diff options
Diffstat (limited to 'drivers/platform/surface/aggregator/ssh_packet_layer.c')
| -rw-r--r-- | drivers/platform/surface/aggregator/ssh_packet_layer.c | 24 |
1 files changed, 20 insertions, 4 deletions
diff --git a/drivers/platform/surface/aggregator/ssh_packet_layer.c b/drivers/platform/surface/aggregator/ssh_packet_layer.c index 6748fe4ac5d5..def8d7ac541f 100644 --- a/drivers/platform/surface/aggregator/ssh_packet_layer.c +++ b/drivers/platform/surface/aggregator/ssh_packet_layer.c @@ -1596,16 +1596,32 @@ static void ssh_ptl_timeout_reap(struct work_struct *work) ssh_ptl_tx_wakeup_packet(ptl); } -static bool ssh_ptl_rx_retransmit_check(struct ssh_ptl *ptl, u8 seq) +static bool ssh_ptl_rx_retransmit_check(struct ssh_ptl *ptl, const struct ssh_frame *frame) { int i; /* + * Ignore unsequenced packets. On some devices (notably Surface Pro 9), + * unsequenced events will always be sent with SEQ=0x00. Attempting to + * detect retransmission would thus just block all events. + * + * While sequence numbers would also allow detection of retransmitted + * packets in unsequenced communication, they have only ever been used + * to cover edge-cases in sequenced transmission. In particular, the + * only instance of packets being retransmitted (that we are aware of) + * is due to an ACK timeout. As this does not happen in unsequenced + * communication, skip the retransmission check for those packets + * entirely. + */ + if (frame->type == SSH_FRAME_TYPE_DATA_NSQ) + return false; + + /* * Check if SEQ has been seen recently (i.e. packet was * re-transmitted and we should ignore it). */ for (i = 0; i < ARRAY_SIZE(ptl->rx.blocked.seqs); i++) { - if (likely(ptl->rx.blocked.seqs[i] != seq)) + if (likely(ptl->rx.blocked.seqs[i] != frame->seq)) continue; ptl_dbg(ptl, "ptl: ignoring repeated data packet\n"); @@ -1613,7 +1629,7 @@ static bool ssh_ptl_rx_retransmit_check(struct ssh_ptl *ptl, u8 seq) } /* Update list of blocked sequence IDs. */ - ptl->rx.blocked.seqs[ptl->rx.blocked.offset] = seq; + ptl->rx.blocked.seqs[ptl->rx.blocked.offset] = frame->seq; ptl->rx.blocked.offset = (ptl->rx.blocked.offset + 1) % ARRAY_SIZE(ptl->rx.blocked.seqs); @@ -1624,7 +1640,7 @@ static void ssh_ptl_rx_dataframe(struct ssh_ptl *ptl, const struct ssh_frame *frame, const struct ssam_span *payload) { - if (ssh_ptl_rx_retransmit_check(ptl, frame->seq)) + if (ssh_ptl_rx_retransmit_check(ptl, frame)) return; ptl->ops.data_received(ptl, payload); |