Hi Simon, tcp_nagle_disable() helped. Now there is long delay only when there are also incoming packets while transmitting. This happens only when lwip_netconn_do_writemore() ends with error. That means there is not enough memory. So I will also check on this.
Thanks a lot. Br Marek From: lwip-users <[email protected]> On Behalf Of Simon Wilton Sent: Tuesday, March 03, 2020 1:31 PM To: Mailing list for lwIP users <[email protected]> Subject: Re: [lwip-users] FreeRTOS + Lwip, transmit gets BLOCKED Hi Marek There is an automatic back-off mechanism designed to stop nodes flooding the network with small TCP messages called Nagle algorithm. Check if you are being blocked by that. You can turn it off - i think on a per connection basis. There is also a similar thread that I found when i was looking at a similar problem http://lwip.100.n7.nabble.com/lwIP-hangs-on-transfers-with-many-short-packets-td11044.html BR Simon ________________________________ From: lwip-users <[email protected]<mailto:[email protected]>> on behalf of mjanicek <[email protected]<mailto:[email protected]>> Sent: 03 March 2020 08:46 To: [email protected]<mailto:[email protected]> <[email protected]<mailto:[email protected]>> Subject: [lwip-users] FreeRTOS + Lwip, transmit gets BLOCKED Hello, I have STM32F407 running FreeRTOS + Lwip (netconn). I have several tasks. Only one Task1 is transmitting continously small packets (85 bytes) every 5 miliseconds on ethernet. Transmitting is randomly paused for a long time (cca 1-2 sec) then it is resumed. Task1 in function lwip_netconn_do_write() takes the semaphore by sys_arch_sem_wait(LWIP_API_MSG_SEM(msg), 0) and Task1 gets BLOCKED. It remains blocked for cca 1-2 seconds. When tcpip_thread in function lwip_netconn_do_writemore() gives semaphore by sys_sem_signal(op_completed_sem) then Task1 gets finally READY. Please do you have idea why this is happening for such a long time? Thanks Marek -- Sent from: http://lwip.100.n7.nabble.com/lwip-users-f3.html _______________________________________________ lwip-users mailing list [email protected]<mailto:[email protected]> https://lists.nongnu.org/mailman/listinfo/lwip-users
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