From 0282b7f2a874e72c18fcd5a112ccf67f71ba7f5c Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Tue, 29 Jul 2008 12:01:04 -0400 Subject: [PATCH] usb-serial: don't release unregistered minors This patch (as1121) fixes a bug in the USB serial core. When a device is unregistered, the core will give back its minors -- even if the device hasn't been assigned any! The patch reserves the highest minor value (255) to mean that no minor was assigned. It also removes some dead code and does a small style fixup. Signed-off-by: Alan Stern Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/usb/serial/usb-serial.c | 7 +++---- include/linux/usb/serial.h | 3 ++- 2 files changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c index 8c2d531eede..b157c48e8b7 100644 --- a/drivers/usb/serial/usb-serial.c +++ b/drivers/usb/serial/usb-serial.c @@ -122,9 +122,6 @@ static void return_serial(struct usb_serial *serial) dbg("%s", __func__); - if (serial == NULL) - return; - for (i = 0; i < serial->num_ports; ++i) serial_table[serial->minor + i] = NULL; } @@ -142,7 +139,8 @@ static void destroy_serial(struct kref *kref) serial->type->shutdown(serial); /* return the minor range that this device had */ - return_serial(serial); + if (serial->minor != SERIAL_TTY_NO_MINOR) + return_serial(serial); for (i = 0; i < serial->num_ports; ++i) serial->port[i]->port.count = 0; @@ -575,6 +573,7 @@ static struct usb_serial *create_serial(struct usb_device *dev, serial->interface = interface; kref_init(&serial->kref); mutex_init(&serial->disc_mutex); + serial->minor = SERIAL_TTY_NO_MINOR; return serial; } diff --git a/include/linux/usb/serial.h b/include/linux/usb/serial.h index 09a3e6a7518..655341d0f53 100644 --- a/include/linux/usb/serial.h +++ b/include/linux/usb/serial.h @@ -17,7 +17,8 @@ #include #define SERIAL_TTY_MAJOR 188 /* Nice legal number now */ -#define SERIAL_TTY_MINORS 255 /* loads of devices :) */ +#define SERIAL_TTY_MINORS 254 /* loads of devices :) */ +#define SERIAL_TTY_NO_MINOR 255 /* No minor was assigned */ /* The maximum number of ports one device can grab at once */ #define MAX_NUM_PORTS 8 -- 2.20.1