Messages in this thread | | | Date | Fri, 17 Mar 2023 05:58:06 -0700 | Subject | Re: [PATCH 4/4] usb: typec: tcpm: fix source caps may lost after soft reset | From | Guenter Roeck <> |
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On 3/12/23 19:58, Frank Wang wrote: > Invoke set_pd_rx() may flush the RX FIFO of PD controller, so do > set_pd_rx() before sending Soft Reset in case Source caps may be flushed > at debounce time between SOFT_RESET_SEND and SNK_WAIT_CAPABILITIES state. >
Isn't that a problem of the fusb302 driver that it flushes its buffers unconditionally when its set_pd_rx() callback is called ?
Guenter
> Without this patch, in PD charger stress test, the FUSB302 driver may > occur the following exceptions in power negotiation stage. > > [ ...] > [ 4.512252] fusb302_irq_intn > [ 4.512260] AMS SOFT_RESET_AMS finished > [ 4.512269] state change SOFT_RESET_SEND ->SNK_WAIT_CAPABILITIES [rev3 NONE_AMS] > [ 4.514511] pd := on > [ 4.514516] pending state change SNK_WAIT_CAPABILITIES ->HARD_RESET_SEND @ 310 ms [rev3 NONE_AMS] > [ 4.515428] IRQ: 0x51, a: 0x00, b: 0x01, status0: 0x93 > [ 4.515431] IRQ: BC_LVL, handler pending > [ 4.515435] IRQ: PD sent good CRC > [ 4.516434] PD message header: 0 > [ 4.516437] PD message len: 0 > [ 4.516444] PD RX, header: 0x0 [1] > > Signed-off-by: Frank Wang <frank.wang@rock-chips.com> > --- > drivers/usb/typec/tcpm/tcpm.c | 11 +++++++---- > 1 file changed, 7 insertions(+), 4 deletions(-) > > diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c > index 9e583060e64fc..ba6bf71838eed 100644 > --- a/drivers/usb/typec/tcpm/tcpm.c > +++ b/drivers/usb/typec/tcpm/tcpm.c > @@ -4321,10 +4321,12 @@ static void run_state_machine(struct tcpm_port *port) > tcpm_set_state(port, unattached_state(port), 0); > break; > case SNK_WAIT_CAPABILITIES: > - ret = port->tcpc->set_pd_rx(port->tcpc, true); > - if (ret < 0) { > - tcpm_set_state(port, SNK_READY, 0); > - break; > + if (port->prev_state != SOFT_RESET_SEND) { > + ret = port->tcpc->set_pd_rx(port->tcpc, true); > + if (ret < 0) { > + tcpm_set_state(port, SNK_READY, 0); > + break; > + } > } > /* > * If VBUS has never been low, and we time out waiting > @@ -4603,6 +4605,7 @@ static void run_state_machine(struct tcpm_port *port) > case SOFT_RESET_SEND: > port->message_id = 0; > port->rx_msgid = -1; > + port->tcpc->set_pd_rx(port->tcpc, true); > if (tcpm_pd_send_control(port, PD_CTRL_SOFT_RESET)) > tcpm_set_state_cond(port, hard_reset_state(port), 0); > else
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