linux-kernel - Re: [PATCH v4 1/1] media: rkisp1: Fix filter mode register configuration

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Message-ID: <20260106034648.GP10026@pendragon.ideasonboard.com>
Date: Tue, 6 Jan 2026 05:46:48 +0200
From: Laurent Pinchart <laurent.pinchart@...asonboard.com>
To: Rui Wang <rui.wang@...asonboard.com>
Cc: linux-media@...r.kernel.org, dafna@...tmail.com, mchehab@...nel.org,
	heiko@...ech.de, linux-rockchip@...ts.infradead.org,
	linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
	libcamera-devel@...ts.libcamera.org
Subject: Re: [PATCH v4 1/1] media: rkisp1: Fix filter mode register
 configuration

Hi Rui,

Thank you for the patch.

On Mon, Jan 05, 2026 at 12:11:42PM -0500, Rui Wang wrote:
> The rkisp1_flt_config() function performs an initial direct write to
> RKISP1_CIF_ISP_FILT_MODE without including the RKISP1_CIF_ISP_FLT_ENA
> bit, which clears the filter enable bit in the hardware.
> 
> The subsequent read/modify/write sequence then reads back the register
> with the enable bit already cleared and cannot restore it, resulting in
> the filter being inadvertently disabled.
> 
> Remove the redundant direct write. The read/modify/write sequence alone
> correctly preserves the existing enable bit state while updating the
> DNR mode and filter configuration bits.
> 
> Signed-off-by: Rui Wang <rui.wang@...asonboard.com>

Reviewed-by: Laurent Pinchart <laurent.pinchart@...asonboard.com>

and pushed to CI in
https://gitlab.freedesktop.org/linux-media/users/pinchartl/-/pipelines/1578184.
If the pipeline succeeds I'll queue the patch for v6.20. Otherwise I'll
report the failure here.

> ---
>  
> Changelog since v1:
>  1. Update version number from v1 to v4 to clarify the confusing
> 
> Reviewed-by Stefan Klug and Kieran Bingham
>  from v1 are carried over (no function code changes).
> 
>  drivers/media/platform/rockchip/rkisp1/rkisp1-params.c | 6 ------
>  1 file changed, 6 deletions(-)
> 
> diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c b/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c
> index c9f88635224c..6442436a5e42 100644
> --- a/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c
> +++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c
> @@ -411,12 +411,6 @@ static void rkisp1_flt_config(struct rkisp1_params *params,
>  	rkisp1_write(params->rkisp1, RKISP1_CIF_ISP_FILT_LUM_WEIGHT,
>  		     arg->lum_weight);
>  
> -	rkisp1_write(params->rkisp1, RKISP1_CIF_ISP_FILT_MODE,
> -		     (arg->mode ? RKISP1_CIF_ISP_FLT_MODE_DNR : 0) |
> -		     RKISP1_CIF_ISP_FLT_CHROMA_V_MODE(arg->chr_v_mode) |
> -		     RKISP1_CIF_ISP_FLT_CHROMA_H_MODE(arg->chr_h_mode) |
> -		     RKISP1_CIF_ISP_FLT_GREEN_STAGE1(arg->grn_stage1));
> -
>  	/* avoid to override the old enable value */
>  	filt_mode = rkisp1_read(params->rkisp1, RKISP1_CIF_ISP_FILT_MODE);
>  	filt_mode &= RKISP1_CIF_ISP_FLT_ENA;

-- 
Regards,

Laurent Pinchart