Re: [PATCH v2 2/2] media: rppx1: Update shadowed registers

[Niklas Söderlund]

Hi Barnabás,

Thanks for your work.

On 2026-10-27 18:40:14 +0100, Barnabás Pőcze wrote:
> Certain registers are shadowed and changes to those must be explicly
> applied. Updating the shadowed registers after a frame is complete can
> be done by writing `RPPX1_RPP_HDR_UPD_REGS_GEN_CFG_UPD` to the
> `RPPX1_RPP_HDR_UPD_REG` register.
> 
> This is already done in `rppx1_start()`, but this auto-update feature
> is documented as "self reset at picture end". Therefore setting it
> at start will only auto-update the registers once, after the first
> frame.
> 
> For example, this causes that the LSC module cannot be toggled after
> the first frame. This behaviour can be tested by reading the first
> bit of `LSC_STATUS_REG`, which will show the same value after the
> first frame regardless of what was last written to `LSC_CTRL_REG`.
> 
> Fix this by unconditionall triggering an auto-update when a parameter
> buffer is processed in `rppx1_params()`.
> 
> Signed-off-by: Barnabás Pőcze <barnabas.pocze+renesas@xxxxxxxxxxxxxxxx>

Looks good.

Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>

> ---
>  drivers/media/platform/dreamchip/rppx1/rpp_params.c | 3 +++
>  drivers/media/platform/dreamchip/rppx1/rppx1.c      | 3 ---
>  2 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/media/platform/dreamchip/rppx1/rpp_params.c b/drivers/media/platform/dreamchip/rppx1/rpp_params.c
> index a75a27a8afd09..cbc9847ba5be6 100644
> --- a/drivers/media/platform/dreamchip/rppx1/rpp_params.c
> +++ b/drivers/media/platform/dreamchip/rppx1/rpp_params.c
> @@ -110,6 +110,9 @@ int rppx1_params(struct rppx1 *rpp, struct vb2_buffer *vb, size_t max_size,
>  		}
>  	}
>  
> +	/* Trigger update of shadowed registers after frame is done. */
> +	write(priv, RPPX1_RPP_HDR_UPD_REG, RPPX1_RPP_HDR_UPD_REGS_GEN_CFG_UPD);
> +
>  	return 0;
>  }
>  EXPORT_SYMBOL_GPL(rppx1_params);
> diff --git a/drivers/media/platform/dreamchip/rppx1/rppx1.c b/drivers/media/platform/dreamchip/rppx1/rppx1.c
> index c03dd061783a5..a3c923a57d922 100644
> --- a/drivers/media/platform/dreamchip/rppx1/rppx1.c
> +++ b/drivers/media/platform/dreamchip/rppx1/rppx1.c
> @@ -257,9 +257,6 @@ int rppx1_start(struct rppx1 *rpp,
>  	/* Immediate commit update for shadows. */
>  	rppx1_write(rpp, RPPX1_RPP_HDR_UPD_REG, RPPX1_RPP_HDR_UPD_REGS_CFG_UPD);
>  
> -	/* Then for operation update shadows with picture synchronization. */
> -	rppx1_write(rpp, RPPX1_RPP_HDR_UPD_REG, RPPX1_RPP_HDR_UPD_REGS_GEN_CFG_UPD);
> -
>  	/* Clear any pending interrupts. */
>  	rppx1_interrupt(rpp, NULL);
>  
> -- 
> 2.56.0
> 

-- 
Kind Regards,
Niklas Söderlund