From: Dan Williams <dan.j.williams@intel.com>
Date: Thu, 4 Dec 2008 00:17:07 +0000 (-0700)
Subject: dmaengine: protect 'id' from concurrent registrations
X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=b0b42b16ff2b90f17bc1a4308366c9beba4b276e;p=deliverable%2Flinux.git

dmaengine: protect 'id' from concurrent registrations

There is a possibility to have two devices registered with the same id.

Cc: <stable@kernel.org>
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---

diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index 5317e08221ec..657996517374 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -388,7 +388,10 @@ int dma_async_device_register(struct dma_device *device)
 
 	init_completion(&device->done);
 	kref_init(&device->refcount);
+
+	mutex_lock(&dma_list_mutex);
 	device->dev_id = id++;
+	mutex_unlock(&dma_list_mutex);
 
 	/* represent channels in sysfs. Probably want devs too */
 	list_for_each_entry(chan, &device->channels, device_node) {