From 2d2ebb3ed0c6acfb014f98e427298673a5d07b82 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 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 --- drivers/s390/net/qeth_core.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'drivers/s390/net/qeth_core.h') diff --git a/drivers/s390/net/qeth_core.h b/drivers/s390/net/qeth_core.h index f6aa21176d89..30bc6105aac3 100644 --- a/drivers/s390/net/qeth_core.h +++ b/drivers/s390/net/qeth_core.h @@ -701,6 +701,7 @@ enum qeth_discipline_id { }; struct qeth_discipline { + const struct device_type *devtype; void (*start_poll)(struct ccw_device *, int, unsigned long); qdio_handler_t *input_handler; qdio_handler_t *output_handler; @@ -875,6 +876,9 @@ extern struct qeth_discipline qeth_l2_discipline; extern struct qeth_discipline qeth_l3_discipline; extern const struct attribute_group *qeth_generic_attr_groups[]; extern const struct attribute_group *qeth_osn_attr_groups[]; +extern const struct attribute_group qeth_device_attr_group; +extern const struct attribute_group qeth_device_blkt_group; +extern const struct device_type qeth_generic_devtype; extern struct workqueue_struct *qeth_wq; int qeth_card_hw_is_reachable(struct qeth_card *); -- cgit v1.2.3-55-g7522