Messages in this thread | | | Date | Mon, 20 Mar 2023 10:28:55 +0800 | Subject | Re: [PATCH 1/4] usb: typec: tcpm: fix cc role at port reset | From | Frank Wang <> |
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Hi Guenter,
On 2023/3/17 20:47, Guenter Roeck wrote: > 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));
To amend likes above make sense, I shall fix it later.
BR. Frank
> > Thanks, > Guenter >
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