diff options
| author | Alan Cox <alan@lxorguk.ukuu.org.uk> | 2009-06-11 12:25:25 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-06-11 08:50:56 -0700 |
| commit | 1ec739be75a6cb961a46ba0b1982d0edb7f27558 (patch) | |
| tree | b9e75b3171d1a5b715465b82c9cb2b711e6d5550 | |
| parent | fcc8ac1825d3d0fb81f73bc1a80ebc863168bb56 (diff) | |
tty: Implement a drain delay in the tty port
We need this for devices that cannot flush and wait, but which do not order
data and modem events. Without it we will hang up before all the data
clears the hardware. Needed for the USB changes.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | drivers/char/tty_port.c | 11 | ||||
| -rw-r--r-- | include/linux/tty.h | 3 |
2 files changed, 14 insertions, 0 deletions
diff --git a/drivers/char/tty_port.c b/drivers/char/tty_port.c index 926d4a5593f..4d08b6d27c2 100644 --- a/drivers/char/tty_port.c +++ b/drivers/char/tty_port.c @@ -308,6 +308,17 @@ int tty_port_close_start(struct tty_port *port, struct tty_struct *tty, struct f if (port->flags & ASYNC_INITIALIZED && port->closing_wait != ASYNC_CLOSING_WAIT_NONE) tty_wait_until_sent(tty, port->closing_wait); + if (port->drain_delay) { + unsigned int bps = tty_get_baud_rate(tty); + long timeout; + + if (bps > 1200) + timeout = max_t(long, (HZ * 10 * port->drain_delay) / bps, + HZ / 10); + else + timeout = 2 * HZ; + schedule_timeout_interruptible(timeout); + } return 1; } EXPORT_SYMBOL(tty_port_close_start); diff --git a/include/linux/tty.h b/include/linux/tty.h index 98694364c96..bed5a3d4030 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -201,6 +201,9 @@ struct tty_port { unsigned char *xmit_buf; /* Optional buffer */ int close_delay; /* Close port delay */ int closing_wait; /* Delay for output */ + int drain_delay; /* Set to zero if no pure time + based drain is needed else + set to size of fifo */ }; /* |