Re: [PATCH 1/3] dma: fsl_raid: fix endianness of in-memory descriptor stores

[Frank Li]

On Tue, Jul 14, 2026 at 04:38:53PM -0700, Rosen Penev wrote:
> The descriptor structs (fsl_re_cmpnd_frame / fsl_re_hw_desc) are
> in-memory but their fields are __be32, because the structures are handed
> to the device as big-endian. The driver stored CPU-endian u32 values
> into them directly, which is both wrong (the engine would see
> byte-swapped lengths/addresses) and flagged by sparse as a base-type
> mismatch.
>
> Wrap those stores in cpu_to_be32() so the values are little->big
> converted. The final-frame bit is now passed as the "final" argument of
> fill_cfd_frame() (as fsl_re_prep_dma_memcpy already did) and set in CPU
> order before the single cpu_to_be32() store, replacing the previous
> read-modify-write of the __be32 efrl32 field.

Can you split two patches, one add cpu_le_be32(), other change to call
fill_cfd_frame()

Frank
>
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> Fixes: https://lore.kernel.org/oe-kbuild-all/202008111749.yy85rFMD%25lkp@xxxxxxxxx/
> Assisted-by: opencode:hy3-free
> Signed-off-by: Rosen Penev <rosenp@xxxxxxxxx>
> ---
>  drivers/dma/fsl_raid.c | 29 +++++++++++++++--------------
>  1 file changed, 15 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/dma/fsl_raid.c b/drivers/dma/fsl_raid.c
> index 99945845d8b5..888f55b672a5 100644
> --- a/drivers/dma/fsl_raid.c
> +++ b/drivers/dma/fsl_raid.c
> @@ -242,9 +242,9 @@ static void fill_cfd_frame(struct fsl_re_cmpnd_frame *cf, u8 index,
>  	u32 efrl = length & FSL_RE_CF_LENGTH_MASK;
>
>  	efrl |= final << FSL_RE_CF_FINAL_SHIFT;
> -	cf[index].efrl32 = efrl;
> -	cf[index].addr_high = upper_32_bits(addr);
> -	cf[index].addr_low = lower_32_bits(addr);
> +	cf[index].efrl32 = cpu_to_be32(efrl);
> +	cf[index].addr_high = cpu_to_be32(upper_32_bits(addr));
> +	cf[index].addr_low = cpu_to_be32(lower_32_bits(addr));
>  }
>
>  static struct fsl_re_desc *fsl_re_init_desc(struct fsl_re_chan *re_chan,
> @@ -256,9 +256,10 @@ static struct fsl_re_desc *fsl_re_init_desc(struct fsl_re_chan *re_chan,
>  	dma_async_tx_descriptor_init(&desc->async_tx, &re_chan->chan);
>  	INIT_LIST_HEAD(&desc->node);
>
> -	desc->hwdesc.fmt32 = FSL_RE_FRAME_FORMAT << FSL_RE_HWDESC_FMT_SHIFT;
> -	desc->hwdesc.lbea32 = upper_32_bits(paddr);
> -	desc->hwdesc.addr_low = lower_32_bits(paddr);
> +	desc->hwdesc.fmt32 = cpu_to_be32(FSL_RE_FRAME_FORMAT <<
> +					  FSL_RE_HWDESC_FMT_SHIFT);
> +	desc->hwdesc.lbea32 = cpu_to_be32(upper_32_bits(paddr));
> +	desc->hwdesc.addr_low = cpu_to_be32(lower_32_bits(paddr));
>  	desc->cf_addr = cf;
>  	desc->cf_paddr = paddr;
>
> @@ -374,11 +375,11 @@ static struct dma_async_tx_descriptor *fsl_re_prep_dma_genq(
>  	for (i = 2, j = 0; j < save_src_cnt; i++, j++)
>  		fill_cfd_frame(cf, i, len, src[j], 0);
>
> +	/* Fill the last frame and mark it final */
>  	if (cont_q)
> -		fill_cfd_frame(cf, i++, len, dest, 0);
> -
> -	/* Setting the final bit in the last source buffer frame in CFD */
> -	cf[i - 1].efrl32 |= 1 << FSL_RE_CF_FINAL_SHIFT;
> +		fill_cfd_frame(cf, i, len, dest, 1);
> +	else
> +		fill_cfd_frame(cf, i - 1, len, src[j - 1], 1);
>
>  	return &desc->async_tx;
>  }
> @@ -504,16 +505,16 @@ static struct dma_async_tx_descriptor *fsl_re_prep_dma_pq(
>  			p[save_src_cnt + 2] = 1;
>  			fill_cfd_frame(cf, i++, len, dest[0], 0);
>  			fill_cfd_frame(cf, i++, len, dest[1], 0);
> -			fill_cfd_frame(cf, i++, len, dest[1], 0);
> +			fill_cfd_frame(cf, i++, len, dest[1], 1);
>  		} else {
>  			dev_err(re_chan->dev, "PQ tx continuation error!\n");
>  			return NULL;
>  		}
> +	} else {
> +		/* Mark the last source buffer frame final */
> +		fill_cfd_frame(cf, i - 1, len, src[j - 1], 1);
>  	}
>
> -	/* Setting the final bit in the last source buffer frame in CFD */
> -	cf[i - 1].efrl32 |= 1 << FSL_RE_CF_FINAL_SHIFT;
> -
>  	return &desc->async_tx;
>  }
>
> --
> 2.55.0
>