Re: [PATCH 1/3] irqchip: atmel-aic5: fix bug with mask/unmask

From: Ludovic Desroches
Date: Tue Sep 22 2015 - 10:11:42 EST


On Tue, Sep 22, 2015 at 03:50:30PM +0200, Thomas Gleixner wrote:
> On Tue, 22 Sep 2015, Boris Brezillon wrote:
> > On Tue, 22 Sep 2015 12:27:08 +0200 (CEST)
> > Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:
> > > Why is this locking dgc->gc[0] and fiddling with some other generic
> > > chip?
> >
> > Actually, we always access the same set of registers for all irqs of the
> > domain, and thus need to take the same lock (I chose the one contained
> > in the first generic irqchip, but I guess it could work with the others
> > too, as long as we always take the same one) before accessing them
> > because the configuration is done in two steps:
> >
> > 1/ specify the irq line you want to configure
> > 2/ set the new configuration
> >
> > Regarding register accesses, all generic chips are configured to
> > point to the same registers, so accessing them from the 'base' generic
> > chip or from the generic chip attached to the irq_data struct is the
> > same, though I agree that using bgc would add some consistency to the
> > implementation.
>
> Fair enough. It just deserves a comment for the casual reader.
>

Thanks for the addition of the comment.

Ludovic
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