Re: Christmas list for the kernel

Jon Smirl
2005-11-23T15:13:01Z

On 11/23/05, Russell King <rmk+lkml@arm.linux.org.uk> wrote:
> > Plus I have 64 tty devices. Couldn't the tty devices be created
> > dynamically as they are consumed? Same for the loop and ram devices?
>
> You do realise that the dynamic device creation for those 64 console
> devices is done via the console device being _opened_ by userspace?
>
> Hence, if the device doesn't exist in userspace, it can't be created
> for userspace to open it to create the device via udev. Have you
> noticed a catch-22 with that statement?

Couldn't we create tty0-3 and then when one of those gets opened,
create tty4, and so on? Then there would always be two or three more
tty devices than there are open tty devices.

>
> Note that with tty devices, the tty layer has to be told the number
> of devices you want to support when you first register your driver.
> You're fixed to that maximum number from that point on, until you
> unregister *all* your ports and driver.
>
> --
> Russell King
> Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/
> maintainer of: 2.6 Serial core
>

--
Jon Smirl
jonsmirl@gmail.com