From: Maxime Ripard maxime@cerno.tech
[ Upstream commit 0f5251339eda7f7eb7bd4467607ae1d01b24e129 ]
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-maxim... Signed-off-by: Sasha Levin sashal@kernel.org --- 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 63b07087d37e8..f7e48bc6cb114 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; }