Re: [PATCH] dmaengine: ste_dma40: Preserve the LCPA I/O address space

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

On Sat, Oct 10, 2026 at 12:58:53AM +0200, Linus Walleij wrote:
> The LCPA area is mapped with devm_ioremap(), but lcpa_base and the
> per-channel lcpa pointer lack __iomem annotations. This loses the I/O
> address space and makes sparse warn when d40_current_addr() assigns
> LCPA register addresses to its __iomem pointers.
>
> Annotate both pointers and the LCPA argument of d40_log_lli_lcpa_write()
> to preserve the I/O address space from the mapping to the register
> accessors. This also fixes the existing LCPA read and write warnings
> without changing the generated code.
>
> Fixes: c80edceff29e ("dmaengine: ste_dma40: Fix cyclic transfer residue")
> Reported-by: kernel test robot <lkp@intel.com>
> Closes: https://lore.kernel.org/oe-kbuild-all/202610090216.pjMRxhRL-lkp@intel.com/
> Assisted-by: LLM
> Signed-off-by: Linus Walleij <linusw@kernel.org>
> ---

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

>  drivers/dma/ste_dma40.c    | 4 ++--
>  drivers/dma/ste_dma40_ll.c | 8 ++++----
>  drivers/dma/ste_dma40_ll.h | 2 +-
>  3 files changed, 7 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/dma/ste_dma40.c b/drivers/dma/ste_dma40.c
> index d3cc2c512ccf..74dd4cbdc3c0 100644
> --- a/drivers/dma/ste_dma40.c
> +++ b/drivers/dma/ste_dma40.c
> @@ -509,7 +509,7 @@ struct d40_chan {
>  	u32				 src_def_cfg;
>  	u32				 dst_def_cfg;
>  	struct d40_def_lcsp		 log_def;
> -	struct d40_log_lli_full		*lcpa;
> +	struct d40_log_lli_full __iomem	*lcpa;
>  	/* Runtime reconfiguration */
>  	dma_addr_t			runtime_addr;
>  	enum dma_transfer_direction	runtime_direction;
> @@ -617,7 +617,7 @@ struct d40_base {
>  	/* Physical half channels */
>  	struct d40_phy_res		 *phy_res;
>  	struct d40_lcla_pool		  lcla_pool;
> -	void				 *lcpa_base;
> +	void __iomem			 *lcpa_base;
>  	dma_addr_t			  phy_lcpa;
>  	resource_size_t			  lcpa_size;
>  	struct kmem_cache		 *desc_slab;
> diff --git a/drivers/dma/ste_dma40_ll.c b/drivers/dma/ste_dma40_ll.c
> index 4c489b126cb2..3be7f5b1abb0 100644
> --- a/drivers/dma/ste_dma40_ll.c
> +++ b/drivers/dma/ste_dma40_ll.c
> @@ -333,10 +333,10 @@ static void d40_log_lli_link(struct d40_log_lli *lli_dst,
>  		(dlos << D40_MEM_LCSP1_SLOS_POS);
>  }
>
> -void d40_log_lli_lcpa_write(struct d40_log_lli_full *lcpa,
> -			   struct d40_log_lli *lli_dst,
> -			   struct d40_log_lli *lli_src,
> -			   int next, unsigned int flags)
> +void d40_log_lli_lcpa_write(struct d40_log_lli_full __iomem *lcpa,
> +			    struct d40_log_lli *lli_dst,
> +			    struct d40_log_lli *lli_src,
> +			    int next, unsigned int flags)
>  {
>  	d40_log_lli_link(lli_dst, lli_src, next, flags);
>
> diff --git a/drivers/dma/ste_dma40_ll.h b/drivers/dma/ste_dma40_ll.h
> index 55090cb31057..ca9d07649361 100644
> --- a/drivers/dma/ste_dma40_ll.h
> +++ b/drivers/dma/ste_dma40_ll.h
> @@ -455,7 +455,7 @@ int d40_log_sg_to_lli(struct scatterlist *sg,
>  		      u32 lcsp13, /* src or dst*/
>  		      u32 data_width1, u32 data_width2);
>
> -void d40_log_lli_lcpa_write(struct d40_log_lli_full *lcpa,
> +void d40_log_lli_lcpa_write(struct d40_log_lli_full __iomem *lcpa,
>  			    struct d40_log_lli *lli_dst,
>  			    struct d40_log_lli *lli_src,
>  			    int next, unsigned int flags);
>
> ---
> base-commit: 511afae96d89847f753fcab6b3a597f0281be9d5
> change-id: 20261010-dma40-smatch-fix-42fce06d4f25
>
> Best regards,
> --
> Linus Walleij <linusw@kernel.org>
>