On 2/28/25 11:10 AM, Alexander Stein wrote:
Hi,
diff --git a/drivers/gpu/drm/panthor/panthor_device.c b/drivers/gpu/drm/panthor/panthor_device.c
index 51ee9cae94504..4348b7e917b64 100644
--- a/drivers/gpu/drm/panthor/panthor_device.c
+++ b/drivers/gpu/drm/panthor/panthor_device.c
@@ -75,6 +75,58 @@ static int panthor_reset_init(struct panthor_device *ptdev)
return 0;
}
+/* Generic power domain handling code, see drivers/gpu/drm/tiny/simpledrm.c */
+static void panthor_detach_genpd(void *res)
+{
+ struct panthor_device *ptdev = res;
+ int i;
+
+ if (ptdev->pwr_dom_count <= 1)
+ return;
+
+ for (i = ptdev->pwr_dom_count - 1; i >= 0; i--)
+ dev_pm_domain_detach(ptdev->pwr_dom_devs[i], true);
+}
+
+static int panthor_genpd_init(struct panthor_device *ptdev)
+{
+ struct device *dev = ptdev->base.dev;
+ int i, ret;
+
+ ptdev->pwr_dom_count = of_count_phandle_with_args(dev->of_node, "power-domains",
+ "#power-domain-cells");
+ /*
+ * Single power-domain devices are handled by driver core nothing to do
+ * here. The same for device nodes without "power-domains" property.
+ */
+ if (ptdev->pwr_dom_count <= 1)
+ return 0;
+
+ if (ptdev->pwr_dom_count > ARRAY_SIZE(ptdev->pwr_dom_devs)) {
+ drm_warn(&ptdev->base, "Too many power domains (%d) for this device\n",
+ ptdev->pwr_dom_count);
+ return -EINVAL;
+ }
+
+ for (i = 0; i < ptdev->pwr_dom_count; i++) {
+ ptdev->pwr_dom_devs[i] = dev_pm_domain_attach_by_id(dev, i);
+ if (!IS_ERR(ptdev->pwr_dom_devs[i]))
+ continue;
+
+ ret = PTR_ERR(ptdev->pwr_dom_devs[i]);
+ if (ret != -EPROBE_DEFER) {
+ drm_warn(&ptdev->base, "pm_domain_attach_by_id(%u) failed: %d\n", i, ret);
+ continue;
Is it a good idea to continue if a power-domain is missing? Any access might
stuck completely. IMHO returning an error is more sensible.
Also some dev_err_probe() should be added here.
Fixed both, thanks .
