Re: UPD send delay

2020-11-09 Thread Gregory Nutt
There are two threads involved: 1. The user thread that calls the UDP sendto() interface: * Lock the network. * Call netdev_txnotify_dev() to inform the driver that TX data is available.  The driver should schedule the TX poll on LP work queue. * If CONFIG_NET_UDP_WRITE_BUFFERS is en

Re: UPD send delay

2020-11-09 Thread Gregory Nutt
I've already tested network throughput with 'udpblaster' tool and was happily wondering by NuttX capability to flood full Ethernet bandwidth in both directions simultaneously. That was one of the reasons why we've chosen NuttX for our project. "If it's so strong in flooding, it should have low l

Re: UPD send delay

2020-11-09 Thread Andrey Shetov
Thanks Gregory, for that wiki page. I've already tested network throughput with 'udpblaster' tool and was happily wondering by NuttX capability to flood full Ethernet bandwidth in both directions simultaneously. That was one of the reasons why we've chosen NuttX for our project. "If it's so strong

Re: UPD send delay

2020-11-09 Thread Gregory Nutt
Probably worth taking a look at https://cwiki.apache.org/confluence/display/NUTTX/TCP+Network+Performance That deals specifically with TCP but discussion related to the Ethernet driver also applies.  The NuttX (TCP) is capable of performing at network speeds; the performance bottleneck is alwa

Re: UPD send delay

2020-11-09 Thread Andrey Shetov
Here is my current config file. Thanks for advice about the work queue priority, I found and set the CONFIG_STM32H7_ETHMAC_HPWORK option. But mystically this make the latency worse - average ping-pong time increased from ~375 to ~400 usec.. On Mon, Nov 9, 2020 at 8:04 PM Maciej Wójcik wrote: >

Re: UPD send delay

2020-11-09 Thread Maciej Wójcik
In case of board I was working with, the network traffic was handled by low priority work queue. It is probably the same with your network driver. Such work queue has configuration. Maybe you need to change some parameters of it. It might help if you send here your configuration file, or part of

Re: UPD send delay

2020-11-09 Thread Andrey Shetov
Hi, Jukka. I'm working with the thread author on a low latency audio processor based on the STM32H7 chip and can provide some technical details about the issue. We've used Ethernet config from your repo bitbucket.org/jlaitin/nuttx/ and integrated it to master branch of Nuttx OS. After that, we've

Using multiple SPI devices on samd2l1

2020-11-09 Thread Bernd Walter
I am supposed to call an spoi bus init function to get the spi device I then use to register my device to. This is the code in sam34: / * Public Functions *