From 68cab9e975fc1c6a47f75613eec6db2725a9fbc7 Mon Sep 17 00:00:00 2001
From: Maxime Ripard <maxime@cerno.tech>
Date: Wed, 22 Sep 2021 14:54:19 +0200
Subject: drm/vc4: hdmi: Make sure the controller is powered in detect
Git-commit: 0f5251339eda7f7eb7bd4467607ae1d01b24e129
Patch-mainline: v5.17-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225
If the HPD GPIO is not available and drm_probe_ddc fails, we end up
reading the HDMI_HOTPLUG register, but the controller might be powered
off resulting in a CPU hang. Make sure we have the power domain and the
HSM clock powered during the detect cycle to prevent the hang from
happening.
Fixes: 4f6e3d66ac52 ("drm/vc4: Add runtime PM support to the HDMI encoder driver")
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Reviewed-by: Nicolas Saenz Julienne <nsaenz@kernel.org>
Tested-by: Nicolas Saenz Julienne <nsaenz@kernel.org>
Tested-by: Michael Stapelberg <michael@stapelberg.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210922125419.4125779-6-maxime@cerno.tech
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/vc4/vc4_hdmi.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index 63b07087d37e..f7e48bc6cb11 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -168,6 +168,8 @@ vc4_hdmi_connector_detect(struct drm_connector *connector, bool force)
struct vc4_hdmi *vc4_hdmi = connector_to_vc4_hdmi(connector);
bool connected = false;
+ WARN_ON(pm_runtime_resume_and_get(&vc4_hdmi->pdev->dev));
+
if (vc4_hdmi->hpd_gpio &&
gpiod_get_value_cansleep(vc4_hdmi->hpd_gpio)) {
connected = true;
@@ -188,10 +190,12 @@ vc4_hdmi_connector_detect(struct drm_connector *connector, bool force)
}
}
+ pm_runtime_put(&vc4_hdmi->pdev->dev);
return connector_status_connected;
}
cec_phys_addr_invalidate(vc4_hdmi->cec_adap);
+ pm_runtime_put(&vc4_hdmi->pdev->dev);
return connector_status_disconnected;
}
--
2.38.1