[parisc-linux] serial baud_base, high baud rates and divisors
Thu, 07 Feb 2002 09:31:07 -0700
Enrik Berkhan wrote:
> Investigating on
> that I've found some oddities concerning setserial, baud_base and
> the divisor calculation in the serial driver ...
> Memory mapped parisc ports all have port == 0, so this has to fail.
> Temporary workaround: `setserial /dev/ttyS1 port 0x10000 ...' once
> will prevent the above loop from finding conflicts.
> So, the following things have to be fixed:
> - get/set_serial_info have to be enhanced for memory mapped ports
> - setserial should be enhanced accordingly
If other non-intel architectures don't have a solution for this.
My first thought was to assign fake port addresses.
Do PCI serial cards also use MMIO?
> - divisor calculation should be changed at least to round to nearest,
> not round towards zero, or LASI ports might still suffer from the first
> problem _if_ they really have baud_base 454545
> - baud_base should be initialized correctly for other gsc based ports.
We'd have to dig a bit for documentation on this.
Please poke me offline if that doesn't happen in the next week or so.
> If someone can confirm my analysis and tell me the direction of how to
> fix these things I would be willing to work on it (shouldn't be hard,
> maybe boring ;-).
cool - thanks,