[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>

1 files changed, 31 insertions, 9 deletions

diff --git a/drivers/media/usb/dvb-usb/dtt200u-fe.c b/drivers/media/usb/dvb-usb/dtt200u-fe.c
index 7f7f64be6353..f5c042baa254 100644
--- 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);