drm/vmwgfx: Stop using plane->fb in vmw_kms_helper_dirty()

Instead of plane->fb (which we're going to deprecate for atomic drivers)
we need to look at plane->state->fb. The maze of code leading to
vmw_kms_helper_dirty() wasn't particularly clear, but my analysis
concluded that the calls originating from vmw_*_primary_plane_atomic_update()
all pass in the crtc which means we'll never end up in this branch
of the function. All other callers use drm_modeset_lock_all() somewhere
higher up, which means accessing plane->state is safe.

v2: Drop the comment and make the code do what it did before (Thomas)
v3: Drop the bogus lockdep assert

Cc: Deepak Rawat <drawat@vmware.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: Sinclair Yeh <syeh@vmware.com>
Cc: VMware Graphics <linux-graphics-maintainer@vmware.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180525185045.29689-3-ville.syrjala@linux.intel.com
Reviewed-by: Sinclair Yeh <syeh@vmware.com>

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
index a2a796b..146ea18 100644 (file)
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
@@ -2326,9 +2326,10 @@ int vmw_kms_helper_dirty(struct vmw_private *dev_priv,
        } else {
                list_for_each_entry(crtc, &dev_priv->dev->mode_config.crtc_list,
                                    head) {
-                       if (crtc->primary->fb != &framebuffer->base)
-                               continue;
-                       units[num_units++] = vmw_crtc_to_du(crtc);
+                       struct drm_plane *plane = crtc->primary;
+
+                       if (plane->state->fb == &framebuffer->base)
+                               units[num_units++] = vmw_crtc_to_du(crtc);
                }
        }