[PATCH v4 8/8] drm/nouveau: Call pm_runtime_get_noresume() from hpd handlers

[Lyude Paul]

We can't and don't need to try resuming the device from our hotplug
handlers, but hotplug events are generally something we'd like to keep
the device awake for whenever possible. So, grab a PM ref safely in our
hotplug handlers using pm_runtime_get_noresume() and mark the device as
busy once we're finished.

Signed-off-by: Lyude Paul <lyude@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Cc: Lukas Wunner <lukas@xxxxxxxxx>
Cc: Karol Herbst <karolherbst@xxxxxxxxx>
---
 drivers/gpu/drm/nouveau/nouveau_connector.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/gpu/drm/nouveau/nouveau_connector.c b/drivers/gpu/drm/nouveau/nouveau_connector.c
index 8409c3f2c3a1..5a8e8c1ad647 100644
--- a/drivers/gpu/drm/nouveau/nouveau_connector.c
+++ b/drivers/gpu/drm/nouveau/nouveau_connector.c
@@ -1152,6 +1152,11 @@ nouveau_connector_hotplug(struct nvif_notify *notify)
 	const char *name = connector->name;
 	struct nouveau_encoder *nv_encoder;
 
+	/* Resuming the device here isn't possible; but the suspend PM ops
+	 * will wait for us to finish our work before disabling us so this
+	 * should be enough
+	 */
+	pm_runtime_get_noresume(drm->dev->dev);
 	nv_connector->hpd_task = current;
 
 	if (rep->mask & NVIF_NOTIFY_CONN_V0_IRQ) {
@@ -1171,6 +1176,9 @@ nouveau_connector_hotplug(struct nvif_notify *notify)
 	}
 
 	nv_connector->hpd_task = NULL;
+
+	pm_runtime_mark_last_busy(drm->dev->dev);
+	pm_runtime_put_autosuspend(drm->dev->dev);
 	return NVIF_NOTIFY_KEEP;
 }
 
-- 
2.17.1