Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxxx>
---
Documentation/DocBook/gpu.tmpl | 16 ----------------
drivers/gpu/drm/drm_modeset_lock.c | 11 +++++++++--
2 files changed, 9 insertions(+), 18 deletions(-)
diff --git a/Documentation/DocBook/gpu.tmpl b/Documentation/DocBook/gpu.tmpl
index d755d53615d7..cb130514cedf 100644
--- a/Documentation/DocBook/gpu.tmpl
+++ b/Documentation/DocBook/gpu.tmpl
@@ -1092,22 +1092,6 @@ int max_width, max_height;</synopsis>
operation.
</para>
</sect2>
- <sect2>
- <title>Locking</title>
- <para>
- Beside some lookup structures with their own locking (which is hidden
- behind the interface functions) most of the modeset state is protected
- by the <code>dev-<mode_config.lock</code> mutex and additionally
- per-crtc locks to allow cursor updates, pageflips and similar operations
- to occur concurrently with background tasks like output detection.
- Operations which cross domains like a full modeset always grab all
- locks. Drivers there need to protect resources shared between crtcs with
- additional locking. They also need to be careful to always grab the
- relevant crtc locks if a modset functions touches crtc state, e.g. for
- load detection (which does only grab the <code>mode_config.lock</code>
- to allow concurrent screen updates on live crtcs).
- </para>
- </sect2>
</sect1>
<!-- Internals: kms initialization and cleanup -->
diff --git a/drivers/gpu/drm/drm_modeset_lock.c b/drivers/gpu/drm/drm_modeset_lock.c
index e3a4adf03e7b..f33ebe638a28 100644
--- a/drivers/gpu/drm/drm_modeset_lock.c
+++ b/drivers/gpu/drm/drm_modeset_lock.c
@@ -30,12 +30,12 @@
*
* As KMS moves toward more fine grained locking, and atomic ioctl where
* userspace can indirectly control locking order, it becomes necessary
- * to use ww_mutex and acquire-contexts to avoid deadlocks. But because
+ * to use &ww_mutex and acquire-contexts to avoid deadlocks. But because
* the locking is more distributed around the driver code, we want a bit
* of extra utility/tracking out of our acquire-ctx. This is provided
* by drm_modeset_lock / drm_modeset_acquire_ctx.
*
- * For basic principles of ww_mutex, see: Documentation/locking/ww-mutex-design.txt
+ * For basic principles of &ww_mutex, see: Documentation/locking/ww-mutex-design.txt
*
* The basic usage pattern is to:
*
@@ -51,6 +51,13 @@
* ... do stuff ...
* drm_modeset_drop_locks(&ctx);
* drm_modeset_acquire_fini(&ctx);
+ *
+ * On top of of these per-object locks using &ww_mutex there's also an overall
+ * dev->mode_config.lock, for protecting everything else. Mostly this means
+ * probe state of connectors, and preventing hotplug add/removal of connectors.
+ *
+ * Finally there's a bunch of dedicated locks to protect drm core internal
+ * lists and lookup data structures.
*/
/**
--
2.8.1
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