[PATCH 2/3] usb console,usb-serial: fix regression use of serial->console
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From: Jason Wessel on 16 Sep 2009 23:10 During the 2.6.32 development usb serial tty interface was changed. This change caused the usb serial driver to crash when used as a system console. The open and close of the raw hardware has to be protected by the serial->console variable so either the console code does the open and close or the higher level tty based driver executes the open and close. * In serial_open() the raw open must be protected by serial->console * In serial_down() the test_and_clear_bit must be executed before leaving the function if the device is a serial console * serial_release() should no longer protect for the console condition due to the 2.6.32 interface changes. The actual low level close protection is accounted for in serial_down() Signed-off-by: Jason Wessel <jason.wessel(a)windriver.com> Cc: Greg KH <gregkh(a)suse.de> Cc: Alan Stern <stern(a)rowland.harvard.edu> --- drivers/usb/serial/usb-serial.c | 28 +++++++++++++--------------- 1 files changed, 13 insertions(+), 15 deletions(-) diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c index ff75a35..3d35ed2 100644 --- a/drivers/usb/serial/usb-serial.c +++ b/drivers/usb/serial/usb-serial.c @@ -267,10 +267,14 @@ static int serial_open(struct tty_struct *tty, struct file *filp) if (mutex_lock_interruptible(&port->mutex)) return -ERESTARTSYS; mutex_lock(&serial->disc_mutex); - if (serial->disconnected) + if (serial->disconnected) { retval = -ENODEV; - else - retval = port->serial->type->open(tty, port); + } else { + if (port->console) + retval = 0; + else + retval = port->serial->type->open(tty, port); + } mutex_unlock(&serial->disc_mutex); mutex_unlock(&port->mutex); if (retval) @@ -294,6 +298,12 @@ static void serial_down(struct usb_serial_port *port) { struct usb_serial_driver *drv = port->serial->type; + /* Don't call the close method if the hardware hasn't been + * initialized. + */ + if (!test_and_clear_bit(ASYNCB_INITIALIZED, &port->port.flags)) + return; + /* * The console is magical. Do not hang up the console hardware * or there will be tears. @@ -301,12 +311,6 @@ static void serial_down(struct usb_serial_port *port) if (port->console) return; - /* Don't call the close method if the hardware hasn't been - * initialized. - */ - if (!test_and_clear_bit(ASYNCB_INITIALIZED, &port->port.flags)) - return; - mutex_lock(&port->mutex); if (drv->close) drv->close(port); @@ -353,12 +357,6 @@ static void serial_release(struct tty_struct *tty) struct usb_serial *serial; struct module *owner; - /* The console is magical. Do not hang up the console hardware - * or there will be tears. - */ - if (port->console) - return; - dbg("%s - port %d", __func__, port->number); /* Standard shutdown processing */ -- 1.6.4.rc1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |