dev_get_drvdata simply returns the driver data part of drm_dev, which has its lifetime bound to the drm_dev. So only drop the reference in the error paths, on success they will get dropped later.

Cc: stable@vger.kernel.org Fixes: 9ba2556cef1df ("drm/mediatek: clean up driver data initialisation") Signed-off-by: Sjoerd Simons sjoerd@collabora.com --- drivers/gpu/drm/mediatek/mtk_drm_drv.c | 22 ++++++++++++++++------ 1 file changed, 16 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c b/drivers/gpu/drm/mediatek/mtk_drm_drv.c index 7841f59c52ee772dba3de416f410604f5f13eef2..c85fbecce9d6f0ade700e047e067ee7f9250f037 100644 --- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c +++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c @@ -373,7 +373,7 @@ static int mtk_drm_match(struct device *dev, const void *data) static bool mtk_drm_get_all_drm_priv(struct device *dev) { struct mtk_drm_private *drm_priv = dev_get_drvdata(dev); - struct mtk_drm_private *all_drm_priv[MAX_CRTC]; + struct mtk_drm_private *all_drm_priv[MAX_CRTC] = { NULL, }; struct mtk_drm_private *temp_drm_priv; struct device_node *phandle = dev->parent->of_node; const struct of_device_id *of_id; @@ -399,16 +399,22 @@ static bool mtk_drm_get_all_drm_priv(struct device *dev) continue;

temp_drm_priv = dev_get_drvdata(drm_dev); - put_device(drm_dev); - if (!temp_drm_priv) + if (!temp_drm_priv) { + put_device(drm_dev); continue; + }

- if (temp_drm_priv->data->main_len) + if (temp_drm_priv->data->main_len) { all_drm_priv[CRTC_MAIN] = temp_drm_priv; - else if (temp_drm_priv->data->ext_len) + } else if (temp_drm_priv->data->ext_len) { all_drm_priv[CRTC_EXT] = temp_drm_priv; - else if (temp_drm_priv->data->third_len) + } else if (temp_drm_priv->data->third_len) { all_drm_priv[CRTC_THIRD] = temp_drm_priv; + } else { + dev_warn(drm_dev, "Could not determine crtc type"); + put_device(drm_dev); + continue; + }

if (temp_drm_priv->mtk_drm_bound) cnt++; @@ -427,6 +433,10 @@ static bool mtk_drm_get_all_drm_priv(struct device *dev) return true; }

+ for (i = 0; i < MAX_CRTC; i++) + if (all_drm_priv[i]) + put_device(all_drm_priv[i]->dev); + return false; }

--- base-commit: 22b5e8cde1db67c64b83fc0e4e1ab166cacff246 change-id: 20251002-mtk-drm-refcount-e0f718d9364a

Best regards,