RE: [PATCH 2/3] media: nxp: imx8-isi: Keep the default value for BLANK_PXL field

[G.N. Zhou (OSS)]

Hi Laurent,

> -----Original Message-----
> From: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> Sent: Monday, October 27, 2025 6:12 AM
> To: Frank Li <frank.li@xxxxxxx>
> Cc: G.N. Zhou (OSS) <guoniu.zhou@xxxxxxxxxxx>; Mauro Carvalho Chehab
> <mchehab@xxxxxxxxxx>; Rob Herring <robh@xxxxxxxxxx>; Krzysztof Kozlowski
> <krzk+dt@xxxxxxxxxx>; Conor Dooley <conor+dt@xxxxxxxxxx>; Shawn Guo
> <shawnguo@xxxxxxxxxx>; Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>;
> Pengutronix Kernel Team <kernel@xxxxxxxxxxxxxx>; Fabio Estevam
> <festevam@xxxxxxxxx>; linux-media@xxxxxxxxxxxxxxx;
> devicetree@xxxxxxxxxxxxxxx; imx@xxxxxxxxxxxxxxx; linux-arm-
> kernel@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; G.N. Zhou
> <guoniu.zhou@xxxxxxx>
> Subject: Re: [PATCH 2/3] media: nxp: imx8-isi: Keep the default value for
> BLANK_PXL field
> 
> On Fri, Oct 24, 2025 at 09:41:50AM -0400, Frank Li wrote:
> > On Fri, Oct 24, 2025 at 05:46:53PM +0800, Guoniu Zhou wrote:
> > > From: Guoniu Zhou <guoniu.zhou@xxxxxxx>
> > >
> > > The field provides the value of the blank pixel to be inserted in
> > > the
> >
> > The field BLANK_PXL provides
> >
> > > image in case an overflow error occurs in the output buffers of the
> > > channel. Its default value is 0xff, so no need to set again.
> > >
> > > Besides, the field only exist in i.MX8QM/XP ISI version. Other
> > > versions like mscale series, remove the field since it won't send
> > > data to AXI bus
> 
> What's the mscale series ? Is that i.MX 8M ?

Yes, will update the commit log to make it clear. Thanks for your review.

> 
> > > when overflow error occurs and set the field as reserved. i.MX9
> > > series
> >
> > mark BLANK_PXL as reserved. i.MX9 series use it for other purposes.
> >
> > Reviewed-by: Frank Li <Frank.Li@xxxxxxx>
> >
> > > use the field as other purposes.
> > >
> > > Signed-off-by: Guoniu Zhou <guoniu.zhou@xxxxxxx>
> 
> Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> 
> > > ---
> > >  drivers/media/platform/nxp/imx8-isi/imx8-isi-hw.c | 6 ++----
> > >  1 file changed, 2 insertions(+), 4 deletions(-)
> > >
> > > diff --git a/drivers/media/platform/nxp/imx8-isi/imx8-isi-hw.c
> > > b/drivers/media/platform/nxp/imx8-isi/imx8-isi-hw.c
> > > index
> > >
> 9225a7ac1c3ee7e42e64983982eb4b6c27e356fe..0187d4ab97e8e28fca9013f6
> 86
> > > 4a094e08f2c570 100644
> > > --- a/drivers/media/platform/nxp/imx8-isi/imx8-isi-hw.c
> > > +++ b/drivers/media/platform/nxp/imx8-isi/imx8-isi-hw.c
> > > @@ -309,8 +309,8 @@ static void mxc_isi_channel_set_control(struct
> > > mxc_isi_pipe *pipe,
> > >
> > >  	val = mxc_isi_read(pipe, CHNL_CTRL);
> > >  	val &= ~(CHNL_CTRL_CHNL_BYPASS | CHNL_CTRL_CHAIN_BUF_MASK
> |
> > > -		 CHNL_CTRL_BLANK_PXL_MASK |
> CHNL_CTRL_SRC_TYPE_MASK |
> > > -		 CHNL_CTRL_MIPI_VC_ID_MASK |
> CHNL_CTRL_SRC_INPUT_MASK);
> > > +		 CHNL_CTRL_SRC_TYPE_MASK |
> CHNL_CTRL_MIPI_VC_ID_MASK |
> > > +		 CHNL_CTRL_SRC_INPUT_MASK);
> > >
> > >  	/*
> > >  	 * If no scaling or color space conversion is needed, bypass the
> > > @@ -323,8 +323,6 @@ static void mxc_isi_channel_set_control(struct
> mxc_isi_pipe *pipe,
> > >  	if (pipe->chained)
> > >  		val |=
> CHNL_CTRL_CHAIN_BUF(CHNL_CTRL_CHAIN_BUF_2_CHAIN);
> > >
> > > -	val |= CHNL_CTRL_BLANK_PXL(0xff);
> > > -
> > >  	/* Input source (including VC configuration for CSI-2) */
> > >  	if (input == MXC_ISI_INPUT_MEM) {
> > >  		/*
> 
> --
> Regards,
> 
> Laurent Pinchart