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drm/omap: fix dma_addr refcounting

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cec4fa7511 ("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: cec4fa7511 ("drm/omap: use refcount API to track the number of users of dma_addr")
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
This commit is contained in:
Tomi Valkeinen 2019-11-14 10:03:43 +02:00
parent d6d07ca19c
commit d9c148cfaf
1 changed files with 4 additions and 0 deletions
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4
drivers/gpu/drm/omapdrm/omap_gem.c
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@ -843,9 +843,13 @@ fail:
*/
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) {