Mity CPU Platforms » MitySOM-5CSX Altera Cyclone V

Hello,

Hi,

I am working on enabling Jumbo Frames and need to increase the MTU size on the eth0, eth1, and br0 interfaces. While I was able to successfully update the MTU size for eth1 and br0, I encountered an issue with eth0. When attempting to bring the eth0 link down to modify its MTU size, the link is automatically brought back up, preventing me from making the change. Could you please advise on how to address this issue?

Hello,

It might be that you need to take br0 down before taking eth0 down. The issue could be that br0 isn't allowing eth0 to go down.

Dan

Hi,

yeah i'm tried that firstly i am down the br0 and its goes to down then after i am tried to down eth0, its going down properly but it automatically brings up, it was not able to bring down eth0.
please find the below screenshot.

Hi,

I was able to recreate the issue on a board here. The ifplugd service, which is used to detect ethernet connectivity status, is bringing eth0 up as soon as you bring it down. You need to stop the ifplugd service before bringing eth0 down.

Here is the commands I ran:

root@mitysom-c5:~# /etc/init.d/ifplugd stop
Stopping Network Interface Plugging Daemon: eth0.
root@mitysom-c5:~# ip link set br0 down
root@mitysom-c5:~# ip link set eth0 down 

Hi,

MTU size issue was Resolved, and now I am facing with Crontab.
Actually I am running an application code on boot time and that way I am added the Executable lines on crontab. I am facing an issue with that after booting, my code has been executed properly, but in UART its transmits data properly but not receiving the data. when i am running my application code normally in terminal after booting the HPS, it was working fine, but the issues was coming when the application code was running through crontab.

If your program is reading from standard input, it will not be able to read anything when launched from cron. cron jobs have their standard input closed (or set to /dev/null, I don't remember exactly) and standard out will be shown in the console. I am guessing that the UART you are referring to is the console serial port?
You cannot run an interactive application from cron and using the console port as anything other than the console is really not a good idea..
If you are talking about a different UART that your application has opened and configured itself, then something else is going on.