[2/2] media: dvb-usb-v2: lmedm04: move ts2020 attach to dm04_lme2510_tuner

  When the tuner was split from m88rs2000 the attach function is in wrong
place.

Move to dm04_lme2510_tuner to trap errors on failure and removing
a call to lme_coldreset.

Prevents driver starting up without any tuner connected.

Fixes to trap for ts2020 fail.
LME2510(C): FE Found M88RS2000
ts2020: probe of 0-0060 failed with error -11
...
LME2510(C): TUN Found RS2000 tuner
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN

Reported-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
---
 drivers/media/usb/dvb-usb-v2/lmedm04.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)
  

On Tue, Sep 26, 2017 at 11:10 PM, Malcolm Priestley <tvboxspy@gmail.com> wrote:
> When the tuner was split from m88rs2000 the attach function is in wrong
> place.
>
> Move to dm04_lme2510_tuner to trap errors on failure and removing
> a call to lme_coldreset.
>
> Prevents driver starting up without any tuner connected.
>
> Fixes to trap for ts2020 fail.
> LME2510(C): FE Found M88RS2000
> ts2020: probe of 0-0060 failed with error -11
> ...
> LME2510(C): TUN Found RS2000 tuner
> kasan: CONFIG_KASAN_INLINE enabled
> kasan: GPF could be caused by NULL-ptr deref or user memory access
> general protection fault: 0000 [#1] PREEMPT SMP KASAN
>
> Reported-by: Andrey Konovalov <andreyknvl@google.com>
> Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>

Tested-by: Andrey Konovalov <andreyknvl@google.com>

These 2 patches fix the crash with the reproducer that I have.

Thanks!

> ---
>  drivers/media/usb/dvb-usb-v2/lmedm04.c | 13 ++++++-------
>  1 file changed, 6 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/media/usb/dvb-usb-v2/lmedm04.c b/drivers/media/usb/dvb-usb-v2/lmedm04.c
> index 992f2011a6ba..be26c029546b 100644
> --- a/drivers/media/usb/dvb-usb-v2/lmedm04.c
> +++ b/drivers/media/usb/dvb-usb-v2/lmedm04.c
> @@ -1076,8 +1076,6 @@ static int dm04_lme2510_frontend_attach(struct dvb_usb_adapter *adap)
>
>                 if (adap->fe[0]) {
>                         info("FE Found M88RS2000");
> -                       dvb_attach(ts2020_attach, adap->fe[0], &ts2020_config,
> -                                       &d->i2c_adap);
>                         st->i2c_tuner_gate_w = 5;
>                         st->i2c_tuner_gate_r = 5;
>                         st->i2c_tuner_addr = 0x60;
> @@ -1143,17 +1141,18 @@ static int dm04_lme2510_tuner(struct dvb_usb_adapter *adap)
>                         ret = st->tuner_config;
>                 break;
>         case TUNER_RS2000:
> -               ret = st->tuner_config;
> +               if (dvb_attach(ts2020_attach, adap->fe[0],
> +                              &ts2020_config, &d->i2c_adap))
> +                       ret = st->tuner_config;
>                 break;
>         default:
>                 break;
>         }
>
> -       if (ret)
> +       if (ret) {
>                 info("TUN Found %s tuner", tun_msg[ret]);
> -       else {
> -               info("TUN No tuner found --- resetting device");
> -               lme_coldreset(d);
> +       } else {
> +               info("TUN No tuner found");
>                 return -ENODEV;
>         }
>
> --
> 2.14.1
>