On Fri,  7 Oct 2016 14:24:15 -0300
Mauro Carvalho Chehab <mche...@s-opensource.com> wrote:

> The USB control messages require DMA to work. We cannot pass
> a stack-allocated buffer, as it is not warranted that the
> stack would be into a DMA enabled area.
> 
> Signed-off-by: Mauro Carvalho Chehab <mche...@s-opensource.com>
> ---
>  drivers/media/usb/dvb-usb/cinergyT2-fe.c | 45
> ++++++++++++++++---------------- 1 file changed, 23 insertions(+), 22
> deletions(-)
> 
> diff --git a/drivers/media/usb/dvb-usb/cinergyT2-fe.c
> b/drivers/media/usb/dvb-usb/cinergyT2-fe.c index
> fd8edcb56e61..03ba66ef1f28 100644 ---
> a/drivers/media/usb/dvb-usb/cinergyT2-fe.c +++
> b/drivers/media/usb/dvb-usb/cinergyT2-fe.c @@ -139,6 +139,9 @@ static
> uint16_t compute_tps(struct dtv_frontend_properties *op) struct
> cinergyt2_fe_state { struct dvb_frontend fe;
>       struct dvb_usb_device *d;
> +
> +     unsigned char data[64];
> +
>       struct dvbt_get_status_msg status;
>  };
>  
> @@ -146,28 +149,28 @@ static int cinergyt2_fe_read_status(struct
> dvb_frontend *fe, enum fe_status *status)
>  {
>       struct cinergyt2_fe_state *state = fe->demodulator_priv;
> -     struct dvbt_get_status_msg result;
> -     u8 cmd[] = { CINERGYT2_EP1_GET_TUNER_STATUS };
>       int ret;
>  
> -     ret = dvb_usb_generic_rw(state->d, cmd, sizeof(cmd), (u8
> *)&result,
> -                     sizeof(result), 0);
> +     state->data[0] = CINERGYT2_EP1_GET_TUNER_STATUS;
> +
> +     ret = dvb_usb_generic_rw(state->d, state->data, 1,
> +                              state->data, sizeof(state->status),
> 0); if (ret < 0)
>               return ret;
>  
> -     state->status = result;
> +     memcpy(&state->status, state->data, sizeof(state->status));
>  
>       *status = 0;
>  
> -     if (0xffff - le16_to_cpu(result.gain) > 30)
> +     if (0xffff - le16_to_cpu(state->status.gain) > 30)
>               *status |= FE_HAS_SIGNAL;
> -     if (result.lock_bits & (1 << 6))
> +     if (state->status.lock_bits & (1 << 6))
>               *status |= FE_HAS_LOCK;
> -     if (result.lock_bits & (1 << 5))
> +     if (state->status.lock_bits & (1 << 5))
>               *status |= FE_HAS_SYNC;
> -     if (result.lock_bits & (1 << 4))
> +     if (state->status.lock_bits & (1 << 4))
>               *status |= FE_HAS_CARRIER;
> -     if (result.lock_bits & (1 << 1))
> +     if (state->status.lock_bits & (1 << 1))
>               *status |= FE_HAS_VITERBI;
>  
>       if ((*status & (FE_HAS_CARRIER | FE_HAS_VITERBI |
> FE_HAS_SYNC)) != @@ -232,31 +235,29 @@ static int
> cinergyt2_fe_set_frontend(struct dvb_frontend *fe) {
>       struct dtv_frontend_properties *fep =
> &fe->dtv_property_cache; struct cinergyt2_fe_state *state =
> fe->demodulator_priv;
> -     struct dvbt_set_parameters_msg param;
> -     char result[2];
> +     struct dvbt_set_parameters_msg *param = (void *)state->data;
>       int err;
>  
> -     param.cmd = CINERGYT2_EP1_SET_TUNER_PARAMETERS;
> -     param.tps = cpu_to_le16(compute_tps(fep));
> -     param.freq = cpu_to_le32(fep->frequency / 1000);
> -     param.flags = 0;
> +     param->cmd = CINERGYT2_EP1_SET_TUNER_PARAMETERS;
> +     param->tps = cpu_to_le16(compute_tps(fep));
> +     param->freq = cpu_to_le32(fep->frequency / 1000);
> +     param->flags = 0;
>  
>       switch (fep->bandwidth_hz) {
>       default:
>       case 8000000:
> -             param.bandwidth = 8;
> +             param->bandwidth = 8;
>               break;
>       case 7000000:
> -             param.bandwidth = 7;
> +             param->bandwidth = 7;
>               break;
>       case 6000000:
> -             param.bandwidth = 6;
> +             param->bandwidth = 6;
>               break;
>       }
>  
> -     err = dvb_usb_generic_rw(state->d,
> -                     (char *)&param, sizeof(param),
> -                     result, sizeof(result), 0);
> +     err = dvb_usb_generic_rw(state->d, state->data,
> sizeof(*param),
> +                              state->data, 2, 0);
>       if (err < 0)
>               err("cinergyt2_fe_set_frontend() Failed! err=%d\n",
> err); 

Reviewed-By: Patrick Boettcher <patrick.boettc...@posteo.de>
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