| Message ID | 20191114080343.30704-1-tomi.valkeinen@ti.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/omap: fix dma_addr refcounting | expand |
Hi Tomi, Thank you for the patch. On Thu, Nov 14, 2019 at 10:03:43AM +0200, Tomi Valkeinen wrote: > 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. How about adding a Fixes line ? Fixes: cec4fa7511ef ("drm/omap: use refcount API to track the number of users of dma_addr") > Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > --- > 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) {
On 02/12/2019 14:36, Laurent Pinchart wrote: > Hi Tomi, > > Thank you for the patch. > > On Thu, Nov 14, 2019 at 10:03:43AM +0200, Tomi Valkeinen wrote: >> 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. > > How about adding a Fixes line ? > > Fixes: cec4fa7511ef ("drm/omap: use refcount API to track the number of users of dma_addr") Thanks! I'll add the fixes line. Tomi
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) {
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> --- drivers/gpu/drm/omapdrm/omap_gem.c | 4 ++++ 1 file changed, 4 insertions(+)