Hi Mauro,

thanks for your feedback.

On 18-07-30 15:00, Mauro Carvalho Chehab wrote:
> Em Thu, 28 Jun 2018 18:20:45 +0200
> Marco Felsch <m.fel...@pengutronix.de> escreveu:
> 
> > From: Philipp Zabel <p.za...@pengutronix.de>
> > 
> > To avoid short frames on stream start, keep output pins at high impedance
> > while we are not properly locked onto the input signal.
> > 
> > Signed-off-by: Philipp Zabel <p.za...@pengutronix.de>
> > Signed-off-by: Marco Felsch <m.fel...@pengutronix.de>
> > ---
> >  drivers/media/i2c/tvp5150.c | 39 ++++++++++++++++++++++++++-----------
> >  1 file changed, 28 insertions(+), 11 deletions(-)
> > 
> > diff --git a/drivers/media/i2c/tvp5150.c b/drivers/media/i2c/tvp5150.c
> > index d8bdbedd8826..27cfd08be3d2 100644
> > --- a/drivers/media/i2c/tvp5150.c
> > +++ b/drivers/media/i2c/tvp5150.c
> > @@ -60,6 +60,7 @@ struct tvp5150 {
> >     v4l2_std_id detected_norm;
> >     u32 input;
> >     u32 output;
> > +   u32 oe;
> >     int enable;
> >     bool lock;
> >  
> > @@ -799,14 +800,20 @@ static irqreturn_t tvp5150_isr(int irq, void *dev_id)
> >  {
> >     struct tvp5150 *decoder = dev_id;
> >     struct regmap *map = decoder->regmap;
> > -   unsigned int active = 0, status = 0;
> > +   unsigned int mask, active = 0, status = 0;
> > +
> > +   mask = TVP5150_MISC_CTL_YCBCR_OE | TVP5150_MISC_CTL_SYNC_OE |
> > +          TVP5150_MISC_CTL_CLOCK_OE;
> >  
> >     regmap_read(map, TVP5150_INT_STATUS_REG_A, &status);
> >     if (status) {
> >             regmap_write(map, TVP5150_INT_STATUS_REG_A, status);
> >  
> > -           if (status & TVP5150_INT_A_LOCK)
> > +           if (status & TVP5150_INT_A_LOCK) {
> >                     decoder->lock = !!(status & TVP5150_INT_A_LOCK_STATUS);
> > +                   regmap_update_bits(map, TVP5150_MISC_CTL, mask,
> > +                                      decoder->lock ? decoder->oe : 0);
> > +           }
> >  
> >             return IRQ_HANDLED;
> >     }
> > @@ -872,10 +879,26 @@ static int tvp5150_enable(struct v4l2_subdev *sd)
> >     /* Disable autoswitch mode */
> >     tvp5150_set_std(sd, std);
> >  
> > -   if (decoder->mbus_type == V4L2_MBUS_PARALLEL)
> > +   /*
> > +    * Enable the YCbCr and clock outputs. In discrete sync mode
> > +    * (non-BT.656) additionally enable the the sync outputs.
> > +    */
> > +   switch (decoder->mbus_type) {
> > +   case V4L2_MBUS_PARALLEL:
> >             /* 8-bit 4:2:2 YUV with discrete sync output */
> >             regmap_update_bits(decoder->regmap, TVP5150_DATA_RATE_SEL,
> >                                0x7, 0x0);
> > +           decoder->oe = TVP5150_MISC_CTL_YCBCR_OE |
> > +                         TVP5150_MISC_CTL_CLOCK_OE |
> > +                         TVP5150_MISC_CTL_SYNC_OE;
> > +           break;
> > +   case V4L2_MBUS_BT656:
> > +           decoder->oe = TVP5150_MISC_CTL_YCBCR_OE |
> > +                         TVP5150_MISC_CTL_CLOCK_OE;
> > +           break;
> > +   default:
> > +           return -EINVAL;
> > +   }
> >  
> >     return 0;
> >  };
> > @@ -1190,14 +1213,8 @@ static int tvp5150_s_stream(struct v4l2_subdev *sd, 
> > int enable)
> >     if (enable) {
> >             tvp5150_enable(sd);
> >  
> > -           /*
> > -            * Enable the YCbCr and clock outputs. In discrete sync mode
> > -            * (non-BT.656) additionally enable the the sync outputs.
> > -            */
> > -           val = TVP5150_MISC_CTL_YCBCR_OE | TVP5150_MISC_CTL_CLOCK_OE;
> > -           if (decoder->mbus_type == V4L2_MBUS_PARALLEL)
> > -                   val |= TVP5150_MISC_CTL_SYNC_OE;
> > -
> > +           /* Enable outputs if decoder is locked */
> > +           val = decoder->lock ? decoder->oe : 0;
> 
> Hmm... this only works if the tvp5150 has the interrupts enabled.
> 
> The code should be, instead:
> 
>       if (c->irq)
>               val = decoder->lock ? decoder->oe : 0;
>       else
>               val = decoder->oe;

The previous patch "[media] tvp5150: Add sync lock interrupt handling"
adds the look mechanism. As you can see the lock will be always true
if there is no interrupt support during probe():

core->irq = c->irq;
tvp5150_reset(sd, 0);   /* Calls v4l2_ctrl_handler_setup() */
if (c->irq) {
        res = devm_request_threaded_irq(&c->dev, c->irq,
                        NULL,
                        tvp5150_isr,
                        IRQF_TRIGGER_HIGH |
                        IRQF_ONESHOT,
                        "tvp5150", core);
        if (res)
                return res;
} else {
        core->lock = true;
}

I'am with you that your s_stream version looks a bit nicer but adds the
check again.

Regards,
Marco

> 
> >             int_val = TVP5150_INT_A_LOCK;
> >     }
> >  
> 
> 
> 
> Thanks,
> Mauro
> 

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