RE: [PATCHv2] OMAP: Enable Magic SysRq on serial console ttyOx

From: Anand Gadiyar
Date: Thu Jan 20 2011 - 07:19:51 EST


> > >>>> Magic SysRq key is not working for OMAP on new serial
> > >>>> console ttyOx because SUPPORT_SYSRQ is not defined
> > >>>> for omap-serial.
> > >>>>
> > >>>> This patch defines SUPPORT_SYSRQ in omap-serial and
> > >>>> enables handling of Magic SysRq character.
> > >>>>
> > >>>> Signed-off-by: Thomas Weber <weber@xxxxxxxxxxxxx>
> > >>>
> > >>> Looks fine to me.
> > >>>
> > >>> Acked-by: Govindraj.R <govindraj.raja@xxxxxx>
> > >> I tried to use SysRq key on minicom after applying this patch, it
looks
> > >> like it is not triggering sysrq event.
> > >>
> > >> Am I missing anything?
> > >>
> > >> -Manjunath
> > >> --
> > > Hello Manjunath,
> > >
> > > Do you have CONFIG_MAGIC_SYSRQ enabled?
> > > Magic SysRq key in Kernel Hacking
> > >
> > > I tested it on Devkit8000 (beagle board clone).
> > >
> >
> > re-setting lsr_break_flag to 0 in receive chars is causing issues
> > in getting sysrq key break sequence on omap-serial.c
> >
> > Manju,
> >
> > can you try this change on your environment.
> > With below change works for me on 3430SDP/4430SDP.
> > key sequence I checked.
> > [alt + b + t] => shows trace of tasks running.
> > [alt + b + b] => system reboot.
>
> With below patch, it works fine on TeraTerm. However, I am not able to
> perform the same on minicom.
>
> Tested-by: Manjunath G Kondaiah <manjugk@xxxxxx>
>
> -Manjunath
>

Not sure what you guys are trying out, but I am able to use sysrq
just fine in minicom (using only Thomas' original patch) - you need
to send a break sequence, and the way to do this in minicom is to
do Ctrl-A followed by F.

Works for me, without the "resetting lsr_break_flag to 0" part.

@Govind,

What are the issues you see in getting sysrq key break sequence
without your change? And how is your change fixing this?


- Anand
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