Re: [PATCH 2/2] media: rppx1: bls: read the raw pattern from the PRE2 acquisition module

[Jacopo Mondi]

Hi Niklas

On Mon, Aug 17, 2026 at 07:14:12PM +0200, Niklas Söderlund wrote:
> Hello Linmao,
>
> Thanks for your work.
>
> On 2026-08-17 18:45:29 +0800, Linmao Li wrote:
> > rppx1_bls_swap_regs() gets the Bayer pattern from the acquisition
> > module. The PRE1 path uses pre1.acq, but the PRE2 path mistakenly uses
> > pre2.bls. The BLS module does not store a Bayer pattern, so PRE2 would
> > read zero (RGGB) and map fixed black levels to the wrong colour
> > registers.
> >
> > PRE2 is not started or dispatched yet, so the bug is currently
> > latent. Read the pattern from pre2.acq, as the PRE1 path does.
> >
> > Fixes: 3f8a2a883655 ("media: rppx1: bls: Add support for black level compensation")
> > Signed-off-by: Linmao Li <lilinmao@xxxxxxxxxx>
> > ---
> >  drivers/media/platform/dreamchip/rppx1/rppx1_bls.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/media/platform/dreamchip/rppx1/rppx1_bls.c b/drivers/media/platform/dreamchip/rppx1/rppx1_bls.c
> > index 01a61db279bf7..71c5561457d52 100644
> > --- a/drivers/media/platform/dreamchip/rppx1/rppx1_bls.c
> > +++ b/drivers/media/platform/dreamchip/rppx1/rppx1_bls.c
> > @@ -70,7 +70,7 @@ rppx1_bls_swap_regs(struct rpp_module *mod, const u32 input[4], u32 output[4])
> >
> >  	/* Swap to pattern used in our path, PRE1 or PRE2. */
> >  	struct rpp_module *acq = mod == &mod->rpp->pre1.bls ?
> > -		&mod->rpp->pre1.acq : &mod->rpp->pre2.bls;
> > +		&mod->rpp->pre1.acq : &mod->rpp->pre2.acq;
>
> As pointed out elsewhere in this series, PRE2 is not enabled yet.
>

Isn't this however a bug worth fixing anyway ?

The raw_pattern is initialized for the 'acq' module, not the bls one

rppx1/rppx1_acq.c:             mod->info.acq.raw_pattern = RPP_BGGR;
rppx1/rppx1_acq.c:             mod->info.acq.raw_pattern = RPP_GBRG;
rppx1/rppx1_acq.c:             mod->info.acq.raw_pattern = RPP_GRBG;
rppx1/rppx1_acq.c:             mod->info.acq.raw_pattern = RPP_RGGB;


> >  	enum rpp_raw_pattern pattern = acq->info.acq.raw_pattern;
> >
> >  	for (unsigned int i = 0; i < 4; ++i)
> > --
> > 2.25.1
> >
>
> --
> Kind Regards,
> Niklas Söderlund