diff mbox series

[v3] Return only active connectors for get_resources ioctl

Message ID 20181129110921.5832-1-stanislav.lisovskiy@intel.com (mailing list archive)
State New, archived
Headers show
Series [v3] Return only active connectors for get_resources ioctl | expand

Commit Message

Lisovskiy, Stanislav Nov. 29, 2018, 11:09 a.m. UTC
Currently kernel might allocate different connector ids
for the same outputs in case of DP MST, which seems to
confuse userspace. There are can be different connector
ids in the list, which could be assigned to the same
output, while being in different states.
This results in issues, like external displays staying
blank after quick unplugging and plugging back(bug #106250).
Returning only active DP connectors fixes the issue.

v2: Removed caps from the title

v3: Refactored initial condition to look more compact.
    Thanks to Chris Wilson for giving a hint.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=106250
Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
---
 drivers/gpu/drm/drm_mode_config.c | 6 ++++++
 1 file changed, 6 insertions(+)

Comments

Greg KH Nov. 29, 2018, 11:21 a.m. UTC | #1
On Thu, Nov 29, 2018 at 01:09:21PM +0200, Stanislav Lisovskiy wrote:
> Currently kernel might allocate different connector ids
> for the same outputs in case of DP MST, which seems to
> confuse userspace. There are can be different connector
> ids in the list, which could be assigned to the same
> output, while being in different states.
> This results in issues, like external displays staying
> blank after quick unplugging and plugging back(bug #106250).
> Returning only active DP connectors fixes the issue.
> 
> v2: Removed caps from the title
> 
> v3: Refactored initial condition to look more compact.
>     Thanks to Chris Wilson for giving a hint.
> 
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=106250
> Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
> ---
>  drivers/gpu/drm/drm_mode_config.c | 6 ++++++
>  1 file changed, 6 insertions(+)

<formletter>

This is not the correct way to submit patches for inclusion in the
stable kernel tree.  Please read:
    https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
for how to do this properly.

</formletter>
Lyude Paul Nov. 29, 2018, 7:06 p.m. UTC | #2
On Thu, 2018-11-29 at 13:09 +0200, Stanislav Lisovskiy wrote:
> Currently kernel might allocate different connector ids
> for the same outputs in case of DP MST, which seems to
> confuse userspace. There are can be different connector
> ids in the list, which could be assigned to the same
> output, while being in different states.
> This results in issues, like external displays staying
> blank after quick unplugging and plugging back(bug #106250).
> Returning only active DP connectors fixes the issue.
> 
> v2: Removed caps from the title
> 
> v3: Refactored initial condition to look more compact.
>     Thanks to Chris Wilson for giving a hint.
> 
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=106250
> Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
> ---
>  drivers/gpu/drm/drm_mode_config.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/drivers/gpu/drm/drm_mode_config.c
> b/drivers/gpu/drm/drm_mode_config.c
> index ee80788f2c40..3e2cd959a66a 100644
> --- a/drivers/gpu/drm/drm_mode_config.c
> +++ b/drivers/gpu/drm/drm_mode_config.c
> @@ -143,22 +143,28 @@ int drm_mode_getresources(struct drm_device *dev, void
> *data,
>  	drm_connector_list_iter_begin(dev, &conn_iter);
>  	count = 0;
>  	connector_id = u64_to_user_ptr(card_res->connector_id_ptr);
> +	DRM_DEBUG_KMS("GetResources: writing connectors start");
>  	drm_for_each_connector_iter(connector, &conn_iter) {
>  		/* only expose writeback connectors if userspace understands
> them */
>  		if (!file_priv->writeback_connectors &&
>  		    (connector->connector_type ==
> DRM_MODE_CONNECTOR_WRITEBACK))
>  			continue;
>  
> +		if (READ_ONCE(connector->registration_state) !=
> DRM_CONNECTOR_REGISTERED)
> +			continue;
> +
This conditional should just use drm_connector_is_unregistered() instead I'm
fairly sure.

>  		if (drm_lease_held(file_priv, connector->base.id)) {
>  			if (count < card_res->count_connectors &&
>  			    put_user(connector->base.id, connector_id +
> count)) {
>  				drm_connector_list_iter_end(&conn_iter);
>  				return -EFAULT;
>  			}
> +			DRM_DEBUG_KMS("GetResources: connector %s", connector-
> >name);
>  			count++;
>  		}
>  	}
>  	card_res->count_connectors = count;
> +	DRM_DEBUG_KMS("GetResources: writing connectors end - count %d",
> count);
>  	drm_connector_list_iter_end(&conn_iter);
>  
>  	return ret;
Jani Nikula Dec. 4, 2018, 12:45 p.m. UTC | #3
On Thu, 29 Nov 2018, Stanislav Lisovskiy <stanislav.lisovskiy@intel.com> wrote:
> Currently kernel might allocate different connector ids
> for the same outputs in case of DP MST, which seems to
> confuse userspace. There are can be different connector
> ids in the list, which could be assigned to the same
> output, while being in different states.
> This results in issues, like external displays staying
> blank after quick unplugging and plugging back(bug #106250).
> Returning only active DP connectors fixes the issue.

Some nitpicks here...

The patch subject lacks a prefix.

>
> v2: Removed caps from the title
>
> v3: Refactored initial condition to look more compact.
>     Thanks to Chris Wilson for giving a hint.
>
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=106250
> Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
> ---
>  drivers/gpu/drm/drm_mode_config.c | 6 ++++++
>  1 file changed, 6 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_mode_config.c b/drivers/gpu/drm/drm_mode_config.c
> index ee80788f2c40..3e2cd959a66a 100644
> --- a/drivers/gpu/drm/drm_mode_config.c
> +++ b/drivers/gpu/drm/drm_mode_config.c
> @@ -143,22 +143,28 @@ int drm_mode_getresources(struct drm_device *dev, void *data,
>  	drm_connector_list_iter_begin(dev, &conn_iter);
>  	count = 0;
>  	connector_id = u64_to_user_ptr(card_res->connector_id_ptr);
> +	DRM_DEBUG_KMS("GetResources: writing connectors start");

I think the added debugs here are too verbose. You should probably
separate the debugs from the actual change here.

Note also that the logging functions already add the function name, so
"GetResources:" is redundant. Also "\n" is missing.

>  	drm_for_each_connector_iter(connector, &conn_iter) {
>  		/* only expose writeback connectors if userspace understands them */
>  		if (!file_priv->writeback_connectors &&
>  		    (connector->connector_type == DRM_MODE_CONNECTOR_WRITEBACK))
>  			continue;
>  
> +		if (READ_ONCE(connector->registration_state) != DRM_CONNECTOR_REGISTERED)
> +			continue;
> +
>  		if (drm_lease_held(file_priv, connector->base.id)) {
>  			if (count < card_res->count_connectors &&
>  			    put_user(connector->base.id, connector_id + count)) {
>  				drm_connector_list_iter_end(&conn_iter);
>  				return -EFAULT;
>  			}
> +			DRM_DEBUG_KMS("GetResources: connector %s", connector->name);

Please look around, the connector logging is fairly consistent
throughout.

BR,
Jani.

>  			count++;
>  		}
>  	}
>  	card_res->count_connectors = count;
> +	DRM_DEBUG_KMS("GetResources: writing connectors end - count %d", count);
>  	drm_connector_list_iter_end(&conn_iter);
>  
>  	return ret;
diff mbox series

Patch

diff --git a/drivers/gpu/drm/drm_mode_config.c b/drivers/gpu/drm/drm_mode_config.c
index ee80788f2c40..3e2cd959a66a 100644
--- a/drivers/gpu/drm/drm_mode_config.c
+++ b/drivers/gpu/drm/drm_mode_config.c
@@ -143,22 +143,28 @@  int drm_mode_getresources(struct drm_device *dev, void *data,
 	drm_connector_list_iter_begin(dev, &conn_iter);
 	count = 0;
 	connector_id = u64_to_user_ptr(card_res->connector_id_ptr);
+	DRM_DEBUG_KMS("GetResources: writing connectors start");
 	drm_for_each_connector_iter(connector, &conn_iter) {
 		/* only expose writeback connectors if userspace understands them */
 		if (!file_priv->writeback_connectors &&
 		    (connector->connector_type == DRM_MODE_CONNECTOR_WRITEBACK))
 			continue;
 
+		if (READ_ONCE(connector->registration_state) != DRM_CONNECTOR_REGISTERED)
+			continue;
+
 		if (drm_lease_held(file_priv, connector->base.id)) {
 			if (count < card_res->count_connectors &&
 			    put_user(connector->base.id, connector_id + count)) {
 				drm_connector_list_iter_end(&conn_iter);
 				return -EFAULT;
 			}
+			DRM_DEBUG_KMS("GetResources: connector %s", connector->name);
 			count++;
 		}
 	}
 	card_res->count_connectors = count;
+	DRM_DEBUG_KMS("GetResources: writing connectors end - count %d", count);
 	drm_connector_list_iter_end(&conn_iter);
 
 	return ret;