drm/i915: Change locking for struct_mutex, v3.
struct_mutex is being locked for every plane in intel_prepare_plane_fb
and intel_cleanup_plane_fb.
Require the caller to hold the mutex, and only acquire the mutex for
each helper call. This way the lock only needs to be acquired
twice in ->atomic_commit(). Once for pinning new framebuffers at the
start, the second time for unpinning old framebuffer.
Changes since v1:
- Use mutex_lock_interruptible instead of i915 variant,
to prevent a deadlock when called from the reset code.
Changes since v2:
- Clarify struct_mutex is locked by the caller.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com> #v1
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 36e7e29..8393759 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -13165,8 +13165,13 @@
return ret;
}
+ ret = mutex_lock_interruptible(&dev->struct_mutex);
+ if (ret)
+ return ret;
+
ret = drm_atomic_helper_prepare_planes(dev, state);
+ mutex_unlock(&dev->struct_mutex);
return ret;
}
@@ -13268,7 +13273,10 @@
/* FIXME: add subpixel order */
drm_atomic_helper_wait_for_vblanks(dev, state);
+
+ mutex_lock(&dev->struct_mutex);
drm_atomic_helper_cleanup_planes(dev, state);
+ mutex_unlock(&dev->struct_mutex);
if (any_ms)
intel_modeset_check_state(dev, state);
@@ -13437,6 +13445,8 @@
* bits. Some older platforms need special physical address handling for
* cursor planes.
*
+ * Must be called with struct_mutex held.
+ *
* Returns 0 on success, negative error code on failure.
*/
int
@@ -13453,10 +13463,6 @@
if (!obj && !old_obj)
return 0;
- ret = i915_mutex_lock_interruptible(dev);
- if (ret)
- return ret;
-
if (old_obj) {
struct drm_crtc_state *crtc_state =
drm_atomic_get_existing_crtc_state(new_state->state, plane->state->crtc);
@@ -13477,7 +13483,7 @@
/* Swallow -EIO errors to allow updates during hw lockup. */
if (ret && ret != -EIO)
- goto out;
+ return ret;
}
if (!obj) {
@@ -13495,9 +13501,6 @@
if (ret == 0)
i915_gem_track_fb(old_obj, obj, intel_plane->frontbuffer_bit);
-out:
- mutex_unlock(&dev->struct_mutex);
-
return ret;
}
@@ -13507,6 +13510,8 @@
* @fb: old framebuffer that was on plane
*
* Cleans up a framebuffer that has just been removed from a plane.
+ *
+ * Must be called with struct_mutex held.
*/
void
intel_cleanup_plane_fb(struct drm_plane *plane,
@@ -13520,7 +13525,6 @@
if (!obj && !old_obj)
return;
- mutex_lock(&dev->struct_mutex);
if (old_obj && (plane->type != DRM_PLANE_TYPE_CURSOR ||
!INTEL_INFO(dev)->cursor_needs_physical))
intel_unpin_fb_obj(old_state->fb, old_state);
@@ -13529,7 +13533,6 @@
if ((old_obj && (old_obj->frontbuffer_bits & intel_plane->frontbuffer_bit)) ||
(obj && !(obj->frontbuffer_bits & intel_plane->frontbuffer_bit)))
i915_gem_track_fb(old_obj, obj, intel_plane->frontbuffer_bit);
- mutex_unlock(&dev->struct_mutex);
}
int