Re: [PATCH 2/2] af9033: fix DVBv3 snr value not correct issue

[Antti Palosaari <crope@iki.fi>]

Moikka
That changes DVBv3 SNR reporting from 0.1dB units to relative between 
0-0xffff. For AF9033 it has been 0.1dB ages and I would like to keep it 
as it is. So add logic here to return 0.1dB as it did for AF9033 and do 
what you like for IT9133.

On switch-case default branch af9033_stat_work() jumps out. That will 
stop statistics polling. It is not hard error case you want to stop 
polling, so you need to jump case where it schedules new work. Hard 
errors where you like to stop polling are those I/O errors (reg read, 
reg write).

Otherwise it looks OK.

regards
Antti


On 10/02/2014 08:34 AM, Bimow Chen wrote:
> Snr returns value not correct. Fix it.
>
>
> 0002-af9033-fix-DVBv3-snr-value-not-correct-issue.patch
>
>
>>From 7b7d83e669e1c7a041241c7412fd05a5ca73815c Mon Sep 17 00:00:00 2001
> From: Bimow Chen<Bimow.Chen@ite.com.tw>
> Date: Thu, 2 Oct 2014 10:37:13 +0800
> Subject: [PATCH 2/2] af9033: fix DVBv3 snr value not correct issue
>
> Snr returns value not correct. Fix it.
>
> Signed-off-by: Bimow Chen<Bimow.Chen@ite.com.tw>
> ---
>   drivers/media/dvb-frontends/af9033.c      |   61 +++++++++++++++++++++++++++-
>   drivers/media/dvb-frontends/af9033_priv.h |    5 ++-
>   2 files changed, 62 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/media/dvb-frontends/af9033.c b/drivers/media/dvb-frontends/af9033.c
> index 2b3d2f0..ad4ff78 100644
> --- a/drivers/media/dvb-frontends/af9033.c
> +++ b/drivers/media/dvb-frontends/af9033.c
> @@ -849,14 +849,42 @@ static int af9033_read_snr(struct dvb_frontend *fe, u16 *snr)
>   {
>   	struct af9033_dev *dev = fe->demodulator_priv;
>   	struct dtv_frontend_properties *c = &dev->fe.dtv_property_cache;
> +	int ret;
> +	u8 u8tmp;
>
>   	/* use DVBv5 CNR */
> -	if (c->cnr.stat[0].scale == FE_SCALE_DECIBEL)
> -		*snr = div_s64(c->cnr.stat[0].svalue, 100); /* 1000x => 10x */
> -	else
> +	if (c->cnr.stat[0].scale == FE_SCALE_DECIBEL) {
> +		*snr = div_s64(c->cnr.stat[0].svalue, 1000);
> +
> +		/* read current modulation */
> +		ret = af9033_rd_reg(dev, 0x80f903, &u8tmp);
> +		if (ret)
> +			goto err;
> +
> +		/* scale value to 0x0000-0xffff */
> +		switch ((u8tmp >> 0) & 3) {
> +		case 0:
> +			*snr = *snr * 0xFFFF / 23;
> +			break;
> +		case 1:
> +			*snr = *snr * 0xFFFF / 26;
> +			break;
> +		case 2:
> +			*snr = *snr * 0xFFFF / 32;
> +			break;
> +		default:
> +			goto err;
> +		}
> +	} else {
>   		*snr = 0;
> +	}
>
>   	return 0;
> +
> +err:
> +	dev_dbg(&dev->client->dev, "failed=%d\n", ret);
> +
> +	return ret;
>   }
>
>   static int af9033_read_signal_strength(struct dvb_frontend *fe, u16 *strength)
> @@ -1038,6 +1066,33 @@ static void af9033_stat_work(struct work_struct *work)
>
>   		snr_val = (buf[2] << 16) | (buf[1] << 8) | (buf[0] << 0);
>
> +		/* read superframe number */
> +		ret = af9033_rd_reg(dev, 0x80f78b, &u8tmp);
> +		if (ret)
> +			goto err;
> +
> +		if (u8tmp)
> +			snr_val /= u8tmp;
> +
> +		/* read current transmission mode */
> +		ret = af9033_rd_reg(dev, 0x80f900, &u8tmp);
> +		if (ret)
> +			goto err;
> +
> +		switch ((u8tmp >> 0) & 3) {
> +		case 0:
> +			snr_val *= 4;
> +			break;
> +		case 1:
> +			snr_val *= 1;
> +			break;
> +		case 2:
> +			snr_val *= 2;
> +			break;
> +		default:
> +			goto err;
> +		}
> +
>   		/* read current modulation */
>   		ret = af9033_rd_reg(dev, 0x80f903, &u8tmp);
>   		if (ret)
> diff --git a/drivers/media/dvb-frontends/af9033_priv.h b/drivers/media/dvb-frontends/af9033_priv.h
> index c9c8798..8e23275 100644
> --- a/drivers/media/dvb-frontends/af9033_priv.h
> +++ b/drivers/media/dvb-frontends/af9033_priv.h
> @@ -181,7 +181,10 @@ static const struct val_snr qam64_snr_lut[] = {
>   	{ 0x05570d, 26 },
>   	{ 0x059feb, 27 },
>   	{ 0x05bf38, 28 },
> -	{ 0xffffff, 29 },
> +	{ 0x05f78f, 29 },
> +	{ 0x0612c3, 30 },
> +	{ 0x0626be, 31 },
> +	{ 0xffffff, 32 },
>   };
>
>   static const struct reg_val ofsm_init[] = {
> -- 1.7.0.4
>

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