This is a note to let you know that I've just added the patch titled drm/vc4: hdmi: Make sure the controller is powered in detect to the 5.12-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drm-vc4-hdmi-make-sure-the-controller-is-powered-in-.patch and it can be found in the queue-5.12 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 955d4445d923c48b8cdd0263a6998f4d767dd84f Author: Maxime Ripard <maxime@xxxxxxxxxx> Date: Tue May 25 11:10:59 2021 +0200 drm/vc4: hdmi: Make sure the controller is powered in detect [ 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> 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; }