On Tue, Jun 23, 2015 at 10:46:00PM +0200, Daniel Vetter wrote:
> Now that dp mst hotplug takes all locks we can amend the locking rules
> for the iterators. This is needed before we can roll these out in the
> atomic code to avoid getting burried in WARNINGs.
>
> Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
> ---
> include/drm/drm_crtc.h | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
> index 3646c47b43de..c1c4f16f01ca 100644
> --- a/include/drm/drm_crtc.h
> +++ b/include/drm/drm_crtc.h
> @@ -1588,14 +1588,16 @@ static inline struct drm_property
> *drm_property_find(struct drm_device *dev,
> list_for_each_entry(crtc, &(dev)->mode_config.crtc_list, head)
>
> #define drm_for_each_connector(connector, dev) \
> - for (WARN_ON(!mutex_is_locked(&(dev)->mode_config.mutex)),
> \
> + for (WARN_ON(!mutex_is_locked(&(dev)->mode_config.mutex) &&
> \
> +
> !drm_modeset_is_locked(&(dev)->mode_config.connection_mutex)), \
> connector = list_first_entry(&(dev)->mode_config.connector_list,
> \
> struct drm_connector, head);
> \
> &connector->head != (&(dev)->mode_config.connector_list);
> \
> connector = list_next_entry(connector, head))
>
> #define drm_for_each_encoder(encoder, dev) \
> - for (WARN_ON(!mutex_is_locked(&(dev)->mode_config.mutex)),
> \
> + for (WARN_ON(!mutex_is_locked(&(dev)->mode_config.mutex) &&
> \
> +
> !drm_modeset_is_locked(&(dev)->mode_config.connection_mutex)), \
> encoder = list_first_entry(&(dev)->mode_config.encoder_list,
> \
> struct drm_encoder, head);
> \
> &encoder->head != (&(dev)->mode_config.encoder_list);
> \
Maybe something like:
// not sure how specifc each lock will end up being
static inline void assert_drm_mode_list_locked(dev)
{
/* lockdep for accuracy and verbose debug reportts,
* WARN_ON for warnings everywhere.
*/
lockdep_assert_held(&dev->mode_config.mutex);
WARN_ON(!(mutex_is_locked(&dev->mode_config.mutex) &&
drm_modeset_is_locked(&dev->mode_config.connection_mutex)));
// Daniel, it is not clear from context whether you mean
// !a && !b, or !(a && b)
}
static inline struct drm_connector *drm_first_connector(dev)
{
assert_drm_mode_list_locked(dev);
return list_first_entry(&dev->mode_config.connector_list,
struct drm_connector, head);
}
#define drm_for_each_connector(connector, dev) \
for (connector = drm_first_connector(dev); \
&connector->head != (&(dev)->mode_config.connector_list);
\
connector = list_next_entry(connector, head))
static inline struct drm_encoder *drm_first_encoder(dev)
{
assert_drm_mode_list_locked(dev);
return list_first_entry(&dev->mode_config.encoder_list,
struct drm_encoder, head);
}
#define drm_for_each_encoder(encoder, dev) \
for (encoder = drm_first_encoder(dev); \
&encoder->head != (&(dev)->mode_config.encoder_list);
\
encoder = list_next_entry(encoder, head))
Usual arguments of reusing code for clarity.
-Chris
--
Chris Wilson, Intel Open Source Technology Centre
