Dear All Can you share how this patch is going ? 2022년 8월 18일 (목) 오후 9:50, YongSu Yoo <yongsuyoo0215@xxxxxxxxx>님이 작성: > > Signed-off-by:Yongsu Yoo <yongsuyoo0215@xxxxxxxxx> > > The function of "dvb_ca_en50221_write_data" at source/drivers/media > /dvb-core/dvb_ca_en50221.c is used for two cases. > The first case is for writing APDU data in the function of > "dvb_ca_en50221_io_write" at source/drivers/media/dvb-core/ > dvb_ca_en50221.c. > The second case is for writing the host link buf size on the > Command Register in the function of "dvb_ca_en50221_link_init" > at source/drivers/media/dvb-core/dvb_ca_en50221.c. > In the second case, there exists a bug like followings. > In the function of the "dvb_ca_en50221_link_init", > after a TV host calculates the host link buf_size, > the TV host writes the calculated host link buf_size on the > Size Register. > Accroding to the en50221 Spec (the page 60 of > https://dvb.org/wp-content/uploads/2020/02/En50221.V1.pdf), > before this writing operation, the "SW(CMDREG_SW)" flag in the > Command Register should be set. We can see this setting operation > in the function of the "dvb_ca_en50221_link_init" like below. > ... > if ((ret = ca->pub->write_cam_control(ca->pub, slot, > CTRLIF_COMMAND, IRQEN | CMDREG_SW)) != 0) > return ret; > ... > But, after that, the real writing operation is implemented using > the function of the "dvb_ca_en50221_write_data" in the function of > "dvb_ca_en50221_link_init", and the "dvb_ca_en50221_write_data" > includes the function of "ca->pub->write_cam_control", > and the function of the "ca->pub->write_cam_control" in the > function of the "dvb_ca_en50221_wrte_data" does not include > "CMDREG_SW" flag like below. > ... > if ((status = ca->pub->write_cam_control(ca->pub, slot, > CTRLIF_COMMAND, IRQEN | CMDREG_HC)) != 0) > ... > In the above source code, we can see only the "IRQEN | CMDREG_HC", > but we cannot see the "CMDREG_SW". > The "CMDREG_SW" flag which was set in the function of the > "dvb_ca_en50221_link_init" was rollbacked by the follwoing function > of the "dvb_ca_en50221_write_data". > This is a bug. and this bug causes that the calculated host link buf_size > is not properly written in the CI module. > Through this patch, we fix this bug. > --- > drivers/media/dvb-core/dvb_ca_en50221.c | 12 +++++++----- > 1 file changed, 7 insertions(+), 5 deletions(-) > > diff --git a/drivers/media/dvb-core/dvb_ca_en50221.c b/drivers/media/dvb-core/dvb_ca_en50221.c > index 15a08d8c69ef..13f249b0a080 100644 > --- a/drivers/media/dvb-core/dvb_ca_en50221.c > +++ b/drivers/media/dvb-core/dvb_ca_en50221.c > @@ -187,7 +187,7 @@ static void dvb_ca_en50221_thread_wakeup(struct dvb_ca_private *ca); > static int dvb_ca_en50221_read_data(struct dvb_ca_private *ca, int slot, > u8 *ebuf, int ecount); > static int dvb_ca_en50221_write_data(struct dvb_ca_private *ca, int slot, > - u8 *ebuf, int ecount); > + u8 *ebuf, int ecount, int size_write_flag); > > /** > * findstr - Safely find needle in haystack. > @@ -370,7 +370,7 @@ static int dvb_ca_en50221_link_init(struct dvb_ca_private *ca, int slot) > ret = dvb_ca_en50221_wait_if_status(ca, slot, STATUSREG_FR, HZ / 10); > if (ret) > return ret; > - ret = dvb_ca_en50221_write_data(ca, slot, buf, 2); > + ret = dvb_ca_en50221_write_data(ca, slot, buf, 2, CMDREG_SW); > if (ret != 2) > return -EIO; > ret = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_COMMAND, IRQEN); > @@ -778,11 +778,13 @@ static int dvb_ca_en50221_read_data(struct dvb_ca_private *ca, int slot, > * @buf: The data in this buffer is treated as a complete link-level packet to > * be written. > * @bytes_write: Size of ebuf. > + * @size_write_flag: A flag on Command Register which says whether the link size > + * information will be writen or not. > * > * return: Number of bytes written, or < 0 on error. > */ > static int dvb_ca_en50221_write_data(struct dvb_ca_private *ca, int slot, > - u8 *buf, int bytes_write) > + u8 *buf, int bytes_write, int size_write_flag) > { > struct dvb_ca_slot *sl = &ca->slot_info[slot]; > int status; > @@ -817,7 +819,7 @@ static int dvb_ca_en50221_write_data(struct dvb_ca_private *ca, int slot, > > /* OK, set HC bit */ > status = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_COMMAND, > - IRQEN | CMDREG_HC); > + IRQEN | CMDREG_HC | size_write_flag); > if (status) > goto exit; > > @@ -1508,7 +1510,7 @@ static ssize_t dvb_ca_en50221_io_write(struct file *file, > > mutex_lock(&sl->slot_lock); > status = dvb_ca_en50221_write_data(ca, slot, fragbuf, > - fraglen + 2); > + fraglen + 2, 0); > mutex_unlock(&sl->slot_lock); > if (status == (fraglen + 2)) { > written = 1; > -- > 2.17.1 >
