Messages in this thread | | | Date | Tue, 20 Jan 2015 14:08:53 +0100 (CET) | From | Thomas Gleixner <> | Subject | Re: [PATCH v2 1/5] irqchip: add dumb demultiplexer implementation |
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On Thu, 15 Jan 2015, Rob Herring wrote: > On Thu, Jan 15, 2015 at 3:11 AM, Thomas Gleixner <tglx@linutronix.de> wrote: > > On Wed, 14 Jan 2015, Rob Herring wrote: > > > We do not change shared interrupts in any way. We provide an > > alternative mechanism for braindead hardware. And if the at91 folks > > are fine with the DT change, then it's their decision. Nothing forces > > this on everyone. > > We are changing how shared interrupts are described in DT. We don't > need 2 ways to describe them. We could say this is only for AT91 and > continue to describe shared interrupts as has been done forever. Then > the next platform that hits this problem will have to go thru the same > ABI breakage. Or we change DT practices to describe all shared > interrupts with a demux node. Given the way DTs are incrementally > created, it is not something we can check with review or tools, so we > will still have the same ABI breakage problem.
This is not describing the proper shared interrupts. This is a special case for a special case of braindamaged hardware. Whats wrong with doing that? We dont have to change that for all shared interrupts because 99% of them have a proper hardware implementation and are not affected by this.
What's wrong with serving the AT91 with a proper solution, which does NOT inflict horrible hacks into the core code and does NOT weaken sanity checks and does NOT require irq chip specific knowledge in device drivers?
> >> There are probably ways to do this demux irqchip without a DT change.
So far you have not provided any useful hint how to do so.
> > What's the problem with a DT change for a single platform, if the > > maintainers are willing to take it and deal with the fallout? > > What's the solution for a platform that an ABI break is not okay and > can't deal with the fallout?
There is no other platform affected. This is a break for a specific set of devices and the 'fallout' is confined, well known and accepted.
So what's your problem, really?
Thanks,
tglx
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