From: Maxime Ripard <maxime@cerno.tech>
Date: Thu, 19 Aug 2021 13:59:27 +0000 (+0200)
Subject: drm/vc4: hdmi: Make sure the controller is powered up during bind
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=9c6e4f6ed1d61d5f46946e5c151ceb279eedadb1;p=linux.git

drm/vc4: hdmi: Make sure the controller is powered up during bind

In the bind hook, we actually need the device to have the HSM clock
running during the final part of the display initialisation where we
reset the controller and initialise the CEC component.

Failing to do so will result in a complete, silent, hang of the CPU.

Fixes: 411efa18e4b0 ("drm/vc4: hdmi: Move the HSM clock enable to runtime_pm")
Link: https://patchwork.freedesktop.org/patch/msgid/20210819135931.895976-3-maxime@cerno.tech
Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
---

diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index 7a6b7cac8af3d..104078f10fc69 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -2199,6 +2199,18 @@ static int vc4_hdmi_bind(struct device *dev, struct device *master, void *data)
 	if (ret)
 		goto err_put_ddc;
 
+	/*
+	 * We need to have the device powered up at this point to call
+	 * our reset hook and for the CEC init.
+	 */
+	ret = vc4_hdmi_runtime_resume(dev);
+	if (ret)
+		goto err_put_ddc;
+
+	pm_runtime_get_noresume(dev);
+	pm_runtime_set_active(dev);
+	pm_runtime_enable(dev);
+
 	if (vc4_hdmi->variant->reset)
 		vc4_hdmi->variant->reset(vc4_hdmi);
 
@@ -2210,8 +2222,6 @@ static int vc4_hdmi_bind(struct device *dev, struct device *master, void *data)
 		clk_prepare_enable(vc4_hdmi->pixel_bvb_clock);
 	}
 
-	pm_runtime_enable(dev);
-
 	drm_simple_encoder_init(drm, encoder, DRM_MODE_ENCODER_TMDS);
 	drm_encoder_helper_add(encoder, &vc4_hdmi_encoder_helper_funcs);
 
@@ -2235,6 +2245,8 @@ static int vc4_hdmi_bind(struct device *dev, struct device *master, void *data)
 			     vc4_hdmi_debugfs_regs,
 			     vc4_hdmi);
 
+	pm_runtime_put_sync(dev);
+
 	return 0;
 
 err_free_cec:
@@ -2245,6 +2257,7 @@ err_destroy_conn:
 	vc4_hdmi_connector_destroy(&vc4_hdmi->connector);
 err_destroy_encoder:
 	drm_encoder_cleanup(encoder);
+	pm_runtime_put_sync(dev);
 	pm_runtime_disable(dev);
 err_put_ddc:
 	put_device(&vc4_hdmi->ddc->dev);