[media] dtt200u-fe: handle errors on USB control messages

If something goes wrong, return an error code, instead of
assuming that everything went fine.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

diff --git a/drivers/media/usb/dvb-usb/dtt200u-fe.c b/drivers/media/usb/dvb-usb/dtt200u-fe.c
index 7f7f64be63539bea5be83f425cddd610e5e101f9..f5c042baa254e0cf3be54eb759918161f82202b1 100644 (file)
--- a/drivers/media/usb/dvb-usb/dtt200u-fe.c
+++ b/drivers/media/usb/dvb-usb/dtt200u-fe.c
@@ -27,11 +27,17 @@ static int dtt200u_fe_read_status(struct dvb_frontend *fe,
                                  enum fe_status *stat)
 {
        struct dtt200u_fe_state *state = fe->demodulator_priv;
+       int ret;
 
        mutex_lock(&state->data_mutex);
        state->data[0] = GET_TUNE_STATUS;
 
-       dvb_usb_generic_rw(state->d, state->data, 1, state->data, 3, 0);
+       ret = dvb_usb_generic_rw(state->d, state->data, 1, state->data, 3, 0);
+       if (ret < 0) {
+               *stat = 0;
+               mutex_unlock(&state->data_mutex);
+               return ret;
+       }
 
        switch (state->data[0]) {
                case 0x01:
@@ -53,25 +59,30 @@ static int dtt200u_fe_read_status(struct dvb_frontend *fe,
 static int dtt200u_fe_read_ber(struct dvb_frontend* fe, u32 *ber)
 {
        struct dtt200u_fe_state *state = fe->demodulator_priv;
+       int ret;
 
        mutex_lock(&state->data_mutex);
        state->data[0] = GET_VIT_ERR_CNT;
 
-       dvb_usb_generic_rw(state->d, state->data, 1, state->data, 3, 0);
-       *ber = (state->data[0] << 16) | (state->data[1] << 8) | state->data[2];
+       ret = dvb_usb_generic_rw(state->d, state->data, 1, state->data, 3, 0);
+       if (ret >= 0)
+               *ber = (state->data[0] << 16) | (state->data[1] << 8) | state->data[2];
 
        mutex_unlock(&state->data_mutex);
-       return 0;
+       return ret;
 }
 
 static int dtt200u_fe_read_unc_blocks(struct dvb_frontend* fe, u32 *unc)
 {
        struct dtt200u_fe_state *state = fe->demodulator_priv;
+       int ret;
 
        mutex_lock(&state->data_mutex);
        state->data[0] = GET_RS_UNCOR_BLK_CNT;
 
-       dvb_usb_generic_rw(state->d, state->data, 1, state->data, 2, 0);
+       ret = dvb_usb_generic_rw(state->d, state->data, 1, state->data, 2, 0);
+       if (ret >= 0)
+               *unc = (state->data[0] << 8) | state->data[1];
 
        mutex_unlock(&state->data_mutex);
        return ret;
@@ -80,11 +91,14 @@ static int dtt200u_fe_read_unc_blocks(struct dvb_frontend* fe, u32 *unc)
 static int dtt200u_fe_read_signal_strength(struct dvb_frontend* fe, u16 *strength)
 {
        struct dtt200u_fe_state *state = fe->demodulator_priv;
+       int ret;
 
        mutex_lock(&state->data_mutex);
        state->data[0] = GET_AGC;
 
-       dvb_usb_generic_rw(state->d, state->data, 1, state->data, 1, 0);
+       ret = dvb_usb_generic_rw(state->d, state->data, 1, state->data, 1, 0);
+       if (ret >= 0)
+               *strength = (state->data[0] << 8) | state->data[0];
 
        mutex_unlock(&state->data_mutex);
        return ret;
@@ -93,11 +107,14 @@ static int dtt200u_fe_read_signal_strength(struct dvb_frontend* fe, u16 *strengt
 static int dtt200u_fe_read_snr(struct dvb_frontend* fe, u16 *snr)
 {
        struct dtt200u_fe_state *state = fe->demodulator_priv;
+       int ret;
 
        mutex_lock(&state->data_mutex);
        state->data[0] = GET_SNR;
 
-       dvb_usb_generic_rw(state->d, state->data, 1, state->data, 1, 0);
+       ret = dvb_usb_generic_rw(state->d, state->data, 1, state->data, 1, 0);
+       if (ret >= 0)
+               *snr = ~((state->data[0] << 8) | state->data[0]);
 
        mutex_unlock(&state->data_mutex);
        return ret;
@@ -134,6 +151,7 @@ static int dtt200u_fe_set_frontend(struct dvb_frontend *fe)
 {
        struct dtv_frontend_properties *fep = &fe->dtv_property_cache;
        struct dtt200u_fe_state *state = fe->demodulator_priv;
+       int ret;
        u16 freq = fep->frequency / 250000;
 
        mutex_lock(&state->data_mutex);
@@ -153,12 +171,16 @@ static int dtt200u_fe_set_frontend(struct dvb_frontend *fe)
                goto ret;
        }
 
-       dvb_usb_generic_write(state->d, state->data, 2);
+       ret = dvb_usb_generic_write(state->d, state->data, 2);
+       if (ret < 0)
+               goto ret;
 
        state->data[0] = SET_RF_FREQ;
        state->data[1] = freq & 0xff;
        state->data[2] = (freq >> 8) & 0xff;
-       dvb_usb_generic_write(state->d, state->data, 3);
+       ret = dvb_usb_generic_write(state->d, state->data, 3);
+       if (ret < 0)
+               goto ret;
 
 ret:
        mutex_unlock(&state->data_mutex);