linux-kernel - [PATCH 3/3] ASoC: apple: mca: Improve handling of unavailable DMA channels

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Date:   Fri, 24 Feb 2023 16:33:02 +0100
From:   Martin Povišer <povik+lin@...ebit.org>
To:     Martin Povišer <povik+lin@...ebit.org>,
        Liam Girdwood <lgirdwood@...il.com>,
        Mark Brown <broonie@...nel.org>,
        Jaroslav Kysela <perex@...ex.cz>, Takashi Iwai <tiwai@...e.com>
Cc:     asahi@...ts.linux.dev, alsa-devel@...a-project.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH 3/3] ASoC: apple: mca: Improve handling of unavailable DMA channels

When we fail to obtain a DMA channel, don't return a blanket -EINVAL,
instead return the original error code if there's one. This makes
deferring work as it should. Also don't print an error message for
-EPROBE_DEFER.

Fixes: 4ec8179c212f ("ASoC: apple: mca: Postpone requesting of DMA channels")
Signed-off-by: Martin Povišer <povik+lin@...ebit.org>
---
 sound/soc/apple/mca.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/sound/soc/apple/mca.c b/sound/soc/apple/mca.c
index aea08c7b2ee8..64750db9b963 100644
--- a/sound/soc/apple/mca.c
+++ b/sound/soc/apple/mca.c
@@ -950,10 +950,17 @@ static int mca_pcm_new(struct snd_soc_component *component,
 		chan = mca_request_dma_channel(cl, i);
 
 		if (IS_ERR_OR_NULL(chan)) {
+			mca_pcm_free(component, rtd->pcm);
+
+			if (chan && PTR_ERR(chan) == -EPROBE_DEFER)
+				return PTR_ERR(chan);
+
 			dev_err(component->dev, "unable to obtain DMA channel (stream %d cluster %d): %pe\n",
 				i, cl->no, chan);
-			mca_pcm_free(component, rtd->pcm);
-			return -EINVAL;
+
+			if (!chan)
+				return -EINVAL;
+			return PTR_ERR(chan);
 		}
 
 		cl->dma_chans[i] = chan;
-- 
2.33.0