From: Maxime Ripard <maxime@xxxxxxxxxx> [ Upstream commit 9984d6664ce9dcbbc713962539eaf7636ea246c2 ] 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@xxxxxxxxxx> Reviewed-by: Dave Stevenson <dave.stevenson@xxxxxxxxxxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/20210525091059.234116-4-maxime@xxxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- 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 84e218365045..8106b5634fe1 100644 --- a/drivers/gpu/drm/vc4/vc4_hdmi.c +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c @@ -159,6 +159,8 @@ 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) { if (gpio_get_value_cansleep(vc4_hdmi->hpd_gpio) ^ vc4_hdmi->hpd_active_low) @@ -180,10 +182,12 @@ 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; } -- 2.30.2