From 83ef344a7539aa55a787790bc036f0bf3466e191 Mon Sep 17 00:00:00 2001 From: "brian@murphy.dk" Date: Wed, 29 Jun 2005 16:53:29 -0700 Subject: [PATCH] [PATCH] USB: fix usb reference count bug in cdc-acm driver This increases the reference count on the usb cdc acm control interface which is referred to by the tty interface provided by the driver. This allows the deferred removal of the tty after the physical device is disconnected if the tty is held open at the time of disconnection. Signed-off-by: brian@murphy.dk Signed-off-by: Greg Kroah-Hartman --- drivers/usb/class/cdc-acm.c | 31 ++++++++++++++++--------------- 1 file changed, 16 insertions(+), 15 deletions(-) diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index 69e859e0f5..adff5a77e3 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -422,6 +422,17 @@ bail_out: return -EIO; } +static void acm_tty_unregister(struct acm *acm) +{ + tty_unregister_device(acm_tty_driver, acm->minor); + usb_put_intf(acm->control); + acm_table[acm->minor] = NULL; + usb_free_urb(acm->ctrlurb); + usb_free_urb(acm->readurb); + usb_free_urb(acm->writeurb); + kfree(acm); +} + static void acm_tty_close(struct tty_struct *tty, struct file *filp) { struct acm *acm = tty->driver_data; @@ -436,14 +447,8 @@ static void acm_tty_close(struct tty_struct *tty, struct file *filp) usb_kill_urb(acm->ctrlurb); usb_kill_urb(acm->writeurb); usb_kill_urb(acm->readurb); - } else { - tty_unregister_device(acm_tty_driver, acm->minor); - acm_table[acm->minor] = NULL; - usb_free_urb(acm->ctrlurb); - usb_free_urb(acm->readurb); - usb_free_urb(acm->writeurb); - kfree(acm); - } + } else + acm_tty_unregister(acm); } up(&open_sem); } @@ -905,7 +910,8 @@ skip_normal_probe: usb_driver_claim_interface(&acm_driver, data_interface, acm); - tty_register_device(acm_tty_driver, minor, &intf->dev); + usb_get_intf(control_interface); + tty_register_device(acm_tty_driver, minor, &control_interface->dev); acm_table[minor] = acm; usb_set_intfdata (intf, acm); @@ -954,12 +960,7 @@ static void acm_disconnect(struct usb_interface *intf) usb_driver_release_interface(&acm_driver, acm->data); if (!acm->used) { - tty_unregister_device(acm_tty_driver, acm->minor); - acm_table[acm->minor] = NULL; - usb_free_urb(acm->ctrlurb); - usb_free_urb(acm->readurb); - usb_free_urb(acm->writeurb); - kfree(acm); + acm_tty_unregister(acm); up(&open_sem); return; } -- 2.39.5