Messages in this thread | ![/](/images/icornerl.gif) | | Date | Fri, 17 Mar 2023 05:47:10 -0700 | From | Guenter Roeck <> | Subject | Re: [PATCH 1/4] usb: typec: tcpm: fix cc role at port reset |
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On 3/17/23 04:24, Heikki Krogerus wrote: > On Wed, Mar 15, 2023 at 10:55:20AM +0800, Frank Wang wrote: >> Hi Heikki, >> >> On 2023/3/14 17:20, Heikki Krogerus wrote: >>> On Mon, Mar 13, 2023 at 10:58:40AM +0800, Frank Wang wrote: >>>> In the current implementation, the tcpm set CC1/CC2 role to open when >>>> it do port reset would cause the VBUS removed by the Type-C partner. >>>> >>>> The Figure 4-20 in the TCPCI 2.0 specification show that the CC1/CC2 >>>> role should set to 01b (Rp) or 10b (Rd) at Power On or Reset stage >>>> in DRP initialization and connection detection. >>>> >>>> So set CC1/CC2 to Rd to fix it. >>>> >>>> Signed-off-by: Frank Wang <frank.wang@rock-chips.com> >>>> --- >>>> drivers/usb/typec/tcpm/tcpm.c | 2 +- >>>> 1 file changed, 1 insertion(+), 1 deletion(-) >>>> >>>> diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c >>>> index a0d943d785800..66de02a56f512 100644 >>>> --- a/drivers/usb/typec/tcpm/tcpm.c >>>> +++ b/drivers/usb/typec/tcpm/tcpm.c >>>> @@ -4851,7 +4851,7 @@ static void run_state_machine(struct tcpm_port *port) >>>> break; >>>> case PORT_RESET: >>>> tcpm_reset_port(port); >>>> - tcpm_set_cc(port, TYPEC_CC_OPEN); >>>> + tcpm_set_cc(port, TYPEC_CC_RD); >>>> tcpm_set_state(port, PORT_RESET_WAIT_OFF, >>>> PD_T_ERROR_RECOVERY); >>>> break; >>> Will this work if the port is for example source only? >> >> Yeah, this only set at port reset stage and CC value will be set again >> (Rd for Sink, Rp_* for Source) when start toggling. > > Okay. Let's wait for comments from Guenter. >
Figure 4-20 is specifically for dual role ports. Also, start toggling would not happen if the low level driver doesn't have a start_toggling callback. I think this may require some tweaking based on the port type or, rather, tcpm_default_state(). Something like
tcpm_set_cc(port, tcpm_default_state(port) == SNK_UNATTACHED ? TYPEC_CC_RD : tcpm_rp_cc(port));
Thanks, Guenter
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