Merge tag 'drm-misc-fixes-2024-04-18' of https://gitlab.freedesktop.org/drm/misc/kernel into drm-fixes

Short summary of fixes pull:

nouveau:
- dp: Don't probe DP ports twice
- nv04: Fix OOB access
- nv50: Disable AUX bus for disconnected DP ports
- nvkm: Fix race condition

panel:
- Don't unregister DSI devices in several drivers

ttm:
- Stop pooling cached NUMA pages

v3d:
- Fix enabled_ns increment

vmwgfx:
- Fix PRIME import/export
- Fix CRTC's atomic check for primary planes
- Sort plane formats by preference

Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20240418072229.GA8983@localhost.localdomain

1 files changed, 6 insertions, 1 deletions

diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/instmem/nv50.c b/drivers/gpu/drm/nouveau/nvkm/subdev/instmem/nv50.c
index a7f3fc342d87..dd5b5a17ece0 100644
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/instmem/nv50.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/instmem/nv50.c
@@ -222,8 +222,11 @@ nv50_instobj_acquire(struct nvkm_memory *memory)
 	void __iomem *map = NULL;
 
 	/* Already mapped? */
-	if (refcount_inc_not_zero(&iobj->maps))
+	if (refcount_inc_not_zero(&iobj->maps)) {
+		/* read barrier match the wmb on refcount set */
+		smp_rmb();
 		return iobj->map;
+	}
 
 	/* Take the lock, and re-check that another thread hasn't
 	 * already mapped the object in the meantime.
@@ -250,6 +253,8 @@ nv50_instobj_acquire(struct nvkm_memory *memory)
 			iobj->base.memory.ptrs = &nv50_instobj_fast;
 		else
 			iobj->base.memory.ptrs = &nv50_instobj_slow;
+		/* barrier to ensure the ptrs are written before refcount is set */
+		smp_wmb();
 		refcount_set(&iobj->maps, 1);
 	}