[PATCH v2 14/31] dtt200u-fe: handle errors on USB control messages

From: Mauro Carvalho Chehab
Date: Tue Oct 11 2016 - 06:13:34 EST


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

Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxxx>
---
drivers/media/usb/dvb-usb/dtt200u-fe.c | 40 ++++++++++++++++++++++++++--------
1 file 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);
--
2.7.4