Alan Stern wrote:
> On Wed, 16 Sep 2009, Jason Wessel wrote:
>
>
>> 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@xxxxxxxxxxxxx>
>> Cc: Greg KH <gregkh@xxxxxxx>
>> Cc: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
>>
>> ---
>> 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)
>>
>
> This part of the patch shouldn't be necessary. The console device
> should always be open.
>
>
With your other patch you just mentioned, I absolutely agree. This does
not need to be tracked in this manner and I don't believe this patch is
needed either.
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
