dca: check against empty dca_domains list before unregister provider

When providers get blocked unregister_dca_providers() is called ending up with dca_providers and dca_domain lists emptied. Dca should be prevented from trying to unregister any provider if dca_domain list is found empty. Cc: <[email protected]> Reported-by: Jiang Liu <[email protected]> Tested-by: Gaohuai Han <[email protected]> Signed-off-by: Maciej Sosnowski <[email protected]> Signed-off-by: Dan Williams <[email protected]>
wafgo · Jan 8, 2013 · c419fcf · c419fcf
1 parent 6decffd
commit c419fcf
Showing 1 changed file with 5 additions and 0 deletions.
diff --git a/drivers/dca/dca-core.c b/drivers/dca/dca-core.c
@@ -420,6 +420,11 @@ void unregister_dca_provider(struct dca_provider *dca, struct device *dev)
 
 	raw_spin_lock_irqsave(&dca_lock, flags);
 
+	if (list_empty(&dca_domains)) {
+		raw_spin_unlock_irqrestore(&dca_lock, flags);
+		return;
+	}
+
 	list_del(&dca->node);
 
 	pci_rc = dca_pci_rc_from_dev(dev);