diff options
Diffstat (limited to 'drivers/usb')
| -rw-r--r-- | drivers/usb/typec/tcpm/tcpm.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c index 4e276d2f15d1..3c6b0c8e2d3a 100644 --- a/drivers/usb/typec/tcpm/tcpm.c +++ b/drivers/usb/typec/tcpm/tcpm.c @@ -1523,7 +1523,21 @@ static bool svdm_consume_svids(struct tcpm_port *port, const u32 *p, int cnt) pmdata->svids[pmdata->nsvids++] = svid; tcpm_log(port, "SVID %d: 0x%x", pmdata->nsvids, svid); } - return true; + + /* + * PD3.0 Spec 6.4.4.3.2: The SVIDs are returned 2 per VDO (see Table + * 6-43), and can be returned maximum 6 VDOs per response (see Figure + * 6-19). If the Respondersupports 12 or more SVID then the Discover + * SVIDs Command Shall be executed multiple times until a Discover + * SVIDs VDO is returned ending either with a SVID value of 0x0000 in + * the last part of the last VDO or with a VDO containing two SVIDs + * with values of 0x0000. + * + * However, some odd dockers support SVIDs less than 12 but without + * 0x0000 in the last VDO, so we need to break the Discover SVIDs + * request and return false here. + */ + return cnt == 7; abort: tcpm_log(port, "SVID_DISCOVERY_MAX(%d) too low!", SVID_DISCOVERY_MAX); return false; |