Hi Guenter,
On 2023/3/20 11:35, Guenter Roeck wrote:
On Mon, Mar 20, 2023 at 10:38:35AM +0800, Frank Wang wrote:
Hi Guenter,
On 2023/3/17 20:58, Guenter Roeck wrote:
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
The story goes like this, the fusb302 notified SOFT_RESET completion to
TCPM and began to receive the Source Caps automatically,
TCPM got completion from fusb302 and changed state to SNK_WAIT_CAPABILITIES
and invoked set_pd_rx() callback. However, the
fusb302 or TCPM's worker may be not scheduled in time, set_pd_rx() would be
performed after the Source Caps packets had received
into fusb302's FIFO, even after the GoodCRC (Source Caps) had be replied.
Yes, but the fusb302 driver clears its fifo in the set_pd_rx() callback.
I see that as a problem in the fusb302 driver( it could clear its fifo when
it notifies the TCPM that soft reset is complete, for example), and I am
hesitant to work around that problem in the tcpm code.
Guenter
Okay, I shall abandon this from the series.
BR.
Frank
So make forward set_pd_rx() process before PD_CTRL_SOFT_RESET sent at
SOFT_RESET_SEND state can cleanup the context in our side
and ensure the right PD commucation. I am not sure whether it is sensible?
BR.
Frank
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@xxxxxxxxxxxxxx>
---
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
--
底层平台部 王明成（Frank Wang）
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