From 0a245982e60458f29bea8bfa40f6115edc855a35 Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Fri, 5 Apr 2013 16:08:13 -0700 Subject: [PATCH] staging: comedi: serial2002: factor (*poll) busy wait out of tty_read() Factor the (*poll) busy wait code out of tty_read() so the indent level can be reduced and tty_read() is a bit cleaner. Signed-off-by: H Hartley Sweeten Cc: Ian Abbott Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/serial2002.c | 53 +++++++++++---------- 1 file changed, 28 insertions(+), 25 deletions(-) diff --git a/drivers/staging/comedi/drivers/serial2002.c b/drivers/staging/comedi/drivers/serial2002.c index 75c86ae6f844..ecf8ca2080f0 100644 --- a/drivers/staging/comedi/drivers/serial2002.c +++ b/drivers/staging/comedi/drivers/serial2002.c @@ -102,6 +102,33 @@ static int __tty_readb(struct file *f, unsigned char *buf) return f->f_op->read(f, p, 1, &f->f_pos); } +static void tty_read_poll_wait(struct file *f, int timeout) +{ + struct poll_wqueues table; + struct timeval start, now; + + do_gettimeofday(&start); + poll_initwait(&table); + while (1) { + long elapsed; + int mask; + + mask = f->f_op->poll(f, &table.pt); + if (mask & (POLLRDNORM | POLLRDBAND | POLLIN | + POLLHUP | POLLERR)) { + break; + } + do_gettimeofday(&now); + elapsed = (1000000 * (now.tv_sec - start.tv_sec) + + now.tv_usec - start.tv_usec); + if (elapsed > timeout) + break; + set_current_state(TASK_INTERRUPTIBLE); + schedule_timeout(((timeout - elapsed) * HZ) / 10000); + } + poll_freewait(&table); +} + #if 0 /* * On 2.6.26.3 this occaisonally gave me page faults, worked around by @@ -132,31 +159,7 @@ static int tty_read(struct file *f, int timeout) oldfs = get_fs(); set_fs(KERNEL_DS); if (f->f_op->poll) { - struct poll_wqueues table; - struct timeval start, now; - - do_gettimeofday(&start); - poll_initwait(&table); - while (1) { - long elapsed; - int mask; - - mask = f->f_op->poll(f, &table.pt); - if (mask & (POLLRDNORM | POLLRDBAND | POLLIN | - POLLHUP | POLLERR)) { - break; - } - do_gettimeofday(&now); - elapsed = - (1000000 * (now.tv_sec - start.tv_sec) + - now.tv_usec - start.tv_usec); - if (elapsed > timeout) - break; - set_current_state(TASK_INTERRUPTIBLE); - schedule_timeout(((timeout - - elapsed) * HZ) / 10000); - } - poll_freewait(&table); + tty_read_poll_wait(f, timeout); if (__tty_readb(f, &ch) == 1) result = ch; -- 2.34.1