6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Stefan Wahren <wahrenst@xxxxxxx>
[ Upstream commit f1a54e860b1bc8d824925b5a77f510913880e8d6 ]
The commit 0f5251339eda ("drm/vc4: hdmi: Make sure the controller is
powered in detect") introduced the necessary power management handling
to avoid register access while controller is powered down.
Unfortunately it just print a warning if pm_runtime_resume_and_get()
fails and proceed anyway.
This could happen during suspend to idle. So we must assume it is unsafe
to access the HDMI register. So bail out properly.
Fixes: 0f5251339eda ("drm/vc4: hdmi: Make sure the controller is powered in detect")
Signed-off-by: Stefan Wahren <wahrenst@xxxxxxx>
Reviewed-by: Maíra Canal <mcanal@xxxxxxxxxx>
Acked-by: Maxime Ripard <mripard@xxxxxxxxxx>
Signed-off-by: Maíra Canal <mcanal@xxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20240821214052.6800-3-wahrenst@xxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/gpu/drm/vc4/vc4_hdmi.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index 643754fa6a8ad..c6e986f71a26f 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -458,6 +458,7 @@ static int vc4_hdmi_connector_detect_ctx(struct drm_connector *connector,
{
struct vc4_hdmi *vc4_hdmi = connector_to_vc4_hdmi(connector);
enum drm_connector_status status = connector_status_disconnected;
+ int ret;
/*
* NOTE: This function should really take vc4_hdmi->mutex, but
@@ -470,7 +471,12 @@ static int vc4_hdmi_connector_detect_ctx(struct drm_connector *connector,
* the lock for now.
*/
- WARN_ON(pm_runtime_resume_and_get(&vc4_hdmi->pdev->dev));
+ ret = pm_runtime_resume_and_get(&vc4_hdmi->pdev->dev);
+ if (ret) {
+ drm_err_once(connector->dev, "Failed to retain HDMI power domain: %d\n",
+ ret);
+ return connector_status_unknown;
+ }
if (vc4_hdmi->hpd_gpio) {
if (gpiod_get_value_cansleep(vc4_hdmi->hpd_gpio))
--
2.43.0
