Hi,
la, 2025-08-09 kello 11:24 +0200, Paul Menzel kirjoitti:
> Dear Pauli,
>
>
> Thank you for the patch.
>
> Am 09.08.25 um 10:36 schrieb Pauli Virtanen:
> > BN == 0x00 in CIS Established means no isochronous data for the
> > corresponding direction (Core v6.1 pp. 2394). In this case SDU MTU
> > should be 0.
> >
> > However, the specification does not say the Max_PDU_C_To_P or P_To_C are
> > then zero. Intel AX210 in Framed CIS mode sets nonzero Max_PDU for
> > direction with zero BN. This causes failure later when we try to LE
> > Setup ISO Data Path for disabled direction, which is disallowed (Core
> > v6.1 pp. 2750).
> >
> > Fix by setting SDU MTU to 0 if BN == 0.
>
> Do you have command how to reproduce this on the device?
As noted in the text above, try to create framed unidirectional CIS on
this particular controller, e.g. for 44.1kHz audio.
> > Fixes: 2be22f1941d5f ("Bluetooth: hci_event: Fix parsing of CIS Established Event")
> > Signed-off-by: Pauli Virtanen <pav@xxxxxx>
> > ---
> > net/bluetooth/hci_event.c | 8 ++++----
> > 1 file changed, 4 insertions(+), 4 deletions(-)
> >
> > diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
> > index 4f0a6116291e..fe7cdd67ad2a 100644
> > --- a/net/bluetooth/hci_event.c
> > +++ b/net/bluetooth/hci_event.c
> > @@ -6745,8 +6745,8 @@ static void hci_le_cis_established_evt(struct hci_dev *hdev, void *data,
> > qos->ucast.out.latency =
> > DIV_ROUND_CLOSEST(get_unaligned_le24(ev->p_latency),
> > 1000);
> > - qos->ucast.in.sdu = le16_to_cpu(ev->c_mtu);
> > - qos->ucast.out.sdu = le16_to_cpu(ev->p_mtu);
> > + qos->ucast.in.sdu = ev->c_bn ? le16_to_cpu(ev->c_mtu) : 0;
> > + qos->ucast.out.sdu = ev->p_bn ? le16_to_cpu(ev->p_mtu) : 0;
> > qos->ucast.in.phy = ev->c_phy;
> > qos->ucast.out.phy = ev->p_phy;
> > break;
> > @@ -6760,8 +6760,8 @@ static void hci_le_cis_established_evt(struct hci_dev *hdev, void *data,
> > qos->ucast.in.latency =
> > DIV_ROUND_CLOSEST(get_unaligned_le24(ev->p_latency),
> > 1000);
> > - qos->ucast.out.sdu = le16_to_cpu(ev->c_mtu);
> > - qos->ucast.in.sdu = le16_to_cpu(ev->p_mtu);
> > + qos->ucast.out.sdu = ev->c_bn ? le16_to_cpu(ev->c_mtu) : 0;
> > + qos->ucast.in.sdu = ev->p_bn ? le16_to_cpu(ev->p_mtu) : 0;
> > qos->ucast.out.phy = ev->c_phy;
> > qos->ucast.in.phy = ev->p_phy;
> > break;
>
> Reviewed-by: Paul Menzel <pmenzel@xxxxxxxxxxxxx>
>
>
> Kind regards,
>
> Paul
