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In-Reply-To: <20200330120745.GA3213219@oden.dyn.berto.se>
From:   "Lad, Prabhakar" <prabhakar.csengg@gmail.com>
Date:   Mon, 6 Apr 2020 18:20:33 +0100
Message-ID: <CA+V-a8vbTc0DZ15y0zZ97PH6khwQVxz=M-8_kgx1AiKkdg5QaA@mail.gmail.com>
Subject: Re: [PATCH v2 2/3] media: rcar-vin: Add support for
 MEDIA_BUS_FMT_SRGGB8_1X8 format
To:     Niklas <niklas.soderlund@ragnatech.se>
Cc:     Prabhakar Mahadev Lad <prabhakar.mahadev-lad.rj@bp.renesas.com>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        "linux-media@vger.kernel.org" <linux-media@vger.kernel.org>,
        "linux-renesas-soc@vger.kernel.org" 
        <linux-renesas-soc@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
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Sender: linux-kernel-owner@vger.kernel.org
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HI Niklas,

On Mon, Mar 30, 2020 at 1:07 PM Niklas <niklas.soderlund@ragnatech.se> wrote:
>
> Hi Lad,
>
> Thanks for your reply.
>
> On 2020-03-27 12:59:52 +0000, Lad, Prabhakar wrote:
> > Hi Niklas,
> >
> > On Thu, Mar 19, 2020 at 3:03 PM Niklas <niklas.soderlund@ragnatech.se> wrote:
> > >
> > > Hi Prabhakar,
> > >
> > > Thanks for the sample files, sorry I did not have time before now to
> > > look at them. After doing so I believe I know what is wrong, see bellow.
> > >
> > > On 2020-03-15 19:35:58 +0000, Lad, Prabhakar wrote:
> > > > Hi Niklas,
> > > >
> > > > On Tue, Mar 10, 2020 at 2:06 PM Niklas <niklas.soderlund@ragnatech.se> wrote:
> > > > >
> > > > > Hi Lad,
> > > > >
> > > > > On 2020-03-10 13:42:20 +0000, Prabhakar Mahadev Lad wrote:
> > > > > > Hi Niklas,
> > > > > >
> > > > > > Thank for the review.
> > > > > >
> > > > > > > -----Original Message-----
> > > > > > > From: Niklas <niklas.soderlund@ragnatech.se>
> > > > > > > Sent: 10 March 2020 12:46
> > > > > > > To: Prabhakar Mahadev Lad <prabhakar.mahadev-lad.rj@bp.renesas.com>
> > > > > > > Cc: Mauro Carvalho Chehab <mchehab@kernel.org>; linux-
> > > > > > > media@vger.kernel.org; linux-renesas-soc@vger.kernel.org; linux-
> > > > > > > kernel@vger.kernel.org; Lad Prabhakar <prabhakar.csengg@gmail.com>
> > > > > > > Subject: Re: [PATCH v2 2/3] media: rcar-vin: Add support for
> > > > > > > MEDIA_BUS_FMT_SRGGB8_1X8 format
> > > > > > >
> > > > > > > Hi Lad,
> > > > > > >
> > > > > > > Thanks for your work.
> > > > > > >
> > > > > > > On 2020-03-10 11:06:03 +0000, Lad Prabhakar wrote:
> > > > > > > > Add support for MEDIA_BUS_FMT_SRGGB8_1X8 format in rcar-vin by
> > > > > > > setting
> > > > > > > > format type to RAW8 in VNMC register and appropriately setting the
> > > > > > > > bpp, bytesperline to enable V4L2_PIX_FMT_SRGGB8.
> > > > > > > >
> > > > > > > > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-
> > > > > > > lad.rj@bp.renesas.com>
> > > > > > > > ---
> > > > > > > >  drivers/media/platform/rcar-vin/rcar-core.c |  1 +
> > > > > > > > drivers/media/platform/rcar-vin/rcar-dma.c  |  9 ++++++++-
> > > > > > > > drivers/media/platform/rcar-vin/rcar-v4l2.c | 13 ++++++++++++-
> > > > > > > >  3 files changed, 21 insertions(+), 2 deletions(-)
> > > > > > > >
> > > > > > > > diff --git a/drivers/media/platform/rcar-vin/rcar-core.c
> > > > > > > > b/drivers/media/platform/rcar-vin/rcar-core.c
> > > > > > > > index 7440c89..76daf2f 100644
> > > > > > > > --- a/drivers/media/platform/rcar-vin/rcar-core.c
> > > > > > > > +++ b/drivers/media/platform/rcar-vin/rcar-core.c
> > > > > > > > @@ -469,6 +469,7 @@ static int rvin_parallel_subdevice_attach(struct
> > > > > > > rvin_dev *vin,
> > > > > > > >  case MEDIA_BUS_FMT_UYVY8_2X8:
> > > > > > > >  case MEDIA_BUS_FMT_UYVY10_2X10:
> > > > > > > >  case MEDIA_BUS_FMT_RGB888_1X24:
> > > > > > > > +case MEDIA_BUS_FMT_SRGGB8_1X8:
> > > > > > > >  vin->mbus_code = code.code;
> > > > > > > >  vin_dbg(vin, "Found media bus format for %s: %d\n",
> > > > > > > >  subdev->name, vin->mbus_code);
> > > > > > > > diff --git a/drivers/media/platform/rcar-vin/rcar-dma.c
> > > > > > > > b/drivers/media/platform/rcar-vin/rcar-dma.c
> > > > > > > > index 1a30cd0..1c1fafa 100644
> > > > > > > > --- a/drivers/media/platform/rcar-vin/rcar-dma.c
> > > > > > > > +++ b/drivers/media/platform/rcar-vin/rcar-dma.c
> > > > > > > > @@ -85,6 +85,7 @@
> > > > > > > >  #define VNMC_INF_YUV8_BT601(1 << 16)
> > > > > > > >  #define VNMC_INF_YUV10_BT656(2 << 16)
> > > > > > > >  #define VNMC_INF_YUV10_BT601(3 << 16)
> > > > > > > > +#define VNMC_INF_RAW8(4 << 16)
> > > > > > > >  #define VNMC_INF_YUV16(5 << 16)
> > > > > > > >  #define VNMC_INF_RGB888(6 << 16)
> > > > > > > >  #define VNMC_VUP(1 << 10)
> > > > > > > > @@ -587,7 +588,6 @@ void rvin_crop_scale_comp(struct rvin_dev *vin)
> > > > > > > >  rvin_write(vin, vin->crop.top, VNSLPRC_REG);
> > > > > > > >  rvin_write(vin, vin->crop.top + vin->crop.height - 1, VNELPRC_REG);
> > > > > > > >
> > > > > > > > -
> > > > > > > >  /* TODO: Add support for the UDS scaler. */
> > > > > > > >  if (vin->info->model != RCAR_GEN3)
> > > > > > > >  rvin_crop_scale_comp_gen2(vin);
> > > > > > > > @@ -676,6 +676,9 @@ static int rvin_setup(struct rvin_dev *vin)
> > > > > > > >
> > > > > > > >  input_is_yuv = true;
> > > > > > > >  break;
> > > > > > > > +case MEDIA_BUS_FMT_SRGGB8_1X8:
> > > > > > > > +vnmc |= VNMC_INF_RAW8;
> > > > > > > > +break;
> > > > > > > >  default:
> > > > > > > >  break;
> > > > > > > >  }
> > > > > > > > @@ -737,6 +740,9 @@ static int rvin_setup(struct rvin_dev *vin)
> > > > > > > >  case V4L2_PIX_FMT_ABGR32:
> > > > > > > >  dmr = VNDMR_A8BIT(vin->alpha) | VNDMR_EXRGB |
> > > > > > > VNDMR_DTMD_ARGB;
> > > > > > > >  break;
> > > > > > > > +case V4L2_PIX_FMT_SRGGB8:
> > > > > > > > +dmr = 0;
> > > > > > > > +break;
> > > > > > > >  default:
> > > > > > > >  vin_err(vin, "Invalid pixelformat (0x%x)\n",
> > > > > > > >  vin->format.pixelformat);
> > > > > > > > @@ -1110,6 +1116,7 @@ static int rvin_mc_validate_format(struct
> > > > > > > rvin_dev *vin, struct v4l2_subdev *sd,
> > > > > > > >  case MEDIA_BUS_FMT_UYVY8_2X8:
> > > > > > > >  case MEDIA_BUS_FMT_UYVY10_2X10:
> > > > > > > >  case MEDIA_BUS_FMT_RGB888_1X24:
> > > > > > > > +case MEDIA_BUS_FMT_SRGGB8_1X8:
> > > > > > > >  vin->mbus_code = fmt.format.code;
> > > > > > > >  break;
> > > > > > > >  default:
> > > > > > > > diff --git a/drivers/media/platform/rcar-vin/rcar-v4l2.c
> > > > > > > > b/drivers/media/platform/rcar-vin/rcar-v4l2.c
> > > > > > > > index 5151a3c..4698099 100644
> > > > > > > > --- a/drivers/media/platform/rcar-vin/rcar-v4l2.c
> > > > > > > > +++ b/drivers/media/platform/rcar-vin/rcar-v4l2.c
> > > > > > > > @@ -66,6 +66,10 @@ static const struct rvin_video_format rvin_formats[]
> > > > > > > = {
> > > > > > > >  .fourcc= V4L2_PIX_FMT_ABGR32,
> > > > > > > >  .bpp= 4,
> > > > > > > >  },
> > > > > > > > +{
> > > > > > > > +.fourcc= V4L2_PIX_FMT_SRGGB8,
> > > > > > > > +.bpp= 2,
> > > > > > >
> > > > > > > This does not look right, is not bytes-per-pixel 1 for a SRGGB8?
> > > > > > >
> > > > > > I guessed the bpp's were picked from VnIS table as I result I did the same.
> > > > > >
> > > > > > > > +},
> > > > > > > >  };
> > > > > > > >
> > > > > > > >  const struct rvin_video_format *rvin_format_from_pixel(struct
> > > > > > > > rvin_dev *vin, @@ -102,6 +106,7 @@ static u32
> > > > > > > > rvin_format_bytesperline(struct rvin_dev *vin,  {
> > > > > > > >  const struct rvin_video_format *fmt;
> > > > > > > >  u32 align;
> > > > > > > > +u8 div;
> > > > > > > >
> > > > > > > >  fmt = rvin_format_from_pixel(vin, pix->pixelformat);
> > > > > > > >
> > > > > > > > @@ -112,16 +117,22 @@ static u32 rvin_format_bytesperline(struct
> > > > > > > rvin_dev *vin,
> > > > > > > >  case V4L2_PIX_FMT_NV12:
> > > > > > > >  case V4L2_PIX_FMT_NV16:
> > > > > > > >  align = 0x20;
> > > > > > > > +div = 1;
> > > > > > > > +break;
> > > > > > > > +case V4L2_PIX_FMT_SRGGB8:
> > > > > > > > +align = 0x10;
> > > > > > > > +div = 2;
> > > > > > >
> > > > > > > Yes this does not look right at all, I think you should set bpp to 1 and drop the
> > > > > > > div handling here.
> > > > > > >
> > > > > > If I set bpp as 1 and drop the div VNIS_REG will be wrongly configured in
> > > > > > rvin_crop_scale_comp() and the image captured will be wrong.
> > > > > >
> > > > > > For example for 640x480:
> > > > > >
> > > > > > With the current patch bpp = 2:
> > > > > > bytesperline = 640
> > > > >
> > > > > This is wrong, if we have a line of 640 pixels and 2 bytes per pixel
> > > > > then bytesperline must be at least 1280 bytes right?
> > > > >
> > > > > > image size = 307200
> > > > > > stride = 320
> > > > >
> > > > > But this is incorrect, the VNIS_REG shall be at least the number of
> > > > > pixels in a line (EPPrC - SPPrC -> 640 - 0 = 640). Then we need to align
> > > > > it to the pixel unit (16, 32, 64, 128) depending on the output pixel
> > > > > format.
> > > > >
> > > > > This usually result in a stride that is larger then the line length.
> > > > > Thus you need a test application that knows the difference between width
> > > > > * bpp and bytesperline. I use qv4l2 without opengl support when I do quick
> > > > > tests and it does not support this hence I get a incorrect visual view
> > > > > of the stream when testing.
> > > > >
> > > > > How does the image capture fail with bpp = 1?
> > > > >
> > > > Attached is the captured bayer images 640x480 with bpp set to 1, for
> > > > file1bppstridediv1.raw
> > > > VNIS_REG stride set to 640 and for file file1bppstridediv2.raw
> > > > VNIS_REF stride  set to (640 * 1) / 2.
> > > > When the file1bppstridediv1.raw image is converted to png colors are incorrect
> > > > but whereas file1bppstridediv2.raw converted to png the picture is clear.
> > > >
> > > > Also while doing a loop-back to fbdevsink with the below pipeline:
> > > > gst-launch-1.0 -vvv v4l2src device=/dev/video0 io-mode=dmabuf ! 'video/x-bayer,
> > > > format=rggb,width=640,height=480,framerate=30/1' ! queue ! bayer2rgb !
> > > > videoconvert
> > > > ! fbdevsink sync=false
> > > >
> > > > width = 640 height = 480 bpp = 1, bytesperline = 640 stride = 320
> > > > works correctly
> > > > width = 640 height = 480 bpp = 1, bytesperline = 640 stride = 640
> > > > image displayed is incorrect
> > >
> > > It's very unlogical to have a stride that is less then the width, which
> > > got me interested why the second one gave you better results. I wrote a
> > > small python hack which converts the raw SRGGB8 to PNG without any
> > > debyaer, just rows of RGRGRG and BGBGBG.
> > >
> > Finally I have some information from the hardware team, the VIN process RAW8
> > in 2 pixel units as a result the stride for RAW8 needs to be
> > configured as bytesperline/2.
>
> Interesting, that is not how I have interpreted the datasheet. But
> rereading it now after our discussion I see how it could be so. I will
> dig into it during the week and see if I get make it all click in my
> head. Thanks for pointing this out.
>
Did you manage to get the required information on this ?

Cheers,
--Prabhakar