drm/sun4i: backend: Fix probe failure with multiple backends

Commit e0d072782c73 ("dma-mapping: introduce DMA range map, supplanting
dma_pfn_offset") introduced a regression in our code since the second
backed to probe will now get -EINVAL back from dma_direct_set_offset and
will prevent the entire DRM device from probing.

Ignore -EINVAL as a temporary measure to get it back working, before
removing that call entirely.

Fixes: e0d072782c73 ("dma-mapping: introduce DMA range map, supplanting dma_pfn_offset")
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/sun4i/sun4i_backend.c b/drivers/gpu/drm/sun4i/sun4i_backend.c
index 77497b4..55960cb 100644 (file)
--- a/drivers/gpu/drm/sun4i/sun4i_backend.c
+++ b/drivers/gpu/drm/sun4i/sun4i_backend.c
@@ -814,9 +814,15 @@ static int sun4i_backend_bind(struct device *dev, struct device *master,
                 *
                 * XXX(hch): this has no business in a driver and needs to move
                 * to the device tree.
+                *
+                * If we have two subsequent calls to dma_direct_set_offset
+                * returns -EINVAL. Unfortunately, this happens when we have two
+                * backends in the system, and will result in the driver
+                * reporting an error while it has been setup properly before.
+                * Ignore EINVAL, but it should really be removed eventually.
                 */
                ret = dma_direct_set_offset(drm->dev, PHYS_OFFSET, 0, SZ_4G);
-               if (ret)
+               if (ret && ret != -EINVAL)
                        return ret;
        }