Commit 8567494c authored by Laurentiu Tudor's avatar Laurentiu Tudor Committed by Greg Kroah-Hartman
Browse files

bus: fsl-mc: rescan devices if endpoint not found 



If the endpoint of a device is not yet probed on the bus, force
a rescan of the devices and retry to get a reference to the
endpoint device. If the device is still not found then we assume
it's in a different isolation context (container/DPRC) thus
unavailable and return a permission error.

Signed-off-by: default avatarLaurentiu Tudor <laurentiu.tudor@nxp.com>
Signed-off-by: default avatarRobert-Ionut Alexa <robert-ionut.alexa@nxp.com>
Link: https://lore.kernel.org/r/20210715140718.8513-7-laurentiu.tudor@nxp.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 39243fc1

drivers/bus/fsl-mc/fsl-mc-bus.c

+20 −2
Original line number Diff line number Diff line
@@ -950,10 +950,28 @@ struct fsl_mc_device *fsl_mc_get_endpoint(struct fsl_mc_device *mc_dev) 
	 * We know that the device has an endpoint because we verified by

	 * interrogating the firmware. This is the case when the device was not

	 * yet discovered by the fsl-mc bus, thus the lookup returned NULL.

	 * Differentiate this case by returning EPROBE_DEFER.

	 * Force a rescan of the devices in this container and retry the lookup.

	 */

	if (!endpoint) {

		struct fsl_mc_bus *mc_bus = to_fsl_mc_bus(mc_bus_dev);



		if (mutex_trylock(&mc_bus->scan_mutex)) {

			err = dprc_scan_objects(mc_bus_dev, true);

			mutex_unlock(&mc_bus->scan_mutex);

		}



		if (err < 0)

			return ERR_PTR(err);

	}



	endpoint = fsl_mc_device_lookup(&endpoint_desc, mc_bus_dev);

	/*

	 * This means that the endpoint might reside in a different isolation

	 * context (DPRC/container). Not much to do, so return a permssion

	 * error.

	 */

	if (!endpoint)

		return ERR_PTR(-EPROBE_DEFER);

		return ERR_PTR(-EPERM);



	return endpoint;

}