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| author | Daniel Scheller <d.scheller@gmx.net> | 2017-04-09 16:38:24 -0300 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@s-opensource.com> | 2017-06-20 09:56:51 -0300 |
| commit | df61f828d4e5f6db7936a21afeef1d5cb6248b4b (patch) | |
| tree | d496305f410104e6d9bfc4de7b39ef96deb34d97 /drivers/media | |
| parent | bf51bbb0448e919181294c268a15a2d119ed9a4e (diff) | |
| download | linux-df61f828d4e5f6db7936a21afeef1d5cb6248b4b.tar.bz2 | |
[media] dvb-frontends/cxd2841er: improved snr reporting
On DVB-T/T2 at least, SNR might be reported as >2500dB, which not only is
just wrong but also ridiculous, so fix this by improving the conversion
of the register value.
The INTLOG10X100 function/macro and the way the values are converted were
both taken from DD's cxd2843 driver.
Signed-off-by: Daniel Scheller <d.scheller@gmx.net>
Acked-by: Abylay Ospan <aospan@netup.ru>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Diffstat (limited to 'drivers/media')
| -rw-r--r-- | drivers/media/dvb-frontends/cxd2841er.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/media/dvb-frontends/cxd2841er.c b/drivers/media/dvb-frontends/cxd2841er.c index d9e8be50c5fa..08f67d60a7d9 100644 --- a/drivers/media/dvb-frontends/cxd2841er.c +++ b/drivers/media/dvb-frontends/cxd2841er.c @@ -38,6 +38,8 @@ #define MAX_WRITE_REGSIZE 16 #define LOG2_E_100X 144 +#define INTLOG10X100(x) ((u32) (((u64) intlog10(x) * 100) >> 24)) + /* DVB-C constellation */ enum sony_dvbc_constellation_t { SONY_DVBC_CONSTELLATION_16QAM, @@ -1817,7 +1819,7 @@ static int cxd2841er_read_snr_t(struct cxd2841er_priv *priv, u32 *snr) } if (reg > 4996) reg = 4996; - *snr = 10000 * ((intlog10(reg) - intlog10(5350 - reg)) >> 24) + 28500; + *snr = 100 * ((INTLOG10X100(reg) - INTLOG10X100(5350 - reg)) + 285); return 0; } @@ -1846,8 +1848,7 @@ static int cxd2841er_read_snr_t2(struct cxd2841er_priv *priv, u32 *snr) } if (reg > 10876) reg = 10876; - *snr = 10000 * ((intlog10(reg) - - intlog10(12600 - reg)) >> 24) + 32000; + *snr = 100 * ((INTLOG10X100(reg) - INTLOG10X100(12600 - reg)) + 320); return 0; } |