Through ssh login on CentOS, we set /dev/ttyS0 to work in polling mode by
making its irq=0 using the following command

$ setserial /dev/ttyS0 uart 16550a irq 0

Now we are getting login prompt on serial console.

When we change /dev/ttyS0 back to interrupt mode with irq=4, we are not
getting login prompt over serial console.

We do not have a serial port connected to ttyS0 of BMC. So ttyS4 of BMC is
used as local-tty in obmc-console configuration.

Whether anything is required to be done in OpenBMC firmware to enable irq
mode for serial redirection.

On Wed, Nov 6, 2019 at 7:09 PM AKASH G J <akashgj91@gmail.com> wrote:

> Hi all,
>
> We are using BMC Aspeed AST-2500 in our motherboard with OpenBMC firmware.
> 'obmc-console' is used to get host messages over BMC. obmc-console.conf
> looks like
>
>
>
>
> *lpc-address = 0x3f8sirq = 4local-tty = ttyS4local-tty-baud = 115200*
>
> BIOS serial redirection is enabled over COM port 0 (0x3f8, sirq=4,
> baudrate=115200) for super-IO.
>
> We are getting BIOS debug messages, grub entries on BMC. But Linux booting
> is very slow, it is not printing systemd status messages(OK/FAILED) on
> serial console. Also is not giving login prompt on the serial console over
> BMC.
>
> Please someone help to resolve the problem.
>
>
> Thanks and Regards,
>
> Akash
>