staging: speakup: check for null before calling TTY's flush_buffer
authorOkash Khawaja <okash.khawaja@gmail.com>
Wed, 31 May 2017 19:50:12 +0000 (20:50 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sat, 3 Jun 2017 08:38:25 +0000 (17:38 +0900)
commit011cca558b6256ff14464e61c111707415a0484f
tree39ab7695404e4ad40653b348426c0f939c470bc2
parentd0b112ac2ae3738a9f1a86f97dc5fbd23be7e123
staging: speakup: check for null before calling TTY's flush_buffer

We should check the flush_buffer method of a tty for null before
invoking it. Some drivers such as usbserial don't implement
flush_buffer. This will be required for upcoming patches where we expand
spk_ttyio to support more than just ttyS*.

Signed-off-by: Okash Khawaja <okash.khawaja@gmail.com>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/staging/speakup/spk_ttyio.c