Re: [PATCH] media: dvb_demux: Fix a bug for the continuity counter

From: YongSu Yoo
Date: Sun Apr 16 2023 - 08:02:27 EST


Hi ~ Everyone
Can you share how this patch is going ?

2023년 3월 6일 (월) 오전 6:25, <yongsuyoo0215@xxxxxxxxx>님이 작성:
>
> From: YongSu Yoo <yongsuyoo0215@xxxxxxxxx>
>
> Signed-off-by: Yongsu Yoo <yongsuyoo0215@xxxxxxxxx>
>
> In dvb_demux.c, some logics exist which compare the expected
> continuity counter and the real continuity counter. If they
> are not matched each other, both of the expected continuity
> counter and the real continuity counter should be printed.
> But there exists a bug that the expected continuity counter
> is not correctly printed. The expected continuity counter is
> replaced with the real countinuity counter + 1 so that
> the epected continuity counter is not correclty printed.
> This is wrong. This bug is fixed.
> ---
> drivers/media/dvb-core/dvb_demux.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/media/dvb-core/dvb_demux.c b/drivers/media/dvb-core/dvb_demux.c
> index 398c86279b5b..7c4d86bfdd6c 100644
> --- a/drivers/media/dvb-core/dvb_demux.c
> +++ b/drivers/media/dvb-core/dvb_demux.c
> @@ -115,12 +115,12 @@ static inline int dvb_dmx_swfilter_payload(struct dvb_demux_feed *feed,
>
> cc = buf[3] & 0x0f;
> ccok = ((feed->cc + 1) & 0x0f) == cc;
> - feed->cc = cc;
> if (!ccok) {
> set_buf_flags(feed, DMX_BUFFER_FLAG_DISCONTINUITY_DETECTED);
> dprintk_sect_loss("missed packet: %d instead of %d!\n",
> cc, (feed->cc + 1) & 0x0f);
> }
> + feed->cc = cc;
>
> if (buf[1] & 0x40) // PUSI ?
> feed->peslen = 0xfffa;
> @@ -300,7 +300,6 @@ static int dvb_dmx_swfilter_section_packet(struct dvb_demux_feed *feed,
>
> cc = buf[3] & 0x0f;
> ccok = ((feed->cc + 1) & 0x0f) == cc;
> - feed->cc = cc;
>
> if (buf[3] & 0x20) {
> /* adaption field present, check for discontinuity_indicator */
> @@ -336,6 +335,7 @@ static int dvb_dmx_swfilter_section_packet(struct dvb_demux_feed *feed,
> feed->pusi_seen = false;
> dvb_dmx_swfilter_section_new(feed);
> }
> + feed->cc = cc;
>
> if (buf[1] & 0x40) {
> /* PUSI=1 (is set), section boundary is here */
> --
> 2.17.1
>