Re: [PATCH] pinctrl: rockchip: don't disable clk when irq mask is already set

[Shawn Lin]

å 2016/9/27 6:35, Heiko Stuebner åé:
> Am Samstag, 24. September 2016, 18:24:11 CEST schrieb Shawn Lin:
> > On 2016/9/24 2:26, Jacob Chen wrote:
> > > From: Jacob Chen <jacob2.chen@xxxxxxxxxxxxxx>
> > >
> > > In some drivers, disable_irq() call don't be symmetric with enable_irq()
> > > , disable_irq() will be called before call free_irq().
> >
> > Which upstream drivers you refer to?
> >
> > Shouldn't it be the unbalanced call for these drivers?
> >
> > > But both disable_irq() and free_irq() will call
> > > rockchip_irq_gc_mask_set_bit,>
> > >  and clk_disable() will be called more times than clk_enable(), which will
> > >
> > > cause bugs.
> > >
> > > I think we can correct that by checking of mask.If mask is already set, do
> > > nothing.
> > Looks like a little hacky to me.
>
> that may be true, but on first glance I tend to agree with Jacob.
> Look for example at (a driver using disable_irq I picked at random) drivertc/
> rtcrs/-tps6586x.c .

yep, I took a quick look at the files you pointed to, and it seems
there should be the problems for what this patch to deal with. Probably
I didn't see this error since the drivers we was using happened to
handle it properly but maybe not for other drivers. I am okay if this
could solve problems for Jacob.

> In its probe function it does devm_request_irq directly followed by
> disable_irq on its alarm interrupt. The interrupt only gets enabled again if
> the rtc alarm gets enabled. So you can easily run into the disable + free case
> there as well. Similar probably in a lot of other drivers.
>
>
> Heiko
>
> > > Change-Id: If19912c7658253e15531c04db6c70fdbffd5960a
> >
> > remove this.
> >
> > > Signed-off-by: Jacob Chen <jacob2.chen@xxxxxxxxxxxxxx>
> > > ---
> > >
> > >  drivers/pinctrl/pinctrl-rockchip.c | 4 ++++
> > >  1 file changed, 4 insertions(+)
> > >
> > > diff --git a/drivers/pinctrl/pinctrl-rockchip.c
> > > b/drivers/pinctrl/pinctrl-rockchip.c index c6c04ac..9a8804a 100644
> > > --- a/drivers/pinctrl/pinctrl-rockchip.c
> > > +++ b/drivers/pinctrl/pinctrl-rockchip.c
> > > @@ -2334,8 +2334,12 @@ static void rockchip_irq_gc_mask_clr_bit(struct
> > > irq_data *d)>
> > >  void rockchip_irq_gc_mask_set_bit(struct irq_data *d)
> > >  {
> > >
> > >  	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
> > >
> > > +	struct irq_chip_type *ct = irq_data_get_chip_type(d);
> > >
> > >  	struct rockchip_pin_bank *bank = gc->private;
> > >
> > > +	if (*ct->mask_cache & d->mask)
> > > +		return;
> > > +
> > >
> > >  	irq_gc_mask_set_bit(d);
> > >  	clk_disable(bank->clk);
> > >
> > >  }
> > >
> > > --
> > > 2.7.4
> > >
> > >
> > > _______________________________________________
> > > Linux-rockchip mailing list
> > > Linux-rockchip@xxxxxxxxxxxxxxxxxxx
> > > http://lists.infradead.org/mailman/listinfo/linux-rockchip
>
>
>
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--
Best Regards
Shawn Lin