/66] tty: improve tty_insert_flip_char() slow path

4.4-stable review patch. If anyone has any objections, please let me know. -- From: Arnd Bergmann commit 065ea0a7afd64d6cf3464bdd1d8cd227527e2045 upstream. While working on improving the fast path of tty_insert_flip_char(), I noticed that by calling tty_buffer_request_room(),