diff options
Diffstat (limited to 'drivers/usb/typec/tcpm/tcpci.c')
| -rw-r--r-- | drivers/usb/typec/tcpm/tcpci.c | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/drivers/usb/typec/tcpm/tcpci.c b/drivers/usb/typec/tcpm/tcpci.c index c1f7073a56de..8b4ff9fff340 100644 --- a/drivers/usb/typec/tcpm/tcpci.c +++ b/drivers/usb/typec/tcpm/tcpci.c @@ -432,20 +432,30 @@ irqreturn_t tcpci_irq(struct tcpci *tcpci) if (status & TCPC_ALERT_RX_STATUS) { struct pd_message msg; - unsigned int cnt; + unsigned int cnt, payload_cnt; u16 header; regmap_read(tcpci->regmap, TCPC_RX_BYTE_CNT, &cnt); + /* + * 'cnt' corresponds to READABLE_BYTE_COUNT in section 4.4.14 + * of the TCPCI spec [Rev 2.0 Ver 1.0 October 2017] and is + * defined in table 4-36 as one greater than the number of + * bytes received. And that number includes the header. So: + */ + if (cnt > 3) + payload_cnt = cnt - (1 + sizeof(msg.header)); + else + payload_cnt = 0; tcpci_read16(tcpci, TCPC_RX_HDR, &header); msg.header = cpu_to_le16(header); - if (WARN_ON(cnt > sizeof(msg.payload))) - cnt = sizeof(msg.payload); + if (WARN_ON(payload_cnt > sizeof(msg.payload))) + payload_cnt = sizeof(msg.payload); - if (cnt > 0) + if (payload_cnt > 0) regmap_raw_read(tcpci->regmap, TCPC_RX_DATA, - &msg.payload, cnt); + &msg.payload, payload_cnt); /* Read complete, clear RX status alert bit */ tcpci_write16(tcpci, TCPC_ALERT, TCPC_ALERT_RX_STATUS); |