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().
Signed-off-by: Mauro Carvalho Chehab <m.chehab@xxxxxxxxxxx>
---
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;
--
1.9.3
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