From 5b006000423667ef0f55721fc93e477b31f22d28 Mon Sep 17 00:00:00 2001
From: Maxime Ripard <maxime@cerno.tech>
Date: Fri, 7 May 2021 17:05:09 +0200
Subject: [PATCH] drm/vc4: hdmi: Prevent clock unbalance
Git-commit: 5b006000423667ef0f55721fc93e477b31f22d28
Patch-mainline: v5.14-rc1
References: git-fixes

Since we fixed the hooks to disable the encoder at boot, we now have an
unbalanced clk_disable call at boot since we never enabled them in the
first place.

Let's mimic the state of the hardware and enable the clocks at boot if
the controller is enabled to get the use-count right.

Cc: <stable@vger.kernel.org> # v5.10+
Fixes: 09c438139b8f ("drm/vc4: hdmi: Implement finer-grained hooks")
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210507150515.257424-7-maxime@cerno.tech
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/gpu/drm/vc4/vc4_hdmi.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index c27b287d2053..df9bf85edbea 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -2051,6 +2051,14 @@ static int vc4_hdmi_bind(struct device *dev, struct device *master, void *data)
 	if (vc4_hdmi->variant->reset)
 		vc4_hdmi->variant->reset(vc4_hdmi);
 
+	if ((of_device_is_compatible(dev->of_node, "brcm,bcm2711-hdmi0") ||
+	     of_device_is_compatible(dev->of_node, "brcm,bcm2711-hdmi1")) &&
+	    HDMI_READ(HDMI_VID_CTL) & VC4_HD_VID_CTL_ENABLE) {
+		clk_prepare_enable(vc4_hdmi->pixel_clock);
+		clk_prepare_enable(vc4_hdmi->hsm_clock);
+		clk_prepare_enable(vc4_hdmi->pixel_bvb_clock);
+	}
+
 	pm_runtime_enable(dev);
 
 	drm_simple_encoder_init(drm, encoder, DRM_MODE_ENCODER_TMDS);
-- 
2.26.2