driver_find_device() calls get_device() to increment the reference
count once a matching device is found, but there is no put_device() to
balance the reference count. To avoid reference count leakage, add
put_device() to decrease the reference count.

Found by code review.

Cc: stable@vger.kernel.org
Fixes: a31500fe7055 ("drm/tegra: dc: Restore coupling of display controllers")
Signed-off-by: Ma Ke <make24@iscas.ac.cn>
---
 drivers/gpu/drm/tegra/dc.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/tegra/dc.c b/drivers/gpu/drm/tegra/dc.c
index 59d5c1ba145a..6c84bd69b11f 100644
--- a/drivers/gpu/drm/tegra/dc.c
+++ b/drivers/gpu/drm/tegra/dc.c
@@ -3148,6 +3148,7 @@ static int tegra_dc_couple(struct tegra_dc *dc)
 		dc->client.parent = &parent->client;
 
 		dev_dbg(dc->dev, "coupled to %s\n", dev_name(companion));
+		put_device(companion);
 	}
 
 	return 0;
-- 
2.17.1

On Wednesday, October 22, 2025 8:47 PM Ma Ke wrote:
> driver_find_device() calls get_device() to increment the reference
> count once a matching device is found, but there is no put_device() to
> balance the reference count. To avoid reference count leakage, add
> put_device() to decrease the reference count.
> 
> Found by code review.
> 
> Cc: stable@vger.kernel.org
> Fixes: a31500fe7055 ("drm/tegra: dc: Restore coupling of display controllers")
> Signed-off-by: Ma Ke <make24@iscas.ac.cn>
> ---
>  drivers/gpu/drm/tegra/dc.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/gpu/drm/tegra/dc.c b/drivers/gpu/drm/tegra/dc.c
> index 59d5c1ba145a..6c84bd69b11f 100644
> --- a/drivers/gpu/drm/tegra/dc.c
> +++ b/drivers/gpu/drm/tegra/dc.c
> @@ -3148,6 +3148,7 @@ static int tegra_dc_couple(struct tegra_dc *dc)
>  		dc->client.parent = &parent->client;
>  
>  		dev_dbg(dc->dev, "coupled to %s\n", dev_name(companion));
> +		put_device(companion);
>  	}
>  
>  	return 0;
> 

Acked-by: Mikko Perttunen <mperttunen@nvidia.com>