Re: [PATCH v8 07/15] drm/imx: dc: Add PRG support

[Laurentiu Palcu <laurentiu.palcu@oss.nxp.com>]

On Fri, Oct 30, 2026 at 05:54:31PM +0800, Liu Ying wrote:
> Display Prefetch Resolve Gasket(PRG) is a part of a FetchUnit's
> prefetch engine.  It sits between a Display Prefetch Resolve
> Channel(DPRC) and a FetchUnit.  Add a platform driver to support
> the PRG.
> 
> Reviewed-by: Frank Li <Frank.Li@nxp.com>
> Acked-by: Maxime Ripard <mripard@kernel.org>
> Signed-off-by: Liu Ying <victor.liu@nxp.com>
> ---
> v8:
> - Fix dc_prg_burst_size_fixup() to avoid overflowing signed integer 1.
>   (Sashiko AI bot)
> - Check device_link_add()'s return value and bail out if needed.
>   (Sashiko AI bot)
> - Drop unused header files.  (Laurentiu)
> 
> v7:
> - Collect Maxime's A-b tag.
> - Return 128B burst size from dc_prg_burst_size_fixup() when baddr == 0.
>   This avoids undefined behavior of __ffs(0).  (Sashiko AI bot)
> - Initialize and declare prg_node at the same time.  (Sashiko AI bot)
> - Add device link between PRG's consumer and PRG.  (Sashiko AI bot)
> 
> v6:
> - Include "dc-drv.h" to avoid build warning with C=1.
> - Fix PRG BYPASS programming.
> 
> v4:
> - Sort bits and bitfields in descending order for register PRG_CTRL.
> 
> v2:
> - Manage clocks with bulk interfaces.  (Frank)
> - Collect Frank's R-b tag.
> ---
>  drivers/gpu/drm/imx/dc/Makefile |   2 +-
>  drivers/gpu/drm/imx/dc/dc-drv.c |   1 +
>  drivers/gpu/drm/imx/dc/dc-drv.h |   1 +
>  drivers/gpu/drm/imx/dc/dc-prg.c | 318 ++++++++++++++++++++++++++++++++++++++++
>  drivers/gpu/drm/imx/dc/dc-prg.h |  35 +++++
>  5 files changed, 356 insertions(+), 1 deletion(-)
>

[...]

> diff --git a/drivers/gpu/drm/imx/dc/dc-prg.c b/drivers/gpu/drm/imx/dc/dc-prg.c
> new file mode 100644
> index 000000000000..46108f7e09af
> --- /dev/null
> +++ b/drivers/gpu/drm/imx/dc/dc-prg.c

[...]

> +
> +bool dc_prg_stride_supported(struct dc_prg *prg,

I searched all commits and this function is never touched again. So, you could
safely get rid of 'prg' argument since it's never used.

Otherwise:
Reviewed-by: Laurentiu Palcu <laurentiu.palcu@oss.nxp.com>

> +			     unsigned int stride, dma_addr_t baddr)
> +{
> +	unsigned int burst_size;
> +
> +	burst_size = dc_prg_burst_size_fixup(baddr);
> +
> +	stride = dc_prg_stride_fixup(stride, burst_size);
> +
> +	if (stride > DPU_PRG_MAX_STRIDE)
> +		return false;
> +
> +	return true;
> +}

[...]

-- 
Thanks,
Laurentiu