Re: [PATCH 7/9] ALSA: pcm_dmaengine: Use dma_slave_caps bus width helpers

[Frank Li <Frank.li@oss.nxp.com>]

On Thu, Jul 30, 2026 at 03:23:14PM +0100, Nuno Sá via B4 Relay wrote:
> [You don't often get email from devnull+nuno.sa.analog.com@kernel.org. Learn why this is important at https://aka.ms/LearnAboutSenderIdentification ]
>
> From: Nuno Sá <nuno.sa@analog.com>
>
> Use the dma_slave_caps bus width helpers instead of reading the legacy
> src_addr_widths and dst_addr_widths masks directly.
>
> Keep the existing default assumption of 1, 2 and 4 byte widths when the
> DMA channel does not report slave capabilities.
>
> Signed-off-by: Nuno Sá <nuno.sa@analog.com>
> ---

Reviewed-by: Frank Li <Frank.Li@nxp.com>

>  sound/core/pcm_dmaengine.c | 14 ++++++++------
>  1 file changed, 8 insertions(+), 6 deletions(-)
>
> diff --git a/sound/core/pcm_dmaengine.c b/sound/core/pcm_dmaengine.c
> index 1306b04be171..37468f4643bc 100644
> --- a/sound/core/pcm_dmaengine.c
> +++ b/sound/core/pcm_dmaengine.c
> @@ -409,15 +409,17 @@ int snd_dmaengine_pcm_refine_runtime_hwparams(
>         struct dma_chan *chan)
>  {
>         struct dma_slave_caps dma_caps;
> -       u32 addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
> -                         BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
> -                         BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
> +       DECLARE_DMA_BUS_WIDTHS(bus_widths) = {};
>         snd_pcm_format_t i;
>         int ret = 0;
>
>         if (!hw || !chan || !dma_data)
>                 return -EINVAL;
>
> +       __set_bit(DMA_SLAVE_BUSWIDTH_1_BYTE, bus_widths);
> +       __set_bit(DMA_SLAVE_BUSWIDTH_2_BYTES, bus_widths);
> +       __set_bit(DMA_SLAVE_BUSWIDTH_4_BYTES, bus_widths);
> +
>         ret = dma_get_slave_caps(chan, &dma_caps);
>         if (ret == 0) {
>                 if (dma_caps.cmd_pause && dma_caps.cmd_resume)
> @@ -426,9 +428,9 @@ int snd_dmaengine_pcm_refine_runtime_hwparams(
>                         hw->info |= SNDRV_PCM_INFO_BATCH;
>
>                 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
> -                       addr_widths = dma_caps.dst_addr_widths;
> +                       dma_slave_caps_copy_dst_widths(&dma_caps, bus_widths);
>                 else
> -                       addr_widths = dma_caps.src_addr_widths;
> +                       dma_slave_caps_copy_src_widths(&dma_caps, bus_widths);
>         }
>
>         /*
> @@ -460,7 +462,7 @@ int snd_dmaengine_pcm_refine_runtime_hwparams(
>                         case 24:
>                         case 32:
>                         case 64:
> -                               if (addr_widths & (1 << (bits / 8)))
> +                               if (test_bit(bits / 8, bus_widths))
>                                         hw->formats |= pcm_format_to_bits(i);
>                                 break;
>                         default:
>
> --
> 2.55.0
>
>