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

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

[Johan Hovold]

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@kernel.org>
---
 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

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

[Maíra Canal]

On Thu, 16 Jul 2026 15:24:48 +0200, Johan Hovold wrote:
> 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.
> 
> [...]

Applied, thanks!

[1/1] drm/vc4: hdmi: take i2c adapter module reference
      commit: 7a4b7122a623e3d57fc15cf843a9d45fbd72c6ab

Best regards,
- Maíra