As of now we were starting the registration process and after the device is registered we were checking if the device can be used by the parport. Now lets check it first so that we do not need to go through the registration process only to fail at the end. The original exclusive access check at the end is still there so that we do not get any surprises if two different process registers its device with same parport and with exclusive access at the same time.
Signed-off-by: Sudip Mukherjee <[email protected]> --- Hi Greg, One doubt - if anyone sends any patch regarding parport, it will be addressed to me. so do i need to forward it to you? drivers/parport/share.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/drivers/parport/share.c b/drivers/parport/share.c index 697c6d7..8067f54 100644 --- a/drivers/parport/share.c +++ b/drivers/parport/share.c @@ -708,6 +708,20 @@ parport_register_device(struct parport *port, const char *name, } } + if (flags & PARPORT_DEV_EXCL) { + if (port->physport->devices) { + /* + * If a device is already registered and this new + * device wants exclusive access, then no need to + * continue as we can not grant exclusive access to + * this device. + */ + pr_err("%s: cannot grant exclusive access for device %s\n", + port->name, name); + return NULL; + } + } + /* We up our own module reference count, and that of the port on which a device is to be registered, to ensure that neither of us gets unloaded while we sleep in (e.g.) @@ -827,6 +841,20 @@ parport_register_dev_model(struct parport *port, const char *name, } } + if (par_dev_cb->flags & PARPORT_DEV_EXCL) { + if (port->physport->devices) { + /* + * If a device is already registered and this new + * device wants exclusive access, then no need to + * continue as we can not grant exclusive access to + * this device. + */ + pr_err("%s: cannot grant exclusive access for device %s\n", + port->name, name); + return NULL; + } + } + if (!try_module_get(port->ops->owner)) return NULL; -- 1.8.1.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
