[PATCH] genirq: move mask_cache into struct irq_chip_type

[Simon Guinot]

On Wed, Mar 06, 2013 at 04:19:30PM +0100, Thomas Gleixner wrote:
> On Wed, 6 Mar 2013, Simon Guinot wrote:
> 
> > On Tue, Mar 05, 2013 at 11:15:04AM +0100, Thomas Gleixner wrote:
> > > On Mon, 4 Mar 2013, Simon Guinot wrote:
> > > > On Mon, Mar 04, 2013 at 03:28:14PM +0100, Gerlando Falauto wrote:
> > > > 
> > > > AFAIK this issue is still here. I include the current Orion maintainers
> > > > in the Cc list.
> > > 
> > > Can you please resend the patch?
> > 
> > Hi Thomas,
> > 
> > Do you agree with the original patch concept: moving mask_cache from
> > struct irq_chip_generic into struct irq_chip_type ?
> 
> Not really. See below.
>  
> > This allows to handle the irq_chips which have separate mask registers
> > for the edge and level interrupts. At the time of this patch, this was
> > the only existing case.
> > 
> > Saeed objected that the patch was not correct because this was breaking
> > "hypothetic" devices with multiple irq_chip_type and a single mask
> > register.
> 
> Not so hypothetic. There _are_ irq controllers out there which use the
> same mask register for both level and edge type irqs.

Sure, but if the same mask register is used, then a single irq_chip_type
should be able to handle both level and edge interrupts ? I mean, if one
needs to register different irq_chip_type for edge and level interrupts,
it is most likely because the registers are not the same...

Simon

> 
> > The other option was to provide some dedicated irq_mask handlers for the
> > Orion irq chip.
> 
> I'd rather refactor the core code so it uses a pointer to the
> mask_cache. The default would be to let it point to gc->mask_cache and
> optionally let it point to ct->mask_cache. We'd need to store the flag
> in the gc struct so we can redirect the pointer to the ct->mask_cache
> in irq_setup_alt_chip().
> 
> Thanks,
> 
> 	tglx
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