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ASoC: soc-generic-dmaengine: Handle DMA channel request failures correctly

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Currently any dma_request_chan() failure other than -EPROBE_DEFER is
silently ignored, since a missing channel is expected for devices that
only support one DMA direction.

Improve the handling of these failures by:
- reporting failures when a configured DMA channel cannot be requested;
- failing probe if neither playback nor capture obtains a DMA channel,
  since the PCM device would be unusable.

Devices that legitimately support only one DMA direction continue to
work as before.

Signed-off-by: bui duc phuc <phucduc.bui@gmail.com>
Link: https://patch.msgid.link/20260720064131.75156-1-phucduc.bui@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
bui duc phuc
2026-07-20 13:41:31 +07:00
committed by Mark Brown
parent 14cdac7638
commit 9167f26047
1 changed files with 28 additions and 0 deletions
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28
sound/soc/soc-generic-dmaengine-pcm.c
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@@ -3,6 +3,7 @@
// Copyright (C) 2013, Analog Devices Inc.
// Author: Lars-Peter Clausen <lars@metafoo.de>
#include <linux/acpi.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/dmaengine.h>
@@ -395,6 +396,27 @@ static int dmaengine_pcm_request_chan_of(struct dmaengine_pcm *pcm,
*/
if (PTR_ERR(chan) == -EPROBE_DEFER)
return -EPROBE_DEFER;
bool has_fw_node = dev->of_node || is_acpi_device_node(dev->fwnode);
bool name_exists_in_fw = false;
if (has_fw_node)
name_exists_in_fw = device_property_match_string(dev,
"dma-names",
name) >= 0;
if (has_fw_node && name_exists_in_fw)
dev_warn(dev, "DTS/ACPI DMA channel '%s' request failed (%ld)\n",
name, PTR_ERR(chan));
if (has_fw_node && !name_exists_in_fw)
dev_warn(dev, "DTS/ACPI name '%s' not found, legacy failed (%ld)\n",
name, PTR_ERR(chan));
if (!has_fw_node)
dev_warn(dev, "Legacy DMA channel '%s' request failed (%ld)\n",
name, PTR_ERR(chan));
pcm->chan[i] = NULL;
} else {
pcm->chan[i] = chan;
@@ -406,6 +428,12 @@ static int dmaengine_pcm_request_chan_of(struct dmaengine_pcm *pcm,
if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
pcm->chan[1] = pcm->chan[0];
if (!pcm->chan[0] &&
!pcm->chan[1]) {
dev_err(dev, "no DMA channel found for either playback or capture\n");
return -ENODEV;
}
return 0;
}