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Commit c921a974 authored by Stefan Richter's avatar Stefan Richter
Browse files

ieee1394: don't drop nodes during bus reset series 

nodemgr_node_probe checked for generation increments too late and
therefore prematurely reported nodes as "suspended".

Fixes http://bugzilla.kernel.org/show_bug.cgi?id=11349

.  Reported and
tested by Damien Benoist.

Signed-off-by: default avatarStefan Richter <stefanr@s5r6.in-berlin.de>
parent 6848408a

drivers/ieee1394/nodemgr.c

+21 −19
Original line number Diff line number Diff line
@@ -1574,6 +1574,9 @@ static int node_probe(struct device *dev, void *data) 
	struct probe_param *p = data;

	struct node_entry *ne;



	if (p->generation != get_hpsb_generation(p->hi->host))

		return -EAGAIN;



	ne = container_of(dev, struct node_entry, node_dev);

	if (ne->needs_probe == p->probe_now)

		nodemgr_probe_ne(p->hi, ne, p->generation);
@@ -1582,41 +1585,40 @@ static int node_probe(struct device *dev, void *data) 


static void nodemgr_node_probe(struct host_info *hi, int generation)

{

	struct hpsb_host *host = hi->host;

	struct probe_param p;



	p.hi = hi;

	p.generation = generation;

	/* Do some processing of the nodes we've probed. This pulls them

	/*

	 * Do some processing of the nodes we've probed. This pulls them

	 * into the sysfs layer if needed, and can result in processing of

	 * unit-directories, or just updating the node and it's

	 * unit-directories.

	 *

	 * Run updates before probes. Usually, updates are time-critical

	 * while probes are time-consuming. (Well, those probes need some

	 * improvement...) */



	 * while probes are time-consuming.

	 *

	 * Meanwhile, another bus reset may have happened. In this case we

	 * skip everything here and let the next bus scan handle it.

	 * Otherwise we may prematurely remove nodes which are still there.

	 */

	p.probe_now = false;

	class_for_each_device(&nodemgr_ne_class, NULL, &p, node_probe);

	p.probe_now = true;

	class_for_each_device(&nodemgr_ne_class, NULL, &p, node_probe);

	if (class_for_each_device(&nodemgr_ne_class, NULL, &p, node_probe) != 0)

		return;



	/* If we had a bus reset while we were scanning the bus, it is

	 * possible that we did not probe all nodes.  In that case, we

	 * skip the clean up for now, since we could remove nodes that

	 * were still on the bus.  Another bus scan is pending which will

	 * do the clean up eventually.

	 *

	p.probe_now = true;

	if (class_for_each_device(&nodemgr_ne_class, NULL, &p, node_probe) != 0)

		return;

	/*

	 * Now let's tell the bus to rescan our devices. This may seem

	 * like overhead, but the driver-model core will only scan a

	 * device for a driver when either the device is added, or when a

	 * new driver is added. A bus reset is a good reason to rescan

	 * devices that were there before.  For example, an sbp2 device

	 * may become available for login, if the host that held it was

	 * just removed.  */



	if (generation == get_hpsb_generation(host))

		if (bus_rescan_devices(&ieee1394_bus_type))

	 * just removed.

	 */

	if (bus_rescan_devices(&ieee1394_bus_type) != 0)

		HPSB_DEBUG("bus_rescan_devices had an error");

}