2023-08-05 11:52:09

by Karol Herbst

Subject: [PATCH] drm/nouveau/disp: Revert a NULL check inside nouveau_connector_get_modes

The original commit adding that check tried to protect the kenrel against
a potential invalid NULL pointer access.

However we call nouveau_connector_detect_depth once without a native_mode
set on purpose for non LVDS connectors and this broke DP support in a few
cases.

Cc: Olaf Skibbe <[email protected]>
Cc: Lyude Paul <[email protected]>
Closes: https://gitlab.freedesktop.org/drm/nouveau/-/issues/238
Closes: https://gitlab.freedesktop.org/drm/nouveau/-/issues/245
Fixes: 20a2ce87fbaf8 ("drm/nouveau/dp: check for NULL nv_connector->native_mode")
Signed-off-by: Karol Herbst <[email protected]>
---
drivers/gpu/drm/nouveau/nouveau_connector.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_connector.c b/drivers/gpu/drm/nouveau/nouveau_connector.c
index f75c6f09dd2af..a2e0033e8a260 100644
--- a/drivers/gpu/drm/nouveau/nouveau_connector.c
+++ b/drivers/gpu/drm/nouveau/nouveau_connector.c
@@ -967,7 +967,7 @@ nouveau_connector_get_modes(struct drm_connector *connector)
/* Determine display colour depth for everything except LVDS now,
* DP requires this before mode_valid() is called.
*/
- if (connector->connector_type != DRM_MODE_CONNECTOR_LVDS && nv_connector->native_mode)
+ if (connector->connector_type != DRM_MODE_CONNECTOR_LVDS)
nouveau_connector_detect_depth(connector);

/* Find the native mode if this is a digital panel, if we didn't
--
2.41.0

2023-08-07 22:38:52

by Lyude Paul

Subject: Re: [PATCH] drm/nouveau/disp: Revert a NULL check inside nouveau_connector_get_modes

Ugh, thanks for catching this!

Reviewed-by: Lyude Paul <[email protected]>

On Sat, 2023-08-05 at 12:18 +0200, Karol Herbst wrote:
> The original commit adding that check tried to protect the kenrel against
> a potential invalid NULL pointer access.
>
> However we call nouveau_connector_detect_depth once without a native_mode
> set on purpose for non LVDS connectors and this broke DP support in a few
> cases.
>
> Cc: Olaf Skibbe <[email protected]>
> Cc: Lyude Paul <[email protected]>
> Closes: https://gitlab.freedesktop.org/drm/nouveau/-/issues/238
> Closes: https://gitlab.freedesktop.org/drm/nouveau/-/issues/245
> Fixes: 20a2ce87fbaf8 ("drm/nouveau/dp: check for NULL nv_connector->native_mode")
> Signed-off-by: Karol Herbst <[email protected]>
> ---
> drivers/gpu/drm/nouveau/nouveau_connector.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/nouveau/nouveau_connector.c b/drivers/gpu/drm/nouveau/nouveau_connector.c
> index f75c6f09dd2af..a2e0033e8a260 100644
> --- a/drivers/gpu/drm/nouveau/nouveau_connector.c
> +++ b/drivers/gpu/drm/nouveau/nouveau_connector.c
> @@ -967,7 +967,7 @@ nouveau_connector_get_modes(struct drm_connector *connector)
> /* Determine display colour depth for everything except LVDS now,
> * DP requires this before mode_valid() is called.
> */
> - if (connector->connector_type != DRM_MODE_CONNECTOR_LVDS && nv_connector->native_mode)
> + if (connector->connector_type != DRM_MODE_CONNECTOR_LVDS)
> nouveau_connector_detect_depth(connector);
>
> /* Find the native mode if this is a digital panel, if we didn't

--
Cheers,
Lyude Paul (she/her)
Software Engineer at Red Hat