Messages in this thread | | | Date | Mon, 18 Sep 2023 20:48:44 +0530 | Subject | Re: usb: typec: ucsi: Clear EVENT_PENDING bit if ucsi_send_command fails | From | Prashanth K <> |
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On 18-09-23 07:55 pm, Heikki Krogerus wrote: > On Sat, Sep 16, 2023 at 01:58:30PM +0530, Prashanth K wrote: >> >> >> On 15-09-23 07:27 pm, Heikki Krogerus wrote: >>> Hi Prashanth, >>> >>> On Fri, Sep 15, 2023 at 07:10:25PM +0530, Prashanth K wrote: >>>> On 15-09-23 06:02 pm, Heikki Krogerus wrote: >>>>> On Tue, Sep 12, 2023 at 04:37:47PM +0530, Prashanth K wrote: >>>>>> >>>>>> >>>>>> On 11-09-23 06:19 pm, Heikki Krogerus wrote: >>>>>>> On Mon, Sep 11, 2023 at 02:34:15PM +0530, Prashanth K wrote: >>>>>>>> Currently if ucsi_send_command() fails, then we bail out without >>>>>>>> clearing EVENT_PENDING flag. So when the next connector change >>>>>>>> event comes, ucsi_connector_change() won't queue the con->work, >>>>>>>> because of which none of the new events will be processed. >>>>>>>> >>>>>>>> Fix this by clearing EVENT_PENDING flag if ucsi_send_command() >>>>>>>> fails. >>>>>>>> >>>>>>>> Cc: <stable@vger.kernel.org> # 5.16 >>>>>>>> Fixes: 512df95b9432 ("usb: typec: ucsi: Better fix for missing unplug events issue") >>>>>>>> Signed-off-by: Prashanth K <quic_prashk@quicinc.com> >>>>>>>> --- >>>>>>>> drivers/usb/typec/ucsi/ucsi.c | 1 + >>>>>>>> 1 file changed, 1 insertion(+) >>>>>>>> >>>>>>>> diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c >>>>>>>> index c6dfe3d..509c67c 100644 >>>>>>>> --- a/drivers/usb/typec/ucsi/ucsi.c >>>>>>>> +++ b/drivers/usb/typec/ucsi/ucsi.c >>>>>>>> @@ -884,6 +884,7 @@ static void ucsi_handle_connector_change(struct work_struct *work) >>>>>>>> if (ret < 0) { >>>>>>>> dev_err(ucsi->dev, "%s: GET_CONNECTOR_STATUS failed (%d)\n", >>>>>>>> __func__, ret); >>>>>>>> + clear_bit(EVENT_PENDING, &con->ucsi->flags); >>>>>>>> goto out_unlock; >>>>>>>> } >>>>>>> >>>>>>> I think it would be better to just move that label (out_unlock) above >>>>>>> the point where clear_bit() is already called instead of separately >>>>>>> calling it like that. That way the Connector Change Event will >>>>>>> also get acknowledged. >>>>>> Do we really need to ACK in this case since we didn't process the current >>>>>> connector change event >>>>> >>>>> You won't get the next event before the first one was ACK'd, right? >>>>> >>>> >>>> The spec says that we need to ACK if we received AND processed a CCI >>>> >>>> "4.5.4 Acknowledge Command Completion and/or Change Indication (R) >>>> This command is used to acknowledge to the PPM that the OPM received and >>>> processed a Command Completion and/or a Connector Change Indication." >>>> >>>> And here in this case, we have received, but not processed the event. >>>> So I'm not really sure what to do here in this case. If we don't send an >>>> ACK, then would the PPM think that OPM is not responding and reset it? >>>> OR would it resend the previous event again since we didn't ACK? >>> >>> Every PPM behaves differently. >>> >>> Did you actually see that happening - GET_CONNECTOR_STATUS failed? Can >>> you reproduce it? >>> >> >> Yea we actually hit the issue once where GET_CONNECTOR_STATUS failed and >> subsequent events didn't get queued since EVENT_PENDING wasn't cleared. Its >> not easily reproducible (<1%) though. >> >> [4948:kworker/0:3]UCSI: ucsi_qti_glink_write: timed out >> [4948:kworker/0:3]ucsi_glink soc:qcom,pmic_glink:qcom,ucsi: >> ucsi_handle_connector_change: GET_CONNECTOR_STATUS failed (-110) > > Okay. It would be really interesting to know why is it failing. > But let's just go with this for now. > > thanks, >
Agreed, I'm not really sure why its failing, because its in happening the lower layers. Anyways thanks for the comments and review!
Regards,
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