Re: [PATCH v24 09/11] acpi/arm64: Add memory-mapped timer support in GTDT driver

[Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>]

On Wed, Apr 19, 2017 at 04:45:54PM +0100, Mark Rutland wrote:
> On Wed, Apr 19, 2017 at 04:07:25PM +0100, Mark Rutland wrote:
> > On Tue, Apr 18, 2017 at 06:21:07PM +0100, Lorenzo Pieralisi wrote:
> > > On Sat, Apr 15, 2017 at 02:40:12AM +0800, fu.wei@linaro.org wrote:
>  
> > > If yes, why can't it simply be written like this ?
> > > 
> > > for (; i >= 0; i--, gtdt_frame--) {
> > > 	frame = &timer_mem->frame[gtdt_frame->frame_number];
> > > 
> > > 	/* not sure this check is actually needed */
> > > 	if (gtdt_frame->common_flags & ACPI_GTDT_GT_IS_SECURE_TIMER)
> > > 		continue;
> > > 
> > > 	if (frame->phys_irq > 0)
> > > 		acpi_unregister_gsi(gtdt_frame->timer_interrupt);
> > > 	if (frame->virt_irq > 0)
> > > 		acpi_unregister_gsi(gtdt_frame->virtual_timer_interrupt);
> > > }
> > 
> > A reverse loop of this form will work.
> > 
> > That requires some restructuring, and care to avoid going out of bounds
> > instantaneously with the gtdt_frame--, so as to not invoke nasal demons.
> > 
> > I've attacked this locally, and will send this out after testing. I'll
> > drop the new ACPI API patch.
> 
> FWIW, I've set this up so the cleanup path is:
> 
> do {
>         if (gtdt_frame->common_flags & ACPI_GTDT_GT_IS_SECURE_TIMER ||
>             gtdt_frame->frame_number >= ARCH_TIMER_MEM_MAX_FRAMES)
>                 continue;
> 
>         frame = &timer_mem->frame[gtdt_frame->frame_number];
> 
>         if (frame->phys_irq > 0)
>                 acpi_unregister_gsi(gtdt_frame->timer_interrupt);
>         frame->phys_irq = 0;
> 
>         if (frame->virt_irq > 0)
>                 acpi_unregister_gsi(gtdt_frame->virtual_timer_interrupt);
>         frame->virt_irq = 0;
> } while (i-- >= 0 && gtdt_frame--);
> 
> ... the zeroing is to account for duplicate frames, which I now check for in
> the probe path (as we do for DT).
> 
> Can I take it per your comment on the prior version that with this change I can
> take your ack?

Yes, thanks for fixing it up, please add my:

Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

> I also assume that you're happy for all of the drivers/acpi/arm64/ patches in the
> series to go via the clocksource tree?

Yes that's how I expect them to go upstream, that's the simplest way.

Thanks !
Lorenzo