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authorJames Bottomley <James.Bottomley@HansenPartnership.com>2009-08-01 00:39:36 +0000
committerJames Bottomley <James.Bottomley@suse.de>2009-08-22 17:52:13 -0500
commit163f52b6cf3a639df6a72c7937e0eb88b20f1ef3 (patch)
tree68991096e7ff15e31db28fb0d7bf2e87b1bd01c2 /drivers/misc
parent0124ca9d8ee58b3cd028a23cef2fe225fcfee3b8 (diff)
downloadop-kernel-dev-163f52b6cf3a639df6a72c7937e0eb88b20f1ef3.zip
op-kernel-dev-163f52b6cf3a639df6a72c7937e0eb88b20f1ef3.tar.gz
[SCSI] ses: fix hotplug with multiple devices and expanders
In a situation either with expanders or with multiple enclosure devices, hot add doesn't always work. This is because we try to find a single enclosure device attached to the host. Fix this by looping over all enclosure devices attached to the host and also by making the find loop recognise that the enclosure devices may be expander remote (i.e. not parented by the host). Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
Diffstat (limited to 'drivers/misc')
-rw-r--r--drivers/misc/enclosure.c44
1 files changed, 32 insertions, 12 deletions
diff --git a/drivers/misc/enclosure.c b/drivers/misc/enclosure.c
index 348443b..789d121 100644
--- a/drivers/misc/enclosure.c
+++ b/drivers/misc/enclosure.c
@@ -33,24 +33,44 @@ static DEFINE_MUTEX(container_list_lock);
static struct class enclosure_class;
/**
- * enclosure_find - find an enclosure given a device
- * @dev: the device to find for
+ * enclosure_find - find an enclosure given a parent device
+ * @dev: the parent to match against
+ * @start: Optional enclosure device to start from (NULL if none)
*
- * Looks through the list of registered enclosures to see
- * if it can find a match for a device. Returns NULL if no
- * enclosure is found. Obtains a reference to the enclosure class
- * device which must be released with device_put().
+ * Looks through the list of registered enclosures to find all those
+ * with @dev as a parent. Returns NULL if no enclosure is
+ * found. @start can be used as a starting point to obtain multiple
+ * enclosures per parent (should begin with NULL and then be set to
+ * each returned enclosure device). Obtains a reference to the
+ * enclosure class device which must be released with device_put().
+ * If @start is not NULL, a reference must be taken on it which is
+ * released before returning (this allows a loop through all
+ * enclosures to exit with only the reference on the enclosure of
+ * interest held). Note that the @dev may correspond to the actual
+ * device housing the enclosure, in which case no iteration via @start
+ * is required.
*/
-struct enclosure_device *enclosure_find(struct device *dev)
+struct enclosure_device *enclosure_find(struct device *dev,
+ struct enclosure_device *start)
{
struct enclosure_device *edev;
mutex_lock(&container_list_lock);
- list_for_each_entry(edev, &container_list, node) {
- if (edev->edev.parent == dev) {
- get_device(&edev->edev);
- mutex_unlock(&container_list_lock);
- return edev;
+ edev = list_prepare_entry(start, &container_list, node);
+ if (start)
+ put_device(&start->edev);
+
+ list_for_each_entry_continue(edev, &container_list, node) {
+ struct device *parent = edev->edev.parent;
+ /* parent might not be immediate, so iterate up to
+ * the root of the tree if necessary */
+ while (parent) {
+ if (parent == dev) {
+ get_device(&edev->edev);
+ mutex_unlock(&container_list_lock);
+ return edev;
+ }
+ parent = parent->parent;
}
}
mutex_unlock(&container_list_lock);
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