media: omap3isp: fix unbalanced dma_iommu_mapping

The OMAP3 ISP driver manages its MMU mappings through the IOMMU-aware
ARM DMA backend. The current code creates a dma_iommu_mapping and
attaches this to the ISP device, but never detaches the mapping in
either the probe failure paths or the driver remove path resulting
in an unbalanced mapping refcount and a memory leak. Fix this properly.

Reported-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Suman Anna <s-anna@ti.com>
Tested-by: Pavel Machek <pavel@ucw.cz>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/platform/omap3isp/isp.c

@@ -1938,6 +1938,7 @@ error_csi2:
 
 static void isp_detach_iommu(struct isp_device *isp)
 {
+	arm_iommu_detach_device(isp->dev);
 	arm_iommu_release_mapping(isp->mapping);
 	isp->mapping = NULL;
 }
@@ -1954,8 +1955,7 @@ static int isp_attach_iommu(struct isp_device *isp)
 	mapping = arm_iommu_create_mapping(&platform_bus_type, SZ_1G, SZ_2G);
 	if (IS_ERR(mapping)) {
 		dev_err(isp->dev, "failed to create ARM IOMMU mapping\n");
-		ret = PTR_ERR(mapping);
-		goto error;
+		return PTR_ERR(mapping);
 	}
 
 	isp->mapping = mapping;
@@ -1970,7 +1970,8 @@ static int isp_attach_iommu(struct isp_device *isp)
 	return 0;
 
 error:
-	isp_detach_iommu(isp);
+	arm_iommu_release_mapping(isp->mapping);
+	isp->mapping = NULL;
 	return ret;
 }