powerpc/512x: Use dma_request_chan() instead dma_request_slave_channel()

dma_request_slave_channel() is a wrapper on top of dma_request_chan()
eating up the error code.

By using dma_request_chan() directly the driver can support deferred
probing against DMA.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191217073730.21249-1-peter.ujfalusi@ti.com

diff --git a/arch/powerpc/platforms/512x/mpc512x_lpbfifo.c b/arch/powerpc/platforms/512x/mpc512x_lpbfifo.c
index 13631f3..04bf6ec 100644 (file)
--- a/arch/powerpc/platforms/512x/mpc512x_lpbfifo.c
+++ b/arch/powerpc/platforms/512x/mpc512x_lpbfifo.c
@@ -434,9 +434,9 @@ static int mpc512x_lpbfifo_probe(struct platform_device *pdev)
        memset(&lpbfifo, 0, sizeof(struct lpbfifo_data));
        spin_lock_init(&lpbfifo.lock);
 
-       lpbfifo.chan = dma_request_slave_channel(&pdev->dev, "rx-tx");
-       if (lpbfifo.chan == NULL)
-               return -EPROBE_DEFER;
+       lpbfifo.chan = dma_request_chan(&pdev->dev, "rx-tx");
+       if (IS_ERR(lpbfifo.chan))
+               return PTR_ERR(lpbfifo.chan);
 
        if (of_address_to_resource(pdev->dev.of_node, 0, &r) != 0) {
                dev_err(&pdev->dev, "bad 'reg' in 'sclpc' device tree node\n");