Hi! I have using Brain Boxes UC-260 4xserial port card for many years on Debian 6.0.10 Squeeze. Now I have build a new box with this card for Stretch and I recognize that old "tricks" are does not work. The old recipe was /etc/lilo.conf append="8250.nr_uarts=8" In result I have 8 nodes for serial devices, up to ttyS7 /etc/serial.conf /dev/ttyS4 uart 16750 port 0xd100 irq 20 baud_base 115200 spd_normal skip_test ^fourport /dev/ttyS5 uart 16750 port 0xd108 irq 20 baud_base 115200 spd_normal skip_test ^fourport /dev/ttyS6 uart 16750 port 0xd110 irq 20 baud_base 115200 spd_normal skip_test ^fourport /dev/ttyS7 uart 16750 port 0xd118 irq 20 baud_base 115200 spd_normal skip_test ^fourport Thats all. Every port are working well. With stretch it does not work at all. After reboot, from command line: $ setserial /dev/ttyS4 -a Invalid argument
Same command but as root: # setserial /dev/ttyS4 -a /dev/ttyS4, Line 4, UART: 16750, Port: 0xd100, IRQ: 20 Baud_base: 115200, close_delay: 50, divisor: 0 closing_wait: 3000 Flags: spd_normal skip_test Seem to be work? - not yet, using minicom it can not receive even himself (sort cut pins 2-3 w/o any handshake). Port address and irq was taken from lspci and proved by windows 10 running on the same box. I cleaned up /etc/serial.conf as this card does not exist at all. I tried to setup serial by hand: # setserial /dev/ttyS4 uart 16550A port 0xd100 irq 20 baud_base 115200 spd_normal skip_test Invalid argument The error seem less in kernel log. I have tried several settings - decide which argument is wrong. At last turn out that /dev/ttyS4, the device node is invalid, I can set it as /dev/ttyS1 (no such a "standard" port in my box), but card still wont work. I have tried several Debian live Strecth and Jessie distros with the same result. I have also tried SystemRescue CD with more up to date kernel but got the same result. I also lookup the manufacturer suggested "driver" - in real it is only some patches in grub and rc.local but it still does not work. In windows 10 it is work well. I was submitted a bug report to Debian about the setserial, but I'm not sure that it is setserial problem, I suspect kernel? I have no idea what to do more. Any suggestion would be highly appreciated. I'm not too good in kernel debugging. Sincerely tovis