media: tuner-simple: fix regression in simple_set_radio_freq

[ Upstream commit 505bfc2a142f12ce7bc7a878b44abc3496f2e747 ]

clang static analysis reports this problem

tuner-simple.c:714:13: warning: Assigned value is
  garbage or undefined
        buffer[1] = buffer[3];
                  ^ ~~~~~~~~~
In simple_set_radio_freq buffer[3] used to be done
in-function with a switch of tuner type, now done
by a call to simple_radio_bandswitch which has this case

	case TUNER_TENA_9533_DI:
	case TUNER_YMEC_TVF_5533MF:
		tuner_dbg("This tuner doesn't ...
		return 0;

which does not set buffer[3].  In the old logic, this case
would have returned 0 from simple_set_radio_freq.

Recover this old behavior by returning an error for this
codition. Since the old simple_set_radio_freq behavior
returned a 0, do the same.

Fixes: c7a9f3aa1e1b ("V4L/DVB (7129): tuner-simple: move device-specific code into three separate functions")
Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/media/tuners/tuner-simple.c b/drivers/media/tuners/tuner-simple.c
index cf44d3657f5550299987fb122d754c8cf081769e..9b2501046bd147ae0ebef469deca75a15b99451d 100644 (file)
--- a/drivers/media/tuners/tuner-simple.c
+++ b/drivers/media/tuners/tuner-simple.c
@@ -499,7 +499,7 @@ static int simple_radio_bandswitch(struct dvb_frontend *fe, u8 *buffer)
        case TUNER_TENA_9533_DI:
        case TUNER_YMEC_TVF_5533MF:
                tuner_dbg("This tuner doesn't have FM. Most cards have a TEA5767 for FM\n");
-               return 0;
+               return -EINVAL;
        case TUNER_PHILIPS_FM1216ME_MK3:
        case TUNER_PHILIPS_FM1236_MK3:
        case TUNER_PHILIPS_FMD1216ME_MK3:
@@ -700,7 +700,8 @@ static int simple_set_radio_freq(struct dvb_frontend *fe,
                    TUNER_RATIO_SELECT_50; /* 50 kHz step */
 
        /* Bandswitch byte */
-       simple_radio_bandswitch(fe, &buffer[0]);
+       if (simple_radio_bandswitch(fe, &buffer[0]))
+               return 0;
 
        /* Convert from 1/16 kHz V4L steps to 1/20 MHz (=50 kHz) PLL steps
           freq * (1 Mhz / 16000 V4L steps) * (20 PLL steps / 1 MHz) =