Re: [PATCH] ASoC: qcom: lpass-cpu: use DAI table index for playback constraints

[Srinivas Kandagatla <srinivas.kandagatla@oss.qualcomm.com>]

On 9/20/26 3:58 PM, Zimeng Li wrote:
> The DAI ID is a hardware port ID and is not necessarily the index of
> the corresponding entry in variant->dai_driver.
> 
> When configuring a DAI with LPAIF_I2SCTL_MODE_QUAD01, the probe code
> currently uses dai_id to index variant->dai_driver. This is incorrect
> for platforms where DAI IDs are sparse. For example, the IPQ806x MI2S
> DAI has ID 4 while it is the only entry in the DAI driver table, so
> the current code accesses dai_driver[4] instead of the DAI being
> processed.

This looks like a bug, however the code has been written in assumption
that the dai_drive.

That also raises the question that was this patch actually tested on any
hardware?

> 
> Use the loop index i when updating the current DAI's playback channel
> constraints, while retaining dai_id for indexing the hardware-port
> specific playback SD-line mode array.
> 
> This fixes the incorrect DAI table access for platforms where the DAI
> ID does not match its position in the driver table.
> 
> Fixes: c223f41c1a52 ("ASoC: qcom: Add four speaker support on MI2S secondary")

Cc Stable ?

> Signed-off-by: Zimeng Li <me@lizi.moe>
> Assisted-by: LLM
Can you please add the actual model name as others do.

> ---
> Compile-tested with LLVM for ARM using multi_v7_defconfig with
> CONFIG_SND_SOC_STORM=m. The lpass-cpu.o, lpass-ipq806x.o and
> lpass-platform.o targets built successfully. Not hardware-tested;
> the IPQ806x example is based on static analysis, not a reproduced crash.
> 
>  sound/soc/qcom/lpass-cpu.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/sound/soc/qcom/lpass-cpu.c b/sound/soc/qcom/lpass-cpu.c
> index 242bc16da..079177a6d 100644
> --- a/sound/soc/qcom/lpass-cpu.c
> +++ b/sound/soc/qcom/lpass-cpu.c
> @@ -1234,8 +1234,8 @@ int asoc_qcom_lpass_cpu_platform_probe(struct platform_device *pdev)
>  		}
>  		if (drvdata->mi2s_playback_sd_mode[dai_id] ==
>  			LPAIF_I2SCTL_MODE_QUAD01) {
> -			variant->dai_driver[dai_id].playback.channels_min = 4;
> -			variant->dai_driver[dai_id].playback.channels_max = 4;
> +			variant->dai_driver[i].playback.channels_min = 4;
> +			variant->dai_driver[i].playback.channels_max = 4;
>  		}
>  	}
>  
> 
> base-commit: 0ed6f7f62318a581fe9698f8a4e98c7ca01160e4