[PATCH 10/12] tty: tidy up the RESET_TERMIOS case

Alan Cox
2012-06-22T15:30:23Z

If we are going to reset the termios then we don't need the driver side
buffers at all as we now have the tty allocation.

Signed-off-by: Alan Cox <alan@linux.intel.com>
---

drivers/tty/tty_io.c | 45 +++++++++++++++++++++++----------------------
1 file changed, 23 insertions(+), 22 deletions(-)

diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index f5c8d4f..14db2a8 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -1249,16 +1249,20 @@ int tty_init_termios(struct tty_struct *tty)
struct ktermios *tp;
int idx = tty->index;

- tp = tty->driver->termios[idx];
- if (tp == NULL) {
- tp = kmalloc(sizeof(struct ktermios), GFP_KERNEL);
- if (tp == NULL)
- return -ENOMEM;
- *tp = tty->driver->init_termios;
- tty->driver->termios[idx] = tp;
- }
- tty->termios = *tp;
-
+ if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS)
+ tty->termios = tty->driver->init_termios;
+ else {
+ tp = tty->driver->termios[idx];
+ if (tp == NULL) {
+ tp = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL);
+ if (tp == NULL)
+ return -ENOMEM;
+ tp[0] = tty->driver->init_termios;
+ tty->driver->termios[idx] = tp;
+ }
+ tty->termios = tp[0];
+ tty->termios_locked = tp[1];
+ }
/* Compatibility until drivers always set this */
tty->termios.c_ispeed = tty_termios_input_baud_rate(&tty->termios);
tty->termios.c_ospeed = tty_termios_baud_rate(&tty->termios);
@@ -1432,16 +1436,9 @@ err_release_tty:

void tty_free_termios(struct tty_struct *tty)
{
- struct ktermios *tp;
int idx = tty->index;
/* Kill this flag and push into drivers for locking etc */
- if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) {
- /* FIXME: Locking on ->termios array */
- tp = tty->driver->termios[idx];
- tty->driver->termios[idx] = NULL;
- kfree(tp);
- }
- else
+ if (!(tty->driver->flags & TTY_DRIVER_RESET_TERMIOS))
*tty->driver->termios[idx] = tty->termios;
}
EXPORT_SYMBOL(tty_free_termios);
@@ -3069,16 +3066,18 @@ static void destruct_tty_driver(struct kref *kref)
* drivers are removed from the kernel.
*/
for (i = 0; i < driver->num; i++) {
- tp = driver->termios[i];
- if (tp) {
- driver->termios[i] = NULL;
- kfree(tp);
+ if (!(driver->flags & TTY_DRIVER_RESET_TERMIOS)) {
+ tp = driver->termios[i];
+ if (tp) {
+ driver->termios[i] = NULL;
+ kfree(tp);
+ }
}
if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV))
tty_unregister_device(driver, i);
}
p = driver->ttys;
proc_tty_unregister_driver(driver);
driver->ttys = NULL;
driver->termios = NULL;
kfree(p);
@@ -3117,6 +3117,7 @@ int tty_register_driver(struct tty_driver *driver)
void **p = NULL;
struct device *d;

+ /* FIXME: at this point we are overallocating for the RESET_TERMIOS case */
if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM) && driver->num) {
p = kzalloc(driver->num * 2 * sizeof(void *), GFP_KERNEL);
if (!p)