diff options
| -rw-r--r-- | net/nfc/digital_dep.c | 71 |
1 files changed, 43 insertions, 28 deletions
diff --git a/net/nfc/digital_dep.c b/net/nfc/digital_dep.c index 1778c23751d4..e0268777ab18 100644 --- a/net/nfc/digital_dep.c +++ b/net/nfc/digital_dep.c @@ -1141,49 +1141,64 @@ static void digital_tg_recv_dep_req(struct nfc_digital_dev *ddev, void *arg, rc = 0; break; case DIGITAL_NFC_DEP_PFB_ACK_NACK_PDU: - if (!DIGITAL_NFC_DEP_NACK_BIT_SET(pfb)) { /* ACK */ - if ((ddev->atn_count && - (DIGITAL_NFC_DEP_PFB_PNI(pfb - 1) != - ddev->curr_nfc_dep_pni)) || - (DIGITAL_NFC_DEP_PFB_PNI(pfb) != - ddev->curr_nfc_dep_pni) || - !ddev->chaining_skb || !ddev->saved_skb) { + if (DIGITAL_NFC_DEP_NACK_BIT_SET(pfb)) { /* NACK */ + if (DIGITAL_NFC_DEP_PFB_PNI(pfb + 1) != + ddev->curr_nfc_dep_pni) { rc = -EIO; goto exit; } - if (ddev->atn_count) { - ddev->atn_count = 0; + ddev->atn_count = 0; + + rc = digital_tg_send_saved_skb(ddev); + if (rc) + goto exit; + + goto free_resp; + } + + /* ACK */ + if (ddev->atn_count) { + /* The target has previously recevied one or more ATN + * PDUs. + */ + ddev->atn_count = 0; + /* If the ACK PNI is equal to the target PNI - 1 means + * that the initiator did not receive the previous PDU + * sent by the target so re-send it. + */ + if (DIGITAL_NFC_DEP_PFB_PNI(pfb + 1) == + ddev->curr_nfc_dep_pni) { rc = digital_tg_send_saved_skb(ddev); if (rc) goto exit; - return; + goto free_resp; } - kfree_skb(ddev->saved_skb); - ddev->saved_skb = NULL; + /* Otherwise, the target did not receive the previous + * ACK PDU from the initiator. Fallback to normal + * processing of chained PDU then. + */ + } - rc = digital_tg_send_dep_res(ddev, ddev->chaining_skb); - if (rc) - goto exit; - } else { /* NACK */ - if ((DIGITAL_NFC_DEP_PFB_PNI(pfb + 1) != - ddev->curr_nfc_dep_pni) || - !ddev->saved_skb) { - rc = -EIO; - goto exit; - } + /* Keep on sending chained PDU */ + if (!ddev->chaining_skb || + DIGITAL_NFC_DEP_PFB_PNI(pfb) != + ddev->curr_nfc_dep_pni) { + rc = -EIO; + goto exit; + } - ddev->atn_count = 0; + kfree_skb(ddev->saved_skb); + ddev->saved_skb = NULL; - rc = digital_tg_send_saved_skb(ddev); - if (rc) - goto exit; - } + rc = digital_tg_send_dep_res(ddev, ddev->chaining_skb); + if (rc) + goto exit; - return; + goto free_resp; case DIGITAL_NFC_DEP_PFB_SUPERVISOR_PDU: if (DIGITAL_NFC_DEP_PFB_IS_TIMEOUT(pfb)) { rc = -EINVAL; |