diff options
| author | Mauro Carvalho Chehab <mchehab@osg.samsung.com> | 2015-11-09 23:24:10 -0200 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@osg.samsung.com> | 2015-11-17 06:37:16 -0200 |
| commit | 4deea4cb471354a8abdeecc9a571dfdbac8c2481 (patch) | |
| tree | bad0292cbd21601a239b527577e27e3ffd4a425c /drivers/media/dvb-core/dvb_frontend.c | |
| parent | 6747b39441925f247f15d04b89be3588f465ad57 (diff) | |
[media] dvb: document dvb_frontend_sleep_until()
This function is used mainly at the DVB core, in order to provide
emulation for a legacy ioctl. The only current exception is
the stv0299 driver, with takes more than 8ms to switch voltage,
breaking the emulation for FE_DISHNETWORK_SEND_LEGACY_CMD.
Document that.
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Diffstat (limited to 'drivers/media/dvb-core/dvb_frontend.c')
| -rw-r--r-- | drivers/media/dvb-core/dvb_frontend.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/drivers/media/dvb-core/dvb_frontend.c b/drivers/media/dvb-core/dvb_frontend.c index c38ef1a72b4a..d764cffb2102 100644 --- a/drivers/media/dvb-core/dvb_frontend.c +++ b/drivers/media/dvb-core/dvb_frontend.c @@ -891,10 +891,11 @@ static void dvb_frontend_stop(struct dvb_frontend *fe) } /* - * Sleep until gettimeofday() > waketime + add_usec - * This needs to be as precise as possible, but as the delay is - * usually between 2ms and 32ms, it is done using a scheduled msleep - * followed by usleep (normally a busy-wait loop) for the remainder + * Sleep for the amount of time given by add_usec parameter + * + * This needs to be as precise as possible, as it affects the detection of + * the dish tone command at the satellite subsystem. The precision is improved + * by using a scheduled msleep followed by udelay for the remainder. */ void dvb_frontend_sleep_until(ktime_t *waketime, u32 add_usec) { |