[PATCH v3 2/2] drm/imagination: allow probe when no power-domains are described

[Sterling-Ash]

pvr_power_domains_init() currently fails probe with -ENOENT when the
device tree node has no "power-domains" property. On some platforms
(e.g. SpacemiT K3) the GPU power domain is brought up by the bootloader
and is not modeled or managed by Linux, so there is legitimately no
power-domains phandle to attach.

Treat a missing "power-domains" property as "nothing to attach" and
continue probing, rather than failing.

Signed-off-by: Sterling-Ash <liangbaihui at linux.spacemit.com>
---
 drivers/gpu/drm/imagination/pvr_power.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/gpu/drm/imagination/pvr_power.c b/drivers/gpu/drm/imagination/pvr_power.c
index a71d5b35601e..5751e2d814b0 100644
--- a/drivers/gpu/drm/imagination/pvr_power.c
+++ b/drivers/gpu/drm/imagination/pvr_power.c
@@ -635,6 +635,15 @@ int pvr_power_domains_init(struct pvr_device *pvr_dev)
 
 	domain_count = of_count_phandle_with_args(dev->of_node, "power-domains",
 						  "#power-domain-cells");
+	if (domain_count == -ENOENT) {
+		/*
+		 * No "power-domains" property in the device tree: the platform
+		 * handles power domains transparently or at the firmware/bootloader level,
+		 * so there is no domain to attach. Treat this as non-fatal.
+		 */
+		err = 0;
+		goto out;
+	}
 	if (domain_count < 0) {
 		err = domain_count;
 		goto out;
-- 
2.34.1