Ubuntu 20.04.1 LTS 64bit getting: Error setting RS-232 mode: Inappropriate ioctl for device

[oldunixguy]

I compiled the src with gcc -o linux-serial-test linux-serial-test.c
I have a null modem cable from ttyS0 to ttyS4. Both tty are real rs-232 serial ports.

In shell1 I ran:
linux-serial-test -s -e -p /dev/ttyS4 -t -c -l 250 -b 57600
In shell2 I ran:
linux-serial-test -s -e -p /dev/ttyS0 -r -c -b 57600

In both instances I get:
Error setting RS-232 mode: Inappropriate ioctl for device

and then both instances appear to operate normally.
The error output is paltry. Any suggestions on what to add to the output to narrow down for you what is wrong?

thanks
oldunixguy

[cbrake]

It appears we are trying to clear the RS485 settings on a system that does not support it:

https://github.com/cbrake/linux-serial-test/blob/master/linux-serial-test.c#L569

Can you try this branch and see if that works?

https://github.com/cbrake/linux-serial-test/tree/feature-fix-rs485-error

All, any concerns with above change?

[oldunixguy]

roger that. I've been writing C since 1981 so whatever you need I can do it.... while in there would you consider me "enhancing" the error outputs throughout, such as adding the src line number the error emits from? thanks rich

…

On Wed, Oct 28, 2020 at 11:34 AM Cliff Brake ***@***.***> wrote: It appears we are trying to clear the RS485 settings on a system that does not support it: https://github.com/cbrake/linux-serial-test/blob/master/linux-serial-test.c#L569 Can you try this branch and see if that works? https://github.com/cbrake/linux-serial-test/tree/feature-fix-rs485-error All, any concerns with above change? — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#33 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ADBQBD6P3HU73WHXLUBVFG3SNBI2FANCNFSM4TB4C2IA> .

-- Richard A. Painter, P.E. Retired

[cbrake]

sure, pull requests are welcome

[oldunixguy]

havnt done a pull request.... I obtained the software using the create a zip button. do you have a crib sheet on what I should do? thanks rich

…

On Wed, Oct 28, 2020 at 1:10 PM Cliff Brake ***@***.***> wrote: sure, pull requests are welcome — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#33 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ADBQBD4Z7GSK53EIRPVXP4LSNBUCDANCNFSM4TB4C2IA> .

-- Richard A. Painter, P.E. Retired

[oldunixguy]

I am reading https://guides.github.com/activities/hello-world/ and will give this a try... rich

…

On Wed, Oct 28, 2020 at 1:10 PM Cliff Brake ***@***.***> wrote: sure, pull requests are welcome — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#33 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ADBQBD4Z7GSK53EIRPVXP4LSNBUCDANCNFSM4TB4C2IA> .

-- Richard A. Painter, P.E. Retired

[oldunixguy]

Cliff, I got the version you posted. I'm still new to git and couldnt figure out how to create a branch on your branch.... I added my enhanced perror and fprintf(stderr...) to your version and then ran the test.... I get the same error at the same (relative ) location in the code. It still reports: setup_serial_port() 581: Error setting RS-232 mode: Inappropriate ioctl for device where 581 is the line number.... Please bear with me while I figure out how to use git... I'm an old SCCS guy! To that end I attached my file version.... I'm going to start adding some more debugging and see where this takes me. thanks rich

…

On Wed, Oct 28, 2020 at 11:34 AM Cliff Brake ***@***.***> wrote: It appears we are trying to clear the RS485 settings on a system that does not support it: https://github.com/cbrake/linux-serial-test/blob/master/linux-serial-test.c#L569 Can you try this branch and see if that works? https://github.com/cbrake/linux-serial-test/tree/feature-fix-rs485-error All, any concerns with above change? — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#33 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ADBQBD6P3HU73WHXLUBVFG3SNBI2FANCNFSM4TB4C2IA> .

-- Richard A. Painter, P.E. Retired

[oldunixguy]

Cliff, here is the output of the first ioctl to get the rs485 params.... i modified the code to: ret = ioctl(_fd, TIOCGRS485, &rs485); ERROR("ioctl ret = %d, errno %d\n", ret, errno); setup_serial_port() 561: ioctl ret = 0, errno 0 rs485 ioctl output: 0x00000000 flags 0x00000000 delay_rts_before_send 0x00000000 delay_rts_after_send 0x00000000 padding[0] 0x00000000 padding[1] 0x00000000 padding[2] 0x00000000 padding[3] 0x00000000 padding[4] This suggests that ubuntu 20 returns success to the TIOCGRS485 BUT the contents of the params are all 0 Hummm. rich

…

On Wed, Oct 28, 2020 at 1:10 PM Cliff Brake ***@***.***> wrote: sure, pull requests are welcome — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#33 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ADBQBD4Z7GSK53EIRPVXP4LSNBUCDANCNFSM4TB4C2IA> .

-- Richard A. Painter, P.E. Retired

[cbrake]

Looks like you are making good progress. The IOCTL implementation is likely a function fo the Linux kernel serial driver, which can vary from system to system.

I went ahead and merged my changes to master: #34

Figuring out Git would be good -- if you need any help with Git, feel free to contact me directly via email. Figuring out the command line git client is the best approach (vs making edits in the GitHub web UI).