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| author | Johan Hovold <jhovold@gmail.com> | 2014-05-26 21:23:48 +0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-05-28 02:04:10 +0400 |
| commit | b1d42efc217fdc1a6a704b344fd902ae52a012c8 (patch) | |
| tree | 8ecdc055e6f6c6b1c794d9b08b131840e0918568 | |
| parent | 89e54e4468338df5a4ab7627c5b8b10786ee43e8 (diff) | |
| download | linux-b1d42efc217fdc1a6a704b344fd902ae52a012c8.tar.xz | |
USB: cdc-acm: minimise no-suspend window during shutdown
Now that acm_set_control() handles runtime PM properly, the only
remaining reason for the PM operations in shutdown is to clear the
needs_remote_wakeup flag before the final put.
Note that this also means that we now need to grab the write_lock to
prevent racing with resume.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/usb/class/cdc-acm.c | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index 91fdc293196f..f038f390db97 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -590,13 +590,22 @@ static void acm_port_shutdown(struct tty_port *port) struct urb *urb; struct acm_wb *wb; int i; - int pm_err; dev_dbg(&acm->control->dev, "%s\n", __func__); - pm_err = usb_autopm_get_interface(acm->control); acm_set_control(acm, acm->ctrlout = 0); + /* + * Need to grab write_lock to prevent race with resume, but no need to + * hold it due to the tty-port initialised flag. + */ + spin_lock_irq(&acm->write_lock); + spin_unlock_irq(&acm->write_lock); + + usb_autopm_get_interface_no_resume(acm->control); + acm->control->needs_remote_wakeup = 0; + usb_autopm_put_interface(acm->control); + for (;;) { urb = usb_get_from_anchor(&acm->delayed); if (!urb) @@ -611,10 +620,6 @@ static void acm_port_shutdown(struct tty_port *port) usb_kill_urb(acm->wb[i].urb); for (i = 0; i < acm->rx_buflimit; i++) usb_kill_urb(acm->read_urbs[i]); - - acm->control->needs_remote_wakeup = 0; - if (!pm_err) - usb_autopm_put_interface(acm->control); } static void acm_tty_cleanup(struct tty_struct *tty) |