[PATCH] ASoC: dwc: Fix PIO mode initialization

From: Jose Abreu
Date: Tue Dec 13 2016 - 06:03:49 EST


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@xxxxxxxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
---
sound/soc/dwc/designware_i2s.c | 25 +++++++++++--------------
1 file changed, 11 insertions(+), 14 deletions(-)

diff --git a/sound/soc/dwc/designware_i2s.c b/sound/soc/dwc/designware_i2s.c
index 2998954a1c74..bdf8398cbc81 100644
--- 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;
}
}

--
2.11.0