dma-coherent: fix rmem_dma_device_init regression

My recent bug fix introduced another bug, which caused rmem_dma_device_init
to always fail, as rmem->priv is never set to anything.

This restores the previous behavior, calling dma_init_coherent_memory()
whenever ->priv is NULL.

Fixes: d35b0996fef3 ("dma-coherent: fix dma_declare_coherent_memory() logic error")
Reported-by: Roy Pledge <roy.pledge@nxp.com>
Tested-by: Roy Pledge <roy.pledge@nxp.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

1 files changed, 9 insertions, 10 deletions

diff --git a/drivers/base/dma-coherent.c b/drivers/base/dma-coherent.c
index a39b2166b145..744f64f43454 100644
--- a/drivers/base/dma-coherent.c
+++ b/drivers/base/dma-coherent.c
@@ -348,16 +348,15 @@ static int rmem_dma_device_init(struct reserved_mem *rmem, struct device *dev)
         struct dma_coherent_mem *mem = rmem->priv;
         int ret;
 
-        if (!mem)
-                return -ENODEV;
-
-        ret = dma_init_coherent_memory(rmem->base, rmem->base, rmem->size,
-                                       DMA_MEMORY_EXCLUSIVE, &mem);
-
-        if (ret) {
-                pr_err("Reserved memory: failed to init DMA memory pool at %pa, size %ld MiB\n",
-                        &rmem->base, (unsigned long)rmem->size / SZ_1M);
-                return ret;
+        if (!mem) {
+                ret = dma_init_coherent_memory(rmem->base, rmem->base,
+                                               rmem->size,
+                                               DMA_MEMORY_EXCLUSIVE, &mem);
+                if (ret) {
+                        pr_err("Reserved memory: failed to init DMA memory pool at %pa, size %ld MiB\n",
+                                &rmem->base, (unsigned long)rmem->size / SZ_1M);
+                        return ret;
+                }
         }
         mem->use_dev_dma_pfn_offset = true;
         rmem->priv = mem;