Hi Kieran,
On Monday, 23 April 2018 11:59:04 EEST Kieran Bingham wrote:
> On 21/04/18 13:44, Laurent Pinchart wrote:
> > The pixel rate, as reported by the V4L2_CID_PIXEL_RATE control, must
> > include both horizontal and vertical blanking. Both the AFE and HDMI
> > receiver program it incorrectly:
> >
> > - The HDMI receiver goes to the trouble of removing blanking to compute
> > the rate of active pixels. This is easy to fix by removing the
> > computation and returning the incoming pixel clock rate directly.
> >
> > - The AFE performs similar calculation, while it should simply return
> > the fixed pixel rate for analog sources, mandated by the ADV748x to be
> > 28.63636 MHz.
> >
> > Signed-off-by: Laurent Pinchart
> > <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>
>
> This looks quite reasonable, and simplifies the code. Win win.
>
> I presume this will have implications on the pixel receiver side (VIN in our
> case)... are there changes required there, or was it 'just wrong' here.
No change should be required on the VIN side. This patch was prompted by a BSP
patch for VIN that aimed at fixing the same issue, but in the wrong location.
See message 2461975.rTQ0tvdgNJ@avalon in the "[periperi] 2018-04-05 Multimedia
group chat report" thread (Date: Sat, 21 Apr 2018 15:49:49 +0300).
> Either way,
>
> Reviewed-by: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx>
As you maintain the adv748x driver, could you make sure this patch gets
upstream ? :-)
> > ---
> >
> > drivers/media/i2c/adv748x/adv748x-afe.c | 11 +++++------
> > drivers/media/i2c/adv748x/adv748x-hdmi.c | 8 +-------
> > 2 files changed, 6 insertions(+), 13 deletions(-)
> >
> > diff --git a/drivers/media/i2c/adv748x/adv748x-afe.c
> > b/drivers/media/i2c/adv748x/adv748x-afe.c index
> > 61514bae7e5c..3e18d5ae813b 100644
> > --- a/drivers/media/i2c/adv748x/adv748x-afe.c
> > +++ b/drivers/media/i2c/adv748x/adv748x-afe.c
> > @@ -321,17 +321,16 @@ static const struct v4l2_subdev_video_ops
> > adv748x_afe_video_ops = {
> > static int adv748x_afe_propagate_pixelrate(struct adv748x_afe *afe)
> > {
> > struct v4l2_subdev *tx;
> > - unsigned int width, height, fps;
> >
> > tx = adv748x_get_remote_sd(&afe->pads[ADV748X_AFE_SOURCE]);
> > if (!tx)
> > return -ENOLINK;
> >
> > - width = 720;
> > - height = afe->curr_norm & V4L2_STD_525_60 ? 480 : 576;
> > - fps = afe->curr_norm & V4L2_STD_525_60 ? 30 : 25;
> > -
> > - return adv748x_csi2_set_pixelrate(tx, width * height * fps);
> > + /*
> > + * The ADV748x samples analog video signals using an externally
supplied
> > + * clock whose frequency is required to be 28.63636 MHz.
> > + */
> > + return adv748x_csi2_set_pixelrate(tx, 28636360);
> > }
> >
> > static int adv748x_afe_enum_mbus_code(struct v4l2_subdev *sd,
> > diff --git a/drivers/media/i2c/adv748x/adv748x-hdmi.c
> > b/drivers/media/i2c/adv748x/adv748x-hdmi.c index
> > 10d229a4f088..aecc2a84dfec 100644
> > --- a/drivers/media/i2c/adv748x/adv748x-hdmi.c
> > +++ b/drivers/media/i2c/adv748x/adv748x-hdmi.c
> > @@ -402,8 +402,6 @@ static int adv748x_hdmi_propagate_pixelrate(struct
> > adv748x_hdmi *hdmi)>
> > {
> > struct v4l2_subdev *tx;
> > struct v4l2_dv_timings timings;
> > - struct v4l2_bt_timings *bt = &timings.bt;
> > - unsigned int fps;
> >
> > tx = adv748x_get_remote_sd(&hdmi->pads[ADV748X_HDMI_SOURCE]);
> > if (!tx)
> > @@ -411,11 +409,7 @@ static int adv748x_hdmi_propagate_pixelrate(struct
> > adv748x_hdmi *hdmi)
> > adv748x_hdmi_query_dv_timings(&hdmi->sd, &timings);
> >
> > - fps = DIV_ROUND_CLOSEST_ULL(bt->pixelclock,
> > - V4L2_DV_BT_FRAME_WIDTH(bt) *
> > - V4L2_DV_BT_FRAME_HEIGHT(bt));
> > -
> > - return adv748x_csi2_set_pixelrate(tx, bt->width * bt->height * fps);
> > + return adv748x_csi2_set_pixelrate(tx, timings.bt.pixelclock);
> > }
> >
> > static int adv748x_hdmi_enum_mbus_code(struct v4l2_subdev *sd,
--
Regards,
Laurent Pinchart
