Hi Jeffrey,
I have a CH341 UART connected to this machine (Fedora 37 x86_64). Its stable, and has never caused me any real problems. However, my log looks slightly different. I get this:
Nov 29 13:43:34 haswell kernel: usb 1-4: new full-speed USB device number 12 using xhci_hcd Nov 29 13:43:34 haswell kernel: usb 1-4: New USB device found, idVendor=1a86, idProduct=7523, bcdDevice= 2.64 Nov 29 13:43:34 haswell kernel: usb 1-4: New USB device strings: Mfr=0, Product=2, SerialNumber=0 Nov 29 13:43:34 haswell kernel: usb 1-4: Product: USB Serial Nov 29 13:43:34 haswell kernel: ch341 1-4:1.0: ch341-uart converter detected Nov 29 13:43:34 haswell kernel: usb 1-4: ch341-uart converter now attached to ttyUSB0
The bcdDevice field is different. That sounds like a big difference in revision numbers. Maybe we have different devices from the CH341 family. Maybe there is some compatibility issue there. Maybe you just have a dirty USB connector, or some other bad connection problem.
Steve
On 29/11/2023 02:55, Jeffrey Ross via users wrote:
I'm trying to connect an Arduino to my system (Fedora 38 - 6.5.12-200.fc38.x86_64) that uses a ch341 serial uart.
I've been searching around and found issues on other distributions and the "brltty" application, since I don't need braille I removed the application but the problem remains. I have also found a different driver called "CH341SER" so I tried unloading the existing ch341 module and installing CH341SER (module shows up as ch34x) but other than tainting the kernel it made no different so I unloaded the module.
I have been unable find anything specific to Fedora or anything relatively new but it appears to be a common issue across multiple distributions.
Any pointers would be appreciated, see below for dmesg output.
Thanks, Jeff
[ 268.820420] usb 1-9.3.7: new full-speed USB device number 50 using xhci_hcd [ 268.897931] usb 1-9.3.7: New USB device found, idVendor=1a86, idProduct=7523, bcdDevice=81.34 [ 268.897947] usb 1-9.3.7: New USB device strings: Mfr=0, Product=2, SerialNumber=0 [ 268.897953] usb 1-9.3.7: Product: USB Serial [ 268.907342] ch341 1-9.3.7:1.0: ch341-uart converter detected [ 268.908444] usb 1-9.3.7: ch341-uart converter now attached to ttyUSB0 [ 272.084557] usb 1-9.3.7: USB disconnect, device number 50 [ 272.084964] ch341-uart ttyUSB0: ch341-uart converter now disconnected from ttyUSB0 [ 272.085012] ch341 1-9.3.7:1.0: device disconnected [ 274.196380] usb 1-9.3.7: new full-speed USB device number 51 using xhci_hcd [ 274.273474] usb 1-9.3.7: New USB device found, idVendor=1a86, idProduct=7523, bcdDevice=81.34 [ 274.273489] usb 1-9.3.7: New USB device strings: Mfr=0, Product=2, SerialNumber=0 [ 274.273495] usb 1-9.3.7: Product: USB Serial [ 274.282837] ch341 1-9.3.7:1.0: ch341-uart converter detected [ 274.283898] usb 1-9.3.7: ch341-uart converter now attached to ttyUSB0 [ 277.716513] usb 1-9.3.7: USB disconnect, device number 51 [ 277.716910] ch341-uart ttyUSB0: ch341-uart converter now disconnected from ttyUSB0 [ 277.716956] ch341 1-9.3.7:1.0: device disconnected