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From: YongSu Yoo <yongsuyoo0215@gmail.com>
Date: Thu, 11 Apr 2024 21:03:18 +0900
Message-ID: <CANXPkT4_9dkLVe8VUBaOceFRTBMqZOD=u9a1=X54TqvcOjv67A@mail.gmail.com>
Subject: Re: [PATCH] media: dvb_ca_en50221: Fix a bug for detecting CI MODULE
To: mchehab@kernel.org, yongsuyoo0215@gmail.com, v4bel@theori.io, 
	linux-media@vger.kernel.org, linux-kernel@vger.kernel.org
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Dear All

Can you review this patch ?
Can you share how this modification is going ?

2024=EB=85=84 3=EC=9B=94 8=EC=9D=BC (=EA=B8=88) =EC=98=A4=ED=9B=84 9:10, <y=
ongsuyoo0215@gmail.com>=EB=8B=98=EC=9D=B4 =EC=9E=91=EC=84=B1:
>
> From: Yongsu yoo <yongsuyoo0215@gmail.com>
>
> Signed-off-by:Yongsu Yoo <yongsuyoo0215@gmail.com>
>
> In source/drivers/media/dvb-core/dvb_ca_en50221.c, if the CA_RESET
> ioctl is called, the dvb_ca_en50221_slot_shutdown will also be called.
> Inside of the dvb_ca_en50221_slot_shutdown,
> the ca->slot_info[slot].slot_state will become DVB_CA_SLOTSTATE_NONE.
> In the most of cases, the ca->slot_info[slot].slot_state will quickly
> becomes restored to other states by the subsequent operations of the
> thread dvb_ca_en50221_thread_state_machine.
> But in some rare cases, when the CA_GET_SLOT_INFO ioctl is immediately
> called after the CA_RESET ioctl is called, the
> the ca->slot_info[slot].slot_state can still remains at
> DVB_CA_SLOTSTATE_NONE, and this causes CA_GET_SLOT_INFO ioctl not to
> return CA_CI_MODULE_PRESENT as info->flags even if CA_CI_MODULE is
> really connected on TV. This means that the CA_GET_SLOT_INFO ioctl
> does not return right informtion. This is a Bug. We fix this bug.
> ---
>  drivers/media/dvb-core/dvb_ca_en50221.c | 4 ++++
>  1 file changed, 4 insertions(+)
>
> diff --git a/drivers/media/dvb-core/dvb_ca_en50221.c b/drivers/media/dvb-=
core/dvb_ca_en50221.c
> index baf64540dc00..8d37c3c13227 100644
> --- a/drivers/media/dvb-core/dvb_ca_en50221.c
> +++ b/drivers/media/dvb-core/dvb_ca_en50221.c
> @@ -1403,6 +1403,10 @@ static int dvb_ca_en50221_io_do_ioctl(struct file =
*file,
>                     (sl->slot_state !=3D DVB_CA_SLOTSTATE_INVALID)) {
>                         info->flags =3D CA_CI_MODULE_PRESENT;
>                 }
> +               if ((sl->slot_state =3D=3D DVB_CA_SLOTSTATE_NONE) &&
> +                   (sl->camchange_type =3D=3D DVB_CA_EN50221_CAMCHANGE_I=
NSERTED)) {
> +                       info->flags =3D CA_CI_MODULE_PRESENT;
> +               }
>                 if (sl->slot_state =3D=3D DVB_CA_SLOTSTATE_RUNNING)
>                         info->flags |=3D CA_CI_MODULE_READY;
>                 break;
> --
> 2.17.1
>