From d9c148cfaf0a99296ad7c92fb8b65952196053ec Mon Sep 17 00:00:00 2001
From: Tomi Valkeinen <tomi.valkeinen@ti.com>
Date: Thu, 14 Nov 2019 10:03:43 +0200
Subject: drm/omap: fix dma_addr refcounting
Git-commit: d9c148cfaf0a99296ad7c92fb8b65952196053ec
Patch-mainline: v5.5-rc1
References: bsc#1152472
cec4fa7511ef7a73eb635834e9d85b25a5b47a98 ("drm/omap: use refcount API to
track the number of users of dma_addr") changed omap_gem.c to use
refcounting API to track dma_addr uses. However, the driver only tracks
the refcounts for non-contiguous buffers, and the patch didn't fully
take this in account.
After the patch, the driver always decreased refcount in omap_gem_unpin,
instead of decreasing the refcount only for non-contiguous buffers. This
leads to refcounting mismatch.
As for the contiguous cases the refcount is never increased, fix this
issue by returning from omap_gem_unpin if the buffer being unpinned is
contiguous.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191114080343.30704-1-tomi.valkeinen@ti.com
Fixes: cec4fa7511ef ("drm/omap: use refcount API to track the number of users of dma_addr")
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
---
drivers/gpu/drm/omapdrm/omap_gem.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/gpu/drm/omapdrm/omap_gem.c b/drivers/gpu/drm/omapdrm/omap_gem.c
index e518d93ca6df..d08ae95ecc0a 100644
--- a/drivers/gpu/drm/omapdrm/omap_gem.c
+++ b/drivers/gpu/drm/omapdrm/omap_gem.c
@@ -843,9 +843,13 @@ int omap_gem_pin(struct drm_gem_object *obj, dma_addr_t *dma_addr)
*/
static void omap_gem_unpin_locked(struct drm_gem_object *obj)
{
+ struct omap_drm_private *priv = obj->dev->dev_private;
struct omap_gem_object *omap_obj = to_omap_bo(obj);
int ret;
+ if (omap_gem_is_contiguous(omap_obj) || !priv->has_dmm)
+ return;
+
if (refcount_dec_and_test(&omap_obj->dma_addr_cnt)) {
ret = tiler_unpin(omap_obj->block);
if (ret) {
--
2.28.0