Hello Alan,
As you asked more detail about this issue. So I am sharing more details..
Problem Statement:
We are facing issue of hang when powering up RX65N-rsk2mb board and connected
router simultaneously.
Test setup:
RX65N-RSK2MB board is connected to router through Ethernet.
Flash NuttX8.2 code to RX65N-RSK2MB
Steps to Reproduce the issue:
1. Connect RX65N-RSK2MB board to Router though Ethernet Interface
2. Connect Serial to get NSH console
3. Connect power cable to router and power cable to RX65N-RSK2MB board
4. Give power simultaneously to RX65N-RSK2MB board and Router.
5. Check serial console
Result:
NSH console is not observed because of hangs
Debugging and Analysis:
1.It is hanging at nxsem_wait(sem) during auto ip configuration by dhcp where
waiting for offer repsonse corresponding to dhcp_request at lock
nxsem_wait(sem). This lock is not getting released. So it is hanging.
2.As per my understanding router may not be in UP state when discovery message
send from board.So router will not send any ip offer message. So the above lock
will keep waiting for IP offer from router which never will come then it will
keep waiting since this lock will wait as long as necessary to get the lock.
3. It is hanging at inet_udp_recvfrom()=>net_lockedwait=>net_timedwait(sem,
NULL)
In net_timedwait(sem, abstime) , abstime is passed as NULL so lock is not taken
for timeout case mentioned in below code. The lock which taken in this case is
nxsem_wait(sem) that will wait as long as necessary to get the lock . Which is
causing the problem.
int net_timedwait(sem_t *sem, FAR const struct timespec *abstime){
...................................
if (abstime != NULL) {
/* Wait until we get the lock or until the timeout expires */
ret = nxsem_timedwait(sem, abstime);
} else {
/* Wait as long as necessary to get the lock */
ret = nxsem_wait(sem);
}.....................................
}
Thanks & Regards,
Surya
________________________________
From: Alan Carvalho de Assis <[email protected]>
Sent: 29 April 2020 18:00
To: [email protected] <[email protected]>
Subject: Re: Hang issue when powering up board and target simultaneously
________________________________
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Hi Surya,
Could you please give us more details?
It is hard to help when we don't know exactly what is your scenario
and the way you are doing it.
What debugger tool are you using?
Are you using the mainline ethernet driver?
(Please read your message again, I know you are using RX65 chip, but
many people don't know it and you didn't say it).
Which are the steps to reproduce this issue?
Does this issue happen on other arch as well (i.e. STM32) ?
BR,
Alan
On 4/29/20, Surya prakash Verma <[email protected]> wrote:
> Hello Everyone,
>
> We are facing issue of hang when powering up board and target
> simultaneously.
>
> We have debugged and observed that it is hanging at nxsem_wait(sem) during
> auto ip configuration by dhcp where waiting for
> offer repsonse corresponding to dhcp_request at lock nxsem_wait(sem). This
> lock is not getting released. So it is hanging.
>
> As per my understanding router may not be in UP state when discovery message
> send from board. So router will not send any IP offer message.
> So the above lock will keep waiting as this lock will wait as long as
> necessary to get the lock.
>
> Please let us know, if someone face similar issue.
>
> Regards
> SURYA PRAKASH VERMA
> MOB: +91 9916589237
> TATA ELXSI
> Tower B, 9th Floor, Prestige Shantiniketan
> ITPB Road, Whitefield, Bangalore 560048 India
>
>
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