From 4c12adad26f059fa207d6b07aa61f39bc459211b Mon Sep 17 00:00:00 2001 From: David Howells Date: Thu, 9 Apr 2015 16:36:49 -0300 Subject: [PATCH] [media] dvb: Document FE_SCALE_DECIBEL units consistently In comments and in the documentation, the units of properties marked with the FE_SCALE_DECIBEL scale are specified in terms of 1/1000 dB or 0.0001 dB. This is inconsistent, however, as 1/1000 is 0.001, not 0.0001. Note that the v4l-utils divide the value by 1000 for the signal strength suggesting that the 1/1000 is correct. Settle on millidecibels, ie. 1/1000dB or 0.001dB. Signed-off-by: David Howells Signed-off-by: Mauro Carvalho Chehab --- Documentation/DocBook/media/dvb/dvbproperty.xml | 4 ++-- include/uapi/linux/dvb/frontend.h | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/Documentation/DocBook/media/dvb/dvbproperty.xml b/Documentation/DocBook/media/dvb/dvbproperty.xml index 3018564ddfd9..7ddab2ba9b40 100644 --- a/Documentation/DocBook/media/dvb/dvbproperty.xml +++ b/Documentation/DocBook/media/dvb/dvbproperty.xml @@ -953,7 +953,7 @@ enum fe_interleaving { Possible scales for this metric are: FE_SCALE_NOT_AVAILABLE - it failed to measure it, or the measurement was not complete yet. - FE_SCALE_DECIBEL - signal strength is in 0.0001 dBm units, power measured in miliwatts. This value is generally negative. + FE_SCALE_DECIBEL - signal strength is in 0.001 dBm units, power measured in miliwatts. This value is generally negative. FE_SCALE_RELATIVE - The frontend provides a 0% to 100% measurement for power (actually, 0 to 65535). @@ -963,7 +963,7 @@ enum fe_interleaving { Possible scales for this metric are: FE_SCALE_NOT_AVAILABLE - it failed to measure it, or the measurement was not complete yet. - FE_SCALE_DECIBEL - Signal/Noise ratio is in 0.0001 dB units. + FE_SCALE_DECIBEL - Signal/Noise ratio is in 0.001 dB units. FE_SCALE_RELATIVE - The frontend provides a 0% to 100% measurement for Signal/Noise (actually, 0 to 65535). diff --git a/include/uapi/linux/dvb/frontend.h b/include/uapi/linux/dvb/frontend.h index c56d77c496a5..466f56997272 100644 --- a/include/uapi/linux/dvb/frontend.h +++ b/include/uapi/linux/dvb/frontend.h @@ -467,7 +467,7 @@ struct dtv_cmds_h { * @FE_SCALE_NOT_AVAILABLE: That QoS measure is not available. That * could indicate a temporary or a permanent * condition. - * @FE_SCALE_DECIBEL: The scale is measured in 0.0001 dB steps, typically + * @FE_SCALE_DECIBEL: The scale is measured in 0.001 dB steps, typically * used on signal measures. * @FE_SCALE_RELATIVE: The scale is a relative percentual measure, * ranging from 0 (0%) to 0xffff (100%). @@ -516,7 +516,7 @@ struct dtv_stats { __u8 scale; /* enum fecap_scale_params type */ union { __u64 uvalue; /* for counters and relative scales */ - __s64 svalue; /* for 0.0001 dB measures */ + __s64 svalue; /* for 0.001 dB measures */ }; } __attribute__ ((packed));