sound/soc/loongson/loongson_dma.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)
The "invalid position" error occurred when the DMA position descriptor
returned an invalid address value (e.g., pos = -1048838144). This happened
because the `bytes_to_frames()` function returns a signed value, but when
`addr < runtime->dma_addr`, the subtraction produces a negative result that
gets interpreted as a large unsigned integer in comparisons.
when the addr is abnormal, for example,the DMA controller is abnormal in
hardware,x=0 should not be a point(x == runtime->buffer_size),but a range,
which includes the addr address being less than runtime ->dma1-adr, and
the addr exceeding the DMA address range.the value of pos should not better
a negative,return 0, maybe better.
[ 32.834431][ 2] soc-audio soc-audio: invalid position: , pos = -1048838144
[ 32.845019][ 2] soc-audio soc-audio: invalid position: , pos = -1048838144
[ 32.855588][ 2] soc-audio soc-audio: invalid position: , pos = -1048838144
[ 32.866145][ 2] soc-audio soc-audio: invalid position: , pos = -1048838144
[ 32.995394][ 2] soc-audio soc-audio: invalid position: , pos = -1048838144
[ 33.006025][ 2] soc-audio soc-audio: invalid position: , pos = -1048838144
[ 33.016748][ 2] soc-audio soc-audio: invalid position: , pos = -1048838144
Signed-off-by: Li Jun <lijun01@kylinos.cn>
---
sound/soc/loongson/loongson_dma.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/sound/soc/loongson/loongson_dma.c b/sound/soc/loongson/loongson_dma.c
index a149b643175c..281bc991b110 100644
--- a/sound/soc/loongson/loongson_dma.c
+++ b/sound/soc/loongson/loongson_dma.c
@@ -199,6 +199,7 @@ loongson_pcm_pointer(struct snd_soc_component *component,
struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime = substream->runtime;
+ struct device *dev = substream->pcm->card->dev;
struct loongson_runtime_data *prtd = runtime->private_data;
struct loongson_dma_desc *desc;
snd_pcm_uframes_t x;
@@ -207,9 +208,16 @@ loongson_pcm_pointer(struct snd_soc_component *component,
desc = dma_desc_save(prtd);
addr = ((u64)desc->saddr_hi << 32) | desc->saddr;
- x = bytes_to_frames(runtime, addr - runtime->dma_addr);
- if (x == runtime->buffer_size)
+ if (addr < runtime->dma_addr ||
+ addr > runtime->dma_addr + runtime->dma_bytes) {
+ dev_warn(dev, "WARNING! dma_addr:0x%x\n", addr);
x = 0;
+ } else {
+ x = bytes_to_frames(runtime, addr - runtime->dma_addr);
+ if (x == runtime->buffer_size)
+ x = 0;
+ }
+
return x;
}
--
2.25.1
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