[PATCH 2/2] misc: atmel_pwm: set initcall level to subsys
Johan Hovold
jhovold at gmail.com
Wed Oct 30 07:07:05 EDT 2013
On Tue, Oct 29, 2013 at 04:22:49PM -0700, Greg KH wrote:
> On Tue, Oct 22, 2013 at 06:32:40PM +0200, Johan Hovold wrote:
> > Even with the atmel_pwm driver and the atmel-pwm-bl backlight driver
> > supporting deferred probing, we still want to make sure that any
> > pwm-device is available when the backlight devices are probed to avoid
> > any unnecessary delays before enabling the backlight.
> >
> > Signed-off-by: Johan Hovold <jhovold at gmail.com>
> > ---
> > drivers/misc/atmel_pwm.c | 12 +++++++++++-
> > 1 file changed, 11 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/misc/atmel_pwm.c b/drivers/misc/atmel_pwm.c
> > index a6dc56e..0d0f599 100644
> > --- a/drivers/misc/atmel_pwm.c
> > +++ b/drivers/misc/atmel_pwm.c
> > @@ -395,7 +395,17 @@ static struct platform_driver atmel_pwm_driver = {
> > */
> > };
> >
> > -module_platform_driver_probe(atmel_pwm_driver, pwm_probe);
> > +static int __init pwm_init(void)
> > +{
> > + return platform_driver_probe(&atmel_pwm_driver, pwm_probe);
> > +}
> > +subsys_initcall(pwm_init);
>
> I really hate this type of patch, as it's papering over the real
> problem. What happens when someone else moves their driver to this
> level? Then you are back to the original problem.
Yes, it's crude, but it's currently the only way to express a preferred
probe order.
> This is what deferred probing was supposed to fix. If it doesn't, then
> something else needs to be done, or fix the deferred probing mess...
Deferred probing (the first patch) fixes the dependency problem, but may
introduce delays. I can live with that.
> Sorry, I can't take this.
Fair enough.
Thanks,
Johan
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