Messages in this thread | | | Date | Wed, 15 Mar 2023 10:57:37 +0800 | Subject | Re: [PATCH 2/4] usb: typec: tcpm: fix multiple times discover svids error | From | Frank Wang <> |
| |
Hi Heikki,
On 2023/3/14 17:22, Heikki Krogerus wrote: > On Mon, Mar 13, 2023 at 10:58:41AM +0800, Frank Wang wrote: >> PD3.0 Spec 6.4.4.3.2 say that only Responder supports 12 or more SVIDs, >> 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. >> >> In the current implementation, if the last VDO does not find that the >> Discover SVIDs Command would be executed multiple times even if the >> Responder SVIDs are less than 12, and we found some odd dockers just >> meet this case. So fix it. >> >> Signed-off-by: Frank Wang <frank.wang@rock-chips.com> >> --- >> drivers/usb/typec/tcpm/tcpm.c | 16 +++++++++++++++- >> 1 file changed, 15 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c >> index 66de02a56f512..2962f7c261976 100644 >> --- a/drivers/usb/typec/tcpm/tcpm.c >> +++ b/drivers/usb/typec/tcpm/tcpm.c >> @@ -1515,7 +1515,21 @@ 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 ? true : false; > return cnt == 7
Okay, next to fix it.
BR. Frank
| |