Jun Li <jun...@nxp.com> 於 2020年10月9日 週五 下午2:12寫道: > > > > > -----Original Message----- > > From: ChiYuan Huang <u0084...@gmail.com> > > Sent: Wednesday, October 7, 2020 6:13 PM > > To: Jun Li <lijun.ker...@gmail.com> > > Cc: Guenter Roeck <li...@roeck-us.net>; Greg KH > > <gre...@linuxfoundation.org>; Heikki Krogerus > > <heikki.kroge...@linux.intel.com>; Linux USB List > > <linux-...@vger.kernel.org>; lkml <linux-kernel@vger.kernel.org>; > > cy_huang <cy_hu...@richtek.com>; Jun Li <jun...@nxp.com> > > Subject: Re: [PATCH] usb: typec: tcpm: Fix if vbus before cc, > > hard_reset_count > > not reset issue > > > > ChiYuan Huang <u0084...@gmail.com> 於 2020年10月7日 週三 上午1:39寫道: > > > > > > Jun Li <lijun.ker...@gmail.com> 於 2020年10月7日 週三 上午12:52寫道: > > > > > > > > ChiYuan Huang <u0084...@gmail.com> 于2020年10月6日周二 下午12:38写 > > 道: > > > > > > > > > > Guenter Roeck <li...@roeck-us.net> 於 2020年10月5日 週一 下午11:30 > > 寫道: > > > > > > > > > > > > On 10/5/20 4:08 AM, Greg KH wrote: > > > > > > [ ... ] > > > > > > >>> What ever happened with this patch, is there still disagreement? > > > > > > >>> > > > > > > >> > > > > > > >> Yes, there is. I wouldn't have added the conditional without > > > > > > >> reason, and I am concerned that removing it entirely will open > > another problem. > > > > > > >> Feel free to apply, though - I can't prove that my concern is > > > > > > >> valid, and after all we'll get reports from the field later if > > it is. > > > > > > > > > > > > > > Ok, can I get an ack so I know who to come back to in the > > > > > > > future if there are issues? :) > > > > > > > > > > > > > > > > > > > Not from me, for the reasons I stated. I would be ok with something > > like: > > > > > > > > > > > > - if (tcpm_port_is_disconnected(port)) > > > > > > + if (tcpm_port_is_disconnected(port) || > > > > > > + (tcpm_cc_is_open(port->cc1) && > > > > > > + tcpm_cc_is_open(port->cc2))) > > > > > > > > > > > > to narrow down the condition. > > > > > > > > > > I have tried the above comment and It doesn't work. > > > > > How about to change the judgement like as below > > > > > > > > > > - if (tcpm_port_is_disconnected(port)) > > > > > + if (tcpm_port_is_disconnected(port) || > > > > > + !port->vbus_present) > > > > > > > > > > The hard_reset_count not reset issue is following by the below > > > > > order 1. VBUS off ( at the same time, cc is still detected as > > > > > attached) > > > > > port->attached become false and cc is not open > > > > > 2. After that, cc detached. > > > > > due to port->attached is false, tcpm_detach() directly return. > > > > > > > > If tcpm_detach() return directly, then how your patch can reset > > > > hard_reset_count? > > > > > > > Yes, it can. We know vbus_present change from true to false and cc > > > detach both trigger tcpm_detach. > > > My change is whenever tcpm_detach to be called, hard_reset_count will > > > be reset to zero. > > > > > > > I am seeing the same issue on my platform, the proposed change: > > > > - if (tcpm_port_is_disconnected(port)) > > > > - port->hard_reset_count = 0; > > > > + port->hard_reset_count = 0; > > > > can't resolve it on my platform. > > > > > > > I'm not sure what's your condition. Could you directly paste the tcpm > > > log for the check? > > > > How about reset hard_reset_count in SNK_READY? > > > > @@ -3325,6 +3329,7 @@ static void run_state_machine(struct tcpm_port > > *port) > > > > case SNK_READY: > > > > port->try_snk_count = 0; > > > > port->update_sink_caps = false; > > > > + port->hard_reset_count = 0; > > > > if (port->explicit_contract) { > > > > typec_set_pwr_opmode(port->typec_port, > > > > TYPEC_PWR_MODE_PD); > > > > > > > > can this resolve your problem? > > > I'm not sure. It need to have a try, then I can answer you. > > > But from USBPD spec, the hard_reset_count need to reset zero only when > > > 1. At src state, pe_src_send_cap and receive GoodCRC 2. At snk state, > > > pe_snk_evaluate_cap need to reset hard_reset_count > > 3. > 8.3.3.3.8 PE_SNK_Hard_Reset state > "Note: The HardResetCounter is reset on a power cycle or Detach." > > > > > > > > > Li Jun > > > > > > > > > > And that's why hard_reset_count is not reset to 0. > > > > I tried in snk_ready to reset hard_reset_count. > > At normal case, it works. > > But it seems still the possible fail case like as below. > > 200ms -> cc debounce max time > > 240ms -> snk_waitcap max time > > If the plugin/out period is between (200+240) and (200+ 2* 240)ms , and the > > src side plug out like as the described scenario. > > From this case, hard_reset_count may still 1. > > And we expect the next plugin hard_reset_count is 0. But not, actually it > > never reset. > > So at next plugin, only one hard_reset will be sent and reach > > hard_reset_count > > max (2). > > > > This case is hard to reproduce. But actually it's possible. > > Make sense. > > Then I propose doing this at SNK_UNATTACHED > @@ -3156,6 +3156,7 @@ static void run_state_machine(struct tcpm_port *port) > if (!port->non_pd_role_swap) > tcpm_swap_complete(port, -ENOTCONN); > tcpm_pps_complete(port, -ENOTCONN); > + port->hard_reset_count = 0; > tcpm_snk_detach(port); > if (tcpm_start_toggling(port, TYPEC_CC_RD)) { > tcpm_set_state(port, TOGGLING, 0); > Li Jun
For the current power role is snk, I think it may work. How about the src role? src role only reset the hard_reset_count in tcpm_detach and src_ready state? I check the flow that you mentioned in the previous mail. It's really a special case from any state to port_reset. If the case is considered, how about to reset the hard_reset_count and don't care the port is attached or not in tcpm_detach function like as below. @@ -2789,6 +2789,8 @@ static void tcpm_reset_port(struct tcpm_port *port) static void tcpm_detach(struct tcpm_port *port) { + port->hard_reset_count = 0; + if (!port->attached) return; @@ -2797,9 +2799,6 @@ static void tcpm_detach(struct tcpm_port *port) port->tcpc->set_bist_data(port->tcpc, false); } - if (tcpm_port_is_disconnected(port)) - port->hard_reset_count = 0; - tcpm_reset_port(port); } Like I mentioned before, whatever the condition is, hard_reset_count must be reset to zero during tcpm_detach. But refer to Guenter's mail, he prefer to narrow down the condition to reset this counter. I think the original thought is important why to put this line there. Hi, Guenter: From the discussion, we really need to know why you put the reset line below port attached is false and also make some judgement. I think there may be ome condition that we don't considered. > > > > > > > > > > > > > > > Guenter