media: camss: Do not attach an already attached power domain on MSM8916 platform

The change to dynamically allocated power domains neglected a case of
CAMSS on MSM8916 platform, where a single VFE power domain is neither
attached, linked or managed in runtime in any way explicitly.

This is a special case and it shall be kept as is, because the power
domain management is done outside of the driver, and it's very different
in comparison to all other platforms supported by CAMSS.

Fixes: 6b1814e2 ("media: camss: Allocate power domain resources dynamically")
Signed-off-by: Vladimir Zapolskiy <vladimir.zapolskiy@linaro.org>
Reviewed-by: Robert Foss <robert.foss@linaro.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

drivers/media/platform/qcom/camss/camss.c

@@ -1465,6 +1465,14 @@ static int camss_configure_pd(struct camss *camss)
 		return camss->genpd_num;
 	}
 
+	/*
+	 * If a platform device has just one power domain, then it is attached
+	 * at platform_probe() level, thus there shall be no need and even no
+	 * option to attach it again, this is the case for CAMSS on MSM8916.
+	 */
+	if (camss->genpd_num == 1)
+		return 0;
+
 	camss->genpd = devm_kmalloc_array(dev, camss->genpd_num,
 					  sizeof(*camss->genpd), GFP_KERNEL);
 	if (!camss->genpd)
@@ -1698,6 +1706,9 @@ void camss_delete(struct camss *camss)
 
 	pm_runtime_disable(camss->dev);
 
+	if (camss->genpd_num == 1)
+		return;
+
 	for (i = 0; i < camss->genpd_num; i++) {
 		device_link_del(camss->genpd_link[i]);
 		dev_pm_domain_detach(camss->genpd[i], true);