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author | Peter Hurley <peter@hurleysoftware.com> | 2014-10-16 16:54:18 -0400 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-11-05 18:53:54 -0800 |
commit | 479e9b94fdce7bc46f669831012fc12f56696fd7 (patch) | |
tree | e51d28533aa68a3234e0ce4a6f21bb5b59417997 /drivers/tty/serial/serial_core.c | |
parent | tty: Flush ldisc buffer atomically with tty flip buffers (diff) | |
download | linux-dev-479e9b94fdce7bc46f669831012fc12f56696fd7.tar.xz linux-dev-479e9b94fdce7bc46f669831012fc12f56696fd7.zip |
serial: Refactor uart_flush_buffer() from uart_close()
In the context of the final tty & port close, flushing the tx
ring buffer after the hardware has already been shutdown and
the ring buffer freed is neither required nor desirable.
uart_flush_buffer() performs 3 operations:
1. Resets tx ring buffer indices, but the tx ring buffer has
already been freed and the indices are reset if the port is
re-opened.
2. Calls uart driver's flush_buffer() method
5 in-tree uart drivers define flush_buffer() methods:
amba-pl011, atmel-serial, imx, serial-tegra, timbuart
These have been refactored into the shutdown() method, if
required.
3. Kicks the ldisc for more writing, but this is undesirable.
The file handle is being released; any waiting writer will
will be kicked out by tty_release() with a warning. Further,
the N_TTY ldisc may generate SIGIO for a file handle which
is no longer valid.
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/serial/serial_core.c')
-rw-r--r-- | drivers/tty/serial/serial_core.c | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index 1166c52e51f4..787d67f74bd9 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -1361,7 +1361,6 @@ static void uart_close(struct tty_struct *tty, struct file *filp) mutex_lock(&port->mutex); uart_shutdown(tty, state); - uart_flush_buffer(tty); tty_ldisc_flush(tty); |