Most recent kernel where this bug did not occur: Unknown Distribution: FC4 Problem Description: Using 2 serial adapters based on the pl2303 (HX, I beleive) chipset. First device works fine, second is detected but non-functional (no TX/RX from a modem). I've tried switching the order they are attached (both adapters do work). lsusb: Bus 004 Device 001: ID 0000:0000 Bus 003 Device 001: ID 0000:0000 Bus 002 Device 003: ID 067b:2303 Prolific Technology, Inc. PL2303 Serial Port Bus 002 Device 001: ID 0000:0000 Bus 001 Device 002: ID 067b:2303 Prolific Technology, Inc. PL2303 Serial Port Bus 001 Device 001: ID 0000:0000 dmesg: drivers/usb/serial/usb-serial.c: USB Serial Driver core drivers/usb/serial/usb-serial.c: USB Serial support registered for pl2303 pl2303 1-2:1.0: pl2303 converter detected usb 1-2: pl2303 converter now attached to ttyUSB0 pl2303 2-1:1.0: pl2303 converter detected usb 2-1: pl2303 converter now attached to ttyUSB1 usbcore: registered new driver pl2303 drivers/usb/serial/pl2303.c: Prolific PL2303 USB to serial adaptor driver Steps to reproduce: Attached two pl2303 devices, attempt to use second device.
Can you load the driver with "modprobe pl2303 debug=1" to see if we can get some good debugging messages when you try to access the second device? I tested this a long time ago, and it should work... Just attach the kernel log output for when you do this please.
Please reopen this bug if: - it is still present in kernel 2.6.17 and - you can provide the requested data.