From 0de04ca1dc0bd38fd7b88871ab9a17e2d8dbd0db Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Fri, 4 Jul 2014 14:15:36 -0300 Subject: [PATCH] [media] dib0090: Fix the sleep time at the state machine msleep() is not too precise: its precision depends on the HZ config. As the driver selects precise timings for the state machine, change it to usleep_range(). Acked-By: Patrick Boettcher Signed-off-by: Mauro Carvalho Chehab --- drivers/media/dvb-frontends/dib0090.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/drivers/media/dvb-frontends/dib0090.c b/drivers/media/dvb-frontends/dib0090.c index 3ee22ff76315..68e2af2650d3 100644 --- a/drivers/media/dvb-frontends/dib0090.c +++ b/drivers/media/dvb-frontends/dib0090.c @@ -2557,10 +2557,19 @@ static int dib0090_set_params(struct dvb_frontend *fe) do { ret = dib0090_tune(fe); - if (ret != FE_CALLBACK_TIME_NEVER) - msleep(ret / 10); - else + if (ret == FE_CALLBACK_TIME_NEVER) break; + + /* + * Despite dib0090_tune returns time at a 0.1 ms range, + * the actual sleep time depends on CONFIG_HZ. The worse case + * is when CONFIG_HZ=100. In such case, the minimum granularity + * is 10ms. On some real field tests, the tuner sometimes don't + * lock when this timer is lower than 10ms. So, enforce a 10ms + * granularity and use usleep_range() instead of msleep(). + */ + ret = 10 * (ret + 99)/100; + usleep_range(ret * 1000, (ret + 1) * 1000); } while (state->tune_state != CT_TUNER_STOP); return 0; -- 2.11.0