[PATCH] drm/vc4: hdmi: take i2c adapter module reference

From: Johan Hovold

Date: Thu Jul 16 2026 - 09:34:07 EST


The i2c subsystem currently blocks during adapter deregistration
whenever there are consumers holding a reference.

Switch to using of_get_i2c_adapter_by_node() which also takes a
reference to the adapter module so that an attempt to unload the module
while in use fails gracefully instead of blocking uninterruptibly.

Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
---
drivers/gpu/drm/vc4/vc4_hdmi.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index a161d3b00a25..40c28e23ea46 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -3208,11 +3208,11 @@ static int vc4_hdmi_runtime_resume(struct device *dev)
return ret;
}

-static void vc4_hdmi_put_ddc_device(void *ptr)
+static void vc4_hdmi_put_ddc(void *ptr)
{
struct vc4_hdmi *vc4_hdmi = ptr;

- put_device(&vc4_hdmi->ddc->dev);
+ i2c_put_adapter(vc4_hdmi->ddc);
}

static int vc4_hdmi_bind(struct device *dev, struct device *master, void *data)
@@ -3266,14 +3266,14 @@ static int vc4_hdmi_bind(struct device *dev, struct device *master, void *data)
return -ENODEV;
}

- vc4_hdmi->ddc = of_find_i2c_adapter_by_node(ddc_node);
+ vc4_hdmi->ddc = of_get_i2c_adapter_by_node(ddc_node);
of_node_put(ddc_node);
if (!vc4_hdmi->ddc) {
drm_err(drm, "Failed to get ddc i2c adapter by node\n");
return -EPROBE_DEFER;
}

- ret = devm_add_action_or_reset(dev, vc4_hdmi_put_ddc_device, vc4_hdmi);
+ ret = devm_add_action_or_reset(dev, vc4_hdmi_put_ddc, vc4_hdmi);
if (ret)
return ret;

--
2.54.0