omap3isp: Defer probe when the IOMMU is not available

commit 7c0f812a upstream.

When the OMAP3 ISP driver is compiled in the kernel the device can be
probed before the corresponding IOMMU is available. Defer the probe in
that case, and fix a crash in the error path.
Reported-by: Javier Martin <javier.martin@vista-silicon.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/media/platform/omap3isp/isp.c

@@ -2249,6 +2249,7 @@ static int isp_probe(struct platform_device *pdev)
 	ret = iommu_attach_device(isp->domain, &pdev->dev);
 	if (ret) {
 		dev_err(&pdev->dev, "can't attach iommu device: %d\n", ret);
+		ret = -EPROBE_DEFER;
 		goto free_domain;
 	}
 
@@ -2287,6 +2288,7 @@ static int isp_probe(struct platform_device *pdev)
 	iommu_detach_device(isp->domain, &pdev->dev);
 free_domain:
 	iommu_domain_free(isp->domain);
+	isp->domain = NULL;
 error_isp:
 	isp_xclk_cleanup(isp);
 	omap3isp_put(isp);