media: rtl28xxu: add missing sleep before probing slave demod

Slave demod needs some time to wake up otherwise it may not respond to the
following probe commands. This problem manifested randomly on my Astrometa
DVB-T2 dongle.

Signed-off-by: Mario Hros <git@reversity.org>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

diff --git a/drivers/media/usb/dvb-usb-v2/rtl28xxu.c b/drivers/media/usb/dvb-usb-v2/rtl28xxu.c
index c6881a1b32324910aa91364aad857c963b84719f..2080f6ef4be1229f1a38152b12625b0335ee7625 100644 (file)
--- a/drivers/media/usb/dvb-usb-v2/rtl28xxu.c
+++ b/drivers/media/usb/dvb-usb-v2/rtl28xxu.c
@@ -552,6 +552,9 @@ tuner_found:
                if (ret)
                        goto err;
 
+               /* slave demod needs some time to wake up */
+               msleep(20);
+
                /* check slave answers */
                ret = rtl28xxu_ctrl_msg(d, &req_mn88472);
                if (ret == 0 && buf[0] == 0x02) {