LinuxQuestions.org
Visit Jeremy's Blog.
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Hardware
User Name
Password
Linux - Hardware This forum is for Hardware issues.
Having trouble installing a piece of hardware? Want to know if that peripheral is compatible with Linux?

Notices


Reply
  Search this Thread
Old 04-08-2021, 03:56 AM   #1
Michael65589
LQ Newbie
 
Registered: Oct 2019
Posts: 3

Rep: Reputation: Disabled
Cannot set serial speed over stty but screen works


I have a very strange issue with my serial com ports. The com ports are on an PCIexpress card.

[ 1.206744] 0000:05:00.0: ttyS4 at I/O 0x30c0 (irq = 18, base_baud = 115200) is a XR16850
[ 1.206832] 0000:05:00.0: ttyS5 at I/O 0x30c8 (irq = 18, base_baud = 115200) is a XR16850

Normally I use picocom to connect an embedded device that use its serial interface as debug console.

Everything was fine for months but suddenly I only receive weird characters.
After some investigations I found out that the baudrate of my port is 9600 instead of 115200. Picocom shows that it initialized the port with 115200 bps but when I check with stty the port it says only 9600 bps.
When I use C-v (show progam options) with picocom it shows
*** baud 115200 (9600)

So picocom and ssty are not able to change the baudrate. But when I use screen program everything works fine. WHY???

picocom /dev/ttyS5 -b 115200 -> doesn't work
screen /dev/ttyS5 115200 -> work

When I use picocom with a USB device it works too. Also I can change the baudrate of the USB device with stty.

Any suggestions? What can I do? Is there a way to reset the ttyS5 device? Or reinstall the device?
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off



Similar Threads
Thread Thread Starter Forum Replies Last Post
after upgrading Debian 9 to 10 (Buster): internet partially inaccessible over Wifi (but works over LAN) furryspider Debian 4 07-08-2020 03:02 PM
Multi serial card, setserial cannot set serial hua Linux - Hardware 1 06-11-2008 04:59 AM
How to use stty to set serial port speed Cara25 Linux - Newbie 1 06-18-2006 12:46 AM
XAWTV works, videodog works, motion works but how to code my own? rylan76 Linux - Hardware 0 01-06-2006 06:30 AM
using Stty to change serial port settings dkarnad Linux - General 1 12-21-2004 07:47 AM

LinuxQuestions.org > Forums > Linux Forums > Linux - Hardware

All times are GMT -5. The time now is 07:24 PM.

Main Menu
Advertisement
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Open Source Consulting | Domain Registration