Re: [PATCH ] printk: add module parameter console_suspend tocontrol console_suspend_enabled

From: Yanmin Zhang
Date: Tue Aug 09 2011 - 20:58:45 EST


On Tue, 2011-08-09 at 17:59 +0800, Dave Young wrote:
> Hi,
>
> On Tue, Aug 9, 2011 at 4:55 PM, Yanmin Zhang
> <yanmin_zhang@xxxxxxxxxxxxxxx> wrote:
> > On Tue, 2011-08-09 at 16:01 +0800, Dave Young wrote:
> >> On Tue, Aug 9, 2011 at 11:09 AM, Yanmin Zhang
> >> <yanmin_zhang@xxxxxxxxxxxxxxx> wrote:
> >> > We are enabling some power features on medfield. To test suspend-2-RAM
> >> > conveniently, we need turn on/off console_suspend_enabled frequently.
> >> >
> >> > Below patch adds a module parameter, so users could change it by:
> >> > /sys/module/printk/parameters/console_suspend_enabled
> >>
> >> What about change name to no_console_suspend? Or it will be weird if
> >> boot kernel with both no_console_suspend and
> >> printk.console_suspend_enabled set.
> > Thanks for the comments. How about changing the name to console_suspend?
> > If changing it to no_console_suspend, we can't map the input to console_suspend_enabled
> > directly.
>
> How about use module_param_cb instead of module_param_named?
Thanks for the pointer. Indeed, we could use module_param_cb to support the
input/output parsing. Is it too complicated to use it here? It's better
to keep simple. The new name console_suspend is clearer than old name.

>
> >
> > Below is the new patch.
> >
> > ---
> >
> > We are enabling some power features on medfield. To test suspend-2-RAM
> > conveniently, we need turn on/off console_suspend_enabled frequently.
> >
> > Below patch adds a module parameter, so users could change it by:
> > /sys/module/printk/parameters/console_suspend
> >
> > Signed-off-by: Yanmin Zhang <yanmin_zhang@xxxxxxxxxxxxxxx>
> >
> > ---
> > kernel/printk.c | 2 ++
> > 1 files changed, 2 insertions(+), 0 deletions(-)
> >
> > diff --git a/kernel/printk.c b/kernel/printk.c
> > index 37dff34..1decef6 100644
> > --- a/kernel/printk.c
> > +++ b/kernel/printk.c
> > @@ -1106,6 +1106,8 @@ static int __init console_suspend_disable(char *str)
> > return 1;
> > }
> > __setup("no_console_suspend", console_suspend_disable);
> > +module_param_named(console_suspend, console_suspend_enabled,
> > + bool, S_IRUGO | S_IWUSR);
> >
> > /**
> > * suspend_console - suspend the console subsystem
> > --


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/