From 21b871582375ed711311fbfae37db91f789ac10a Mon Sep 17 00:00:00 2001 From: Julian Wiedmann Date: Wed, 10 May 2017 19:07:52 +0200 Subject: s390/qeth: unbreak OSM and OSN support [ Upstream commit 2d2ebb3ed0c6acfb014f98e427298673a5d07b82 ] commit b4d72c08b358 ("qeth: bridgeport support - basic control") broke the support for OSM and OSN devices as follows: As OSM and OSN are L2 only, qeth_core_probe_device() does an early setup by loading the l2 discipline and calling qeth_l2_probe_device(). In this context, adding the l2-specific bridgeport sysfs attributes via qeth_l2_create_device_attributes() hits a BUG_ON in fs/sysfs/group.c, since the basic sysfs infrastructure for the device hasn't been established yet. Note that OSN actually has its own unique sysfs attributes (qeth_osn_devtype), so the additional attributes shouldn't be created at all. For OSM, add a new qeth_l2_devtype that contains all the common and l2-specific sysfs attributes. When qeth_core_probe_device() does early setup for OSM or OSN, assign the corresponding devtype so that the ccwgroup probe code creates the full set of sysfs attributes. This allows us to skip qeth_l2_create_device_attributes() in case of an early setup. Any device that can't do early setup will initially have only the generic sysfs attributes, and when it's probed later qeth_l2_probe_device() adds the l2-specific attributes. If an early-setup device is removed (by calling ccwgroup_ungroup()), device_unregister() will - using the devtype - delete the l2-specific attributes before qeth_l2_remove_device() is called. So make sure to not remove them twice. What complicates the issue is that qeth_l2_probe_device() and qeth_l2_remove_device() is also called on a device when its layer2 attribute changes (ie. its layer mode is switched). For early-setup devices this wouldn't work properly - we wouldn't remove the l2-specific attributes when switching to L3. But switching the layer mode doesn't actually make any sense; we already decided that the device can only operate in L2! So just refuse to switch the layer mode on such devices. Note that OSN doesn't have a layer2 attribute, so we only need to special-case OSM. Based on an initial patch by Ursula Braun. Fixes: b4d72c08b358 ("qeth: bridgeport support - basic control") Signed-off-by: Julian Wiedmann Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/s390/net/qeth_l2_sys.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'drivers/s390/net/qeth_l2_sys.c') diff --git a/drivers/s390/net/qeth_l2_sys.c b/drivers/s390/net/qeth_l2_sys.c index 692db49e3d2a..a48ed9e7e168 100644 --- a/drivers/s390/net/qeth_l2_sys.c +++ b/drivers/s390/net/qeth_l2_sys.c @@ -272,3 +272,11 @@ void qeth_l2_setup_bridgeport_attrs(struct qeth_card *card) } else qeth_bridgeport_an_set(card, 0); } + +const struct attribute_group *qeth_l2_attr_groups[] = { + &qeth_device_attr_group, + &qeth_device_blkt_group, + /* l2 specific, see l2_{create,remove}_device_attributes(): */ + &qeth_l2_bridgeport_attr_group, + NULL, +}; -- cgit v1.2.3