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SubjectRe: [PATCH 5.10 016/101] drm/vc4: hdmi: Make sure the controller is powered in detect
Hi!

> [ 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.

If the WARN_ON ever triggers, we'll get unbalance on pm usage
counts. This should use pm_runtime_get_sync().

Plus, we don't really need to duplicate code at function exit.

Signed-off-by: Pavel Machek <pavel@denx.de>

> +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
> @@ -146,6 +146,8 @@ 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)
> @@ -167,10 +169,12 @@ 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;
> }
>

diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index 88a8cb840cd5..3b145f9f6c87 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -146,7 +146,7 @@ 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));
+ WARN_ON(pm_runtime_get_sync(&vc4_hdmi->pdev->dev));

if (vc4_hdmi->hpd_gpio) {
if (gpio_get_value_cansleep(vc4_hdmi->hpd_gpio) ^
@@ -168,12 +168,9 @@ vc4_hdmi_connector_detect(struct drm_connector *connector, bool force)
kfree(edid);
}
}
+ } else
+ cec_phys_addr_invalidate(vc4_hdmi->cec_adap);

- 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;
}
--
DENX Software Engineering GmbH, Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
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