ASoC: dwc: Fix PIO mode initialization

We can no longer rely on the return value of
devm_snd_dmaengine_pcm_register(...) to check if the DMA
handle is declared in the DT.

Previously this check activated PIO mode but currently
dma_request_chan returns either a valid channel or -EPROBE_DEFER.

In order to activate PIO mode check instead if the interrupt
line is declared. This reflects better what is documented in
the DT bindings (see Documentation/devicetree/bindings/sound/
designware-i2s.txt).

Also, initialize use_pio variable which was never being set
causing PIO mode to never work.

Signed-off-by: Jose Abreu <joabreu@synopsys.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/dwc/designware_i2s.c b/sound/soc/dwc/designware_i2s.c
index 2998954a1c7459e02c3397956e690a276120f06d..bdf8398cbc81b68b445f202636e8949db5e5cae5 100644 (file)
--- a/sound/soc/dwc/designware_i2s.c
+++ b/sound/soc/dwc/designware_i2s.c
@@ -681,22 +681,19 @@ static int dw_i2s_probe(struct platform_device *pdev)
        }
 
        if (!pdata) {
-               ret = devm_snd_dmaengine_pcm_register(&pdev->dev, NULL, 0);
-               if (ret == -EPROBE_DEFER) {
-                       dev_err(&pdev->dev,
-                               "failed to register PCM, deferring probe\n");
-                       return ret;
-               } else if (ret) {
-                       dev_err(&pdev->dev,
-                               "Could not register DMA PCM: %d\n"
-                               "falling back to PIO mode\n", ret);
+               if (irq >= 0) {
                        ret = dw_pcm_register(pdev);
-                       if (ret) {
-                               dev_err(&pdev->dev,
-                                       "Could not register PIO PCM: %d\n",
+                       dev->use_pio = true;
+               } else {
+                       ret = devm_snd_dmaengine_pcm_register(&pdev->dev, NULL,
+                                       0);
+                       dev->use_pio = false;
+               }
+
+               if (ret) {
+                       dev_err(&pdev->dev, "could not register pcm: %d\n",
                                        ret);
-                               goto err_clk_disable;
-                       }
+                       goto err_clk_disable;
                }
        }