[PATCH] drm/etnaviv: fix DMA direction handling for cached read/write buffers

[Lucas Stach]

The dma sync operation needs to be done with DMA_BIDIRECTIONAL when
the BO is prepared for both read and write operations. With the
current inverted if ladder it would only be synced for DMA_FROM_DEVICE.

Fixes: a8c21a5451d8 ("drm/etnaviv: add initial etnaviv DRM driver")
Signed-off-by: Lucas Stach <l.stach at pengutronix.de>
---
 drivers/gpu/drm/etnaviv/etnaviv_gem.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem.c b/drivers/gpu/drm/etnaviv/etnaviv_gem.c
index b5f73502e3dd..d788a27aacb8 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_gem.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gem.c
@@ -356,12 +356,14 @@ static void *etnaviv_gem_vmap_impl(struct etnaviv_gem_object *obj)
 
 static inline enum dma_data_direction etnaviv_op_to_dma_dir(u32 op)
 {
-	if (op & ETNA_PREP_READ)
+	if (op & (ETNA_PREP_READ | ETNA_PREP_WRITE))
+		return DMA_BIDIRECTIONAL;
+	else if (op & ETNA_PREP_READ)
 		return DMA_FROM_DEVICE;
 	else if (op & ETNA_PREP_WRITE)
 		return DMA_TO_DEVICE;
-	else
-		return DMA_BIDIRECTIONAL;
+
+	return DMA_NONE;
 }
 
 int etnaviv_gem_cpu_prep(struct drm_gem_object *obj, u32 op,
-- 
2.39.2