2021-10-25 01:56:30

by He Ying

Subject: [PATCH] drm: Fix wrong use of connector in vop_get_edp_connector

From the comments of drm_for_each_connector_iter(), we know
that "connector is only valid within the list body, if you
want to use connector after calling drm_connector_list_iter_end()
then you need to grab your own reference first using
drm_connector_get()". So fix the wrong use of connector
according to the comments and then call drm_connector_put()
after using connector finishes.

Signed-off-by: He Ying <[email protected]>
Fixes: 2cbeb64f6c70 ("drm/rockchip: use drm_for_each_connector_iter()")
---
drivers/gpu/drm/rockchip/rockchip_drm_vop.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
index a25b98b7f5bd..469922ad29fa 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
@@ -1581,19 +1581,19 @@ static void vop_crtc_reset(struct drm_crtc *crtc)
#ifdef CONFIG_DRM_ANALOGIX_DP
static struct drm_connector *vop_get_edp_connector(struct vop *vop)
{
- struct drm_connector *connector;
+ struct drm_connector *connector = NULL;
struct drm_connector_list_iter conn_iter;

drm_connector_list_iter_begin(vop->drm_dev, &conn_iter);
drm_for_each_connector_iter(connector, &conn_iter) {
if (connector->connector_type == DRM_MODE_CONNECTOR_eDP) {
- drm_connector_list_iter_end(&conn_iter);
- return connector;
+ drm_connector_get(connector);
+ break;
}
}
drm_connector_list_iter_end(&conn_iter);

- return NULL;
+ return connector;
}

static int vop_crtc_set_crc_source(struct drm_crtc *crtc,
@@ -1614,6 +1614,7 @@ static int vop_crtc_set_crc_source(struct drm_crtc *crtc,
else
ret = -EINVAL;

+ drm_connector_put(connector);
return ret;
}

--
2.17.1

2021-11-09 11:43:10

by He Ying

Subject: Re: [PATCH] drm: Fix wrong use of connector in vop_get_edp_connector

kindly ping...

?? 2021/10/25 9:55, He Ying д??:
> >From the comments of drm_for_each_connector_iter(), we know
> that "connector is only valid within the list body, if you
> want to use connector after calling drm_connector_list_iter_end()
> then you need to grab your own reference first using
> drm_connector_get()". So fix the wrong use of connector
> according to the comments and then call drm_connector_put()
> after using connector finishes.
>
> Signed-off-by: He Ying <[email protected]>
> Fixes: 2cbeb64f6c70 ("drm/rockchip: use drm_for_each_connector_iter()")
> ---
> drivers/gpu/drm/rockchip/rockchip_drm_vop.c | 9 +++++----
> 1 file changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
> index a25b98b7f5bd..469922ad29fa 100644
> --- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
> +++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
> @@ -1581,19 +1581,19 @@ static void vop_crtc_reset(struct drm_crtc *crtc)
> #ifdef CONFIG_DRM_ANALOGIX_DP
> static struct drm_connector *vop_get_edp_connector(struct vop *vop)
> {
> - struct drm_connector *connector;
> + struct drm_connector *connector = NULL;
> struct drm_connector_list_iter conn_iter;
>
> drm_connector_list_iter_begin(vop->drm_dev, &conn_iter);
> drm_for_each_connector_iter(connector, &conn_iter) {
> if (connector->connector_type == DRM_MODE_CONNECTOR_eDP) {
> - drm_connector_list_iter_end(&conn_iter);
> - return connector;
> + drm_connector_get(connector);
> + break;
> }
> }
> drm_connector_list_iter_end(&conn_iter);
>
> - return NULL;
> + return connector;
> }
>
> static int vop_crtc_set_crc_source(struct drm_crtc *crtc,
> @@ -1614,6 +1614,7 @@ static int vop_crtc_set_crc_source(struct drm_crtc *crtc,
> else
> ret = -EINVAL;
>
> + drm_connector_put(connector);
> return ret;
> }
>