V4L/DVB (12269): af9013: auto-detect parameters in case of garbage given by app

Request demodulator auto-detect transmission parameters in case of
garbage parameters provided by application for compatibility.
That's needed at least for MPlayer compatibility currently.

Thanks to Jelle de Jong for reporting issue and providing SSH access to
Devin for debugging.

Thanks to Devin Heitmueller for hard debug work he did to find that bug.

Cc: Devin Heitmueller <dheitmueller@kernellabs.com>
Cc: Jelle de Jong <jelledejong@powercraft.nl>
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/dvb/frontends/af9013.c

@@ -527,6 +527,10 @@ static int af9013_set_ofdm_params(struct af9013_state *state,
 	u8 i, buf[3] = {0, 0, 0};
 	*auto_mode = 0; /* set if parameters are requested to auto set */
 
+	/* Try auto-detect transmission parameters in case of AUTO requested or
+	   garbage parameters given by application for compatibility.
+	   MPlayer seems to provide garbage parameters currently. */
+
 	switch (params->transmission_mode) {
 	case TRANSMISSION_MODE_AUTO:
 		*auto_mode = 1;
@@ -536,7 +540,8 @@ static int af9013_set_ofdm_params(struct af9013_state *state,
 		buf[0] |= (1 << 0);
 		break;
 	default:
-		return -EINVAL;
+		deb_info("%s: invalid transmission_mode\n", __func__);
+		*auto_mode = 1;
 	}
 
 	switch (params->guard_interval) {
@@ -554,7 +559,8 @@ static int af9013_set_ofdm_params(struct af9013_state *state,
 		buf[0] |= (3 << 2);
 		break;
 	default:
-		return -EINVAL;
+		deb_info("%s: invalid guard_interval\n", __func__);
+		*auto_mode = 1;
 	}
 
 	switch (params->hierarchy_information) {
@@ -572,7 +578,8 @@ static int af9013_set_ofdm_params(struct af9013_state *state,
 		buf[0] |= (3 << 4);
 		break;
 	default:
-		return -EINVAL;
+		deb_info("%s: invalid hierarchy_information\n", __func__);
+		*auto_mode = 1;
 	};
 
 	switch (params->constellation) {
@@ -587,7 +594,8 @@ static int af9013_set_ofdm_params(struct af9013_state *state,
 		buf[1] |= (2 << 6);
 		break;
 	default:
-		return -EINVAL;
+		deb_info("%s: invalid constellation\n", __func__);
+		*auto_mode = 1;
 	}
 
 	/* Use HP. How and which case we can switch to LP? */
@@ -611,7 +619,8 @@ static int af9013_set_ofdm_params(struct af9013_state *state,
 		buf[2] |= (4 << 0);
 		break;
 	default:
-		return -EINVAL;
+		deb_info("%s: invalid code_rate_HP\n", __func__);
+		*auto_mode = 1;
 	}
 
 	switch (params->code_rate_LP) {
@@ -638,7 +647,8 @@ static int af9013_set_ofdm_params(struct af9013_state *state,
 		if (params->hierarchy_information == HIERARCHY_AUTO)
 			break;
 	default:
-		return -EINVAL;
+		deb_info("%s: invalid code_rate_LP\n", __func__);
+		*auto_mode = 1;
 	}
 
 	switch (params->bandwidth) {
@@ -651,7 +661,8 @@ static int af9013_set_ofdm_params(struct af9013_state *state,
 		buf[1] |= (2 << 2);
 		break;
 	default:
-		return -EINVAL;
+		deb_info("%s: invalid bandwidth\n", __func__);
+		buf[1] |= (2 << 2); /* cannot auto-detect BW, try 8 MHz */
 	}
 
 	/* program */