[PATCH 1/2 v1] davinci: support disabling modem status interrupts on SOC UARTS
Manjunathappa, Prakash
prakash.pm at ti.com
Tue Jan 11 10:43:03 EST 2011
On Tue, Jan 11, 2011 at 18:12:25, Michael Williamson wrote:
> [...]
> This was pretty much what the original patch I had proposed did. There are
> actually two termios flags that cause MS interrupts to be enabled by the
> driver, CLOCAL (disabled) or CRTSCTS (enabled). I observed that some
> process after the kernel had completed booting (getty, I think)
> was calling set_termios with CLOCAL disabled (not CRTSCTS enabled). I could
> probably alter the getty args to work around it, but it's a bit of a hole to
> not have something in the kernel to preclude sending the OS to "interrupt
> hell".
>
> Is there another way to accomplish what you are suggesting that is different
> from the original patch?
>
> Thanks for the comments.
>
> -Mike
>
> Background: The original patch (not accepted) is here
> https://patchwork.kernel.org/patch/442671/
>
> This kicked a second email thread:
> http://marc.info/?l=linux-serial&m=129409970003827&w=4
>
> From that thread, it was suggested to add a port flag to the driver
> flags structure for disabling MS interrupts.
>
> Driver Tweak patch (not accepted):
> https://patchwork.kernel.org/patch/450771/
>
> From that thread, it was suggested to override the I/O methods and hide
> the problem back in the platform code (this patch).
>
> All three proposed patches work for me. I'd gladly submit a fourth if
> suggested -- this problem pretty much kills a couple of platform
> configurations we are working on...
>
> > Thanks,
> > Prakash
> >
Thanks for clarifying. Looks like this is what we can do as of now.
Thanks,
Prakash
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