Re: [PATCH 16/22] [media] tvp5150: add querystd

[Marco Felsch <m.felsch@pengutronix.de>]

Hi Ian,

On 18-08-02 11:54, Ian Arkver wrote:
> On 02/08/18 10:49, Mauro Carvalho Chehab wrote:
> > Em Thu, 2 Aug 2018 10:01:01 +0200
> > Marco Felsch <m.felsch@pengutronix.de> escreveu:
> > 
> > > Hi Mauro,
> > > 
> > > On 18-08-01 12:50, Mauro Carvalho Chehab wrote:
> > > > Em Wed, 1 Aug 2018 16:49:26 +0200
> > > > Marco Felsch <m.felsch@pengutronix.de> escreveu:
> > > > > Hi Mauro,
> > > > > 
> > > > > On 18-08-01 11:22, Mauro Carvalho Chehab wrote:
> > > > > > Em Wed, 1 Aug 2018 15:21:25 +0200
> > > > > > Marco Felsch <m.felsch@pengutronix.de> escreveu:
> > > > > > > Hi Mauro,
> > > > > > > 
> > > > > > > On 18-07-30 15:09, Mauro Carvalho Chehab wrote:
> > > > > > > > Em Thu, 28 Jun 2018 18:20:48 +0200
> > > > > > > > Marco Felsch <m.felsch@pengutronix.de> escreveu:
> > > > > > > > > From: Philipp Zabel <p.zabel@pengutronix.de>
> > > > > > > > > 
> > > > > > > > > Add the querystd video_op and make it return V4L2_STD_UNKNOWN while the
> > > > > > > > > TVP5150 is not locked to a signal.
> > > > > > > > > 
> > > > > > > > > Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
> > > > > > > > > Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
> > > > > > > > > ---
> > > > > > > > >   drivers/media/i2c/tvp5150.c | 10 ++++++++++
> > > > > > > > >   1 file changed, 10 insertions(+)
> > > > > > > > > 
> > > > > > > > > diff --git a/drivers/media/i2c/tvp5150.c b/drivers/media/i2c/tvp5150.c
> > > > > > > > > index 99d887936ea0..1990aaa17749 100644
> > > > > > > > > --- a/drivers/media/i2c/tvp5150.c
> > > > > > > > > +++ b/drivers/media/i2c/tvp5150.c
> > > > > > > > > @@ -796,6 +796,15 @@ static v4l2_std_id tvp5150_read_std(struct v4l2_subdev *sd)
> > > > > > > > >   	}
> > > > > > > > >   }
> > > > > > > > > +static int tvp5150_querystd(struct v4l2_subdev *sd, v4l2_std_id *std_id)
> > > > > > > > > +{
> > > > > > > > > +	struct tvp5150 *decoder = to_tvp5150(sd);
> > > > > > > > > +
> > > > > > > > > +	*std_id = decoder->lock ? tvp5150_read_std(sd) : V4L2_STD_UNKNOWN;
> > > > > > > > 
> > > > > > > > This patch requires rework. What happens when a device doesn't have
> > > > > > > > IRQ enabled? Perhaps it should, instead, read some register in order
> > > > > > > > to check for the locking status, as this would work on both cases.
> > > > > > > 
> > > > > > > If IRQ isn't enabled, decoder->lock is set to always true during
> > > > > > > probe(). So this case should be fine.
> > > > > > 
> > > > > > Not sure if tvp5150_read_std() will do the right thing. If it does,
> > > > > > the above could simply be:
> > > > > > 	std_id = tvp5150_read_std(sd);
> > > > > > 
> > > > > > But, as there are 3 variants of this chipset, it sounds safer to check
> > > > > > if the device is locked before calling tvp5150_read_std().
> > > > > 
> > > > > Yes, I'm with you.
> > > > > > 
> > > > > > IMHO, the best would be to have a patch like the one below.
> > > > > > 
> > > > > > Regards,
> > > > > > Mauro
> > > > > > 
> > > > > > [PATCH] media: tvp5150: implement decoder lock when irq is not used
> > > > > > 
> > > > > > When irq is used, the lock is set via IRQ code. When it isn't,
> > > > > > the driver just assumes it is always locked. Instead, read the
> > > > > > lock status from the status register.
> > > > > 
> > > > > Yes, that is a better solution.
> > > > > > 
> > > > > > Compile-tested only.
> > > > > > 
> > > > > > Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
> > > > > > 
> > > > > > diff --git a/drivers/media/i2c/tvp5150.c b/drivers/media/i2c/tvp5150.c
> > > > > > index 75e5ffc6573d..e07020d4053d 100644
> > > > > > --- a/drivers/media/i2c/tvp5150.c
> > > > > > +++ b/drivers/media/i2c/tvp5150.c
> > > > > > @@ -811,11 +811,24 @@ static v4l2_std_id tvp5150_read_std(struct v4l2_subdev *sd)
> > > > > >   	}
> > > > > >   }
> > > > > > +static int query_lock(struct v4l2_subdev *sd)
> > > > > > +{
> > > > > > +	struct tvp5150 *decoder = to_tvp5150(sd);
> > > > > > +	int status;
> > > > > > +
> > > > > > +	if (decoder->irq)
> > > > > > +		return decoder->lock;
> > > > > > +
> > > > > > +	regmap_read(map, TVP5150_INT_STATUS_REG_A, &status);
> > > > > > +
> > > > > > +	return (status & 0x06) == 0x06;
> > > > > 
> > > > > Typo? It should be 0x80, as described in the datasheet (SLES209E) or
> > > > > just use the TVP5150_INT_A_LOCK_STATUS define. This avoid datasheet
> > > > > cross check during reading.
> > > > 
> > > > Yes, it is a typo, but at the other line... I meant to use the register
> > > > 0x88, e. g.:
> > > > 
> > > > 	regmap_read(decoder->regmap, TVP5150_STATUS_REG_1, &status);
> > > 
> > > During my development I tried this status register too, as descibed on
> > > the community website [1]. But that wasn't that good, because the look
> > > will be lost very often. Bit7 of Interrupt Status Reg A (0xc0) is more
> > > robust for that kind of work, since it covers the whole signal.
> > > 
> > > [1] http://e2e.ti.com/support/data_converters/videoconverters/f/918/p/ \
> > > 	617120/2273276?keyMatch=tvp5150%20lock%20lost&tisearch=Search-EN-Support
> > 
> > Bit 4 is not reliable for such purpose, but, on my tests, when video is
> > present, bits 1, 2 and 3 are present when there is a proper signal.
> > Basically, all the times I issued a std query ioctl, it reads 0x1e.
> > 
> > When the signal is removed, I get a 0x00.
> > 
> > Here, reading int status reg A returns 0x40 with or without signal,
> > probably because IRQ is not enabled. See, for USB devices like em28xx,
> > we don't have direct access to tvp5051 IRQ line. If the IRQ lines is
> > somewhat wired to em28xx, it could be possible that the em28xx would
> > handle it, but we would need to know a way to setup em28xx to handle irqs.
> > I don't know if this is possible, and, if so, how em28xx would be
> > notifying such interrupts via some URB packet.
> 
> The interrupt status register bits are latched and need a 1 written to clear
> them. Normally this would be done by the interrupt handler. Maybe this is
> why you're seeing the LOCK bit stuck?

Yes, you're right. I forgot that behaviour but anyway, 0x40 just
indicates there was a lock change. Using that bit for a lock check
requires the status register #1 to check the dedicated locks.

Regards,
Marco

> 
> Regards,
> Ian
> 
> > 
> > > > 
> > > > I ran some tests here: the int status reg is not updated.
> > > > 
> > > > Also, after thinking a little bit, I opted to not use the query_lock()
> > > > at s_stream. It makes no sense there without adding a status polling
> > > > logic. I also opted to remove initializing decoder->lock to true, as
> > > > this is very counter-intuitive. Instead, I'm adding a test at s_stream
> > > > if decoder->irq is set. This makes easier to understand the code.
> > > 
> > > Yes, you're right.
> > > 
> > > > Btw, on my tests here, I noticed a problem with S-Video... at least with
> > > > AV-350 grabber, composite is only working when S-Video is connected.
> > > 
> > > Unfortunately I have only a custom board with one composite connection.
> > > 
> > > > 
> > > > This bug also happens before your patchset, so this is not a regression
> > > > caused by your patches.
> > > > 
> > > > Anyway, patch enclosed. I added it together with my patch series at:
> > > > 
> > > > 	https://git.linuxtv.org/mchehab/experimental.git/log/?h=tvp5150-2
> > > 
> > > Did you drop the DT of_graph support patch? It was there on your first
> > > tvp5150 branch.
> > 
> > Yes. As discussed, I'm waiting for a replacement patch from you. So,
> > after testing, I removed it, in order to make simpler to add your
> > replacement patch.
> > 
> > IMO, the proper mapping is one input linked to (up to) 3 connectors.
> > 
> > Please notice that I'm also waiting for a replacement for patch 06/22
> > (and a rebase for the not-yet-applied patches).
> > 
> > Feel free to send those patches against
> > 	https://git.linuxtv.org/mchehab/experimental.git/log/?h=tvp5150-3
> > 
> > (no changes on tvp5051 patches here - it is just rebased on the top of
> >   pad-fix-3 branch)
> > 
> > > 
> > > > 
> > > > I'll keep doing more tests here.
> > > > > > +}
> > > > > > +
> > > > > >   static int tvp5150_querystd(struct v4l2_subdev *sd, v4l2_std_id *std_id)
> > > > > >   {
> > > > > >   	struct tvp5150 *decoder = to_tvp5150(sd);
> > > > > > -	*std_id = decoder->lock ? tvp5150_read_std(sd) : V4L2_STD_UNKNOWN;
> > > > > > +	*std_id = query_lock(sd) ? tvp5150_read_std(sd) : V4L2_STD_UNKNOWN;
> > > > > >   	return 0;
> > > > > >   }
> > > > > > @@ -1247,7 +1260,7 @@ static int tvp5150_s_stream(struct v4l2_subdev *sd, int enable)
> > > > > >   		tvp5150_enable(sd);
> > > > > >   		/* Enable outputs if decoder is locked */
> > > > > > -		val = decoder->lock ? decoder->oe : 0;
> > > > > > +		val = query_lock(sd) ? decoder->oe : 0;
> > > > > >   		int_val = TVP5150_INT_A_LOCK;
> > > > > >   		v4l2_subdev_notify_event(&decoder->sd, &tvp5150_ev_fmt);
> > > > > >   	}
> > > > > > @@ -1816,8 +1829,6 @@ static int tvp5150_probe(struct i2c_client *c,
> > > > > >   						IRQF_ONESHOT, "tvp5150", core);
> > > > > >   		if (res)
> > > > > >   			return res;
> > > > > > -	} else {
> > > > > > -		core->lock = true;
> > > > > >   	}
> > > > > >   	res = v4l2_async_register_subdev(sd);
> > > > > > 
> > > > > > 
> > > > 
> > > > [PATCH] media: tvp5150: implement decoder lock when irq is not used
> > > > 
> > > > When irq is used, the lock is set via IRQ code. When it isn't,
> > > > the driver just assumes it is always locked. Instead, read the
> > > > lock status from the status register.
> > > > 
> > > > Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
> > > > 
> > > > diff --git a/drivers/media/i2c/tvp5150.c b/drivers/media/i2c/tvp5150.c
> > > > index efc441df7cac..e74af68be2eb 100644
> > > > --- a/drivers/media/i2c/tvp5150.c
> > > > +++ b/drivers/media/i2c/tvp5150.c
> > > > @@ -810,11 +810,25 @@ static v4l2_std_id tvp5150_read_std(struct v4l2_subdev *sd)
> > > >   	}
> > > >   }
> > > > +static int query_lock(struct v4l2_subdev *sd)
> > > > +{
> > > > +	struct tvp5150 *decoder = to_tvp5150(sd);
> > > > +	int status;
> > > > +
> > > > +	if (decoder->irq)
> > > > +		return decoder->lock;
> > > > +
> > > > +	regmap_read(decoder->regmap, TVP5150_STATUS_REG_1, &status);
> > > > +
> > > > +	/* For standard detection, we need the 3 locks */
> > > > +	return (status & 0x0e) == 0x0e;
> > > > +}
> > > > +
> > > >   static int tvp5150_querystd(struct v4l2_subdev *sd, v4l2_std_id *std_id)
> > > >   {
> > > >   	struct tvp5150 *decoder = to_tvp5150(sd);
> > > 
> > > We should drop the decoder var here and not in the cleanup patch "media:
> > > tvp5150: get rid of some warnings".
> > 
> > I don't like the idea of merging stuff with different things together.
> > One patch per logical change.
> > 
> > > There are always two version of the
> > > patch that remove the 'static' warning [2,3].
> > > 
> > > [2] https://www.spinics.net/lists/linux-media/msg138318.html
> > > [3] https://www.spinics.net/lists/linux-media/msg138363.html
> > 
> > I'll likely just fold the static change with the patch that added
> > the warning when applying mainstream, adding a notice there at the
> > patch's description.
> > 
> > > 
> > > Regards,
> > > Marco
> > > > -	*std_id = decoder->lock ? tvp5150_read_std(sd) : V4L2_STD_UNKNOWN;
> > > > +	*std_id = query_lock(sd) ? tvp5150_read_std(sd) : V4L2_STD_UNKNOWN;
> > > >   	return 0;
> > > >   }
> > > > @@ -1208,7 +1222,10 @@ static int tvp5150_s_stream(struct v4l2_subdev *sd, int enable)
> > > >   		tvp5150_enable(sd);
> > > >   		/* Enable outputs if decoder is locked */
> > > > -		val = decoder->lock ? decoder->oe : 0;
> > > > +		if (decoder->irq)
> > > > +			val = decoder->lock ? decoder->oe : 0;
> > > > +		else
> > > > +			val = decoder->oe;
> > > >   		int_val = TVP5150_INT_A_LOCK;
> > > >   		v4l2_subdev_notify_event(&decoder->sd, &tvp5150_ev_fmt);
> > > >   	}
> > > > @@ -1777,8 +1794,6 @@ static int tvp5150_probe(struct i2c_client *c,
> > > >   						IRQF_ONESHOT, "tvp5150", core);
> > > >   		if (res)
> > > >   			return res;
> > > > -	} else {
> > > > -		core->lock = true;
> > > >   	}
> > > >   	res = v4l2_async_register_subdev(sd);
> > > > 
> > > > 
> > > > 
> > > > Thanks,
> > > > Mauro
> > > 
> > 
> > 
> > 
> > Thanks,
> > Mauro
> > 
> 

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