Hi Stefan, > Hi Albert, > > On 22.06.2013 11:58, Albert ARIBAUD wrote: > > From time to time there is discussion about the need for proper > > interrupt support in U-Boot. > > > > Right now, the only thing left in the source code which remotely > > looks like interrupt support is a few code sections compiled > > conditionally under CONFIG_USE_IRQ, and it does not constitute a > > good approach to interrupt support, if only for the following > > reasons: > > > > - CONFIG_USE_IRQ is very general and imprecise as far as overall > > meaning goes. It does not say "allow drivers to use IRQs", or > > "IRQs are provided by supporting this specific interrupt > > controller", or "this driver requires IRQs to work". It does not > > help us either that the option was never documented... > > > > - CONFIG_USE_IRQ is, OTOH, very specific as far as interrupt types > > go. IRQ is an acronym known in ARM for a specific type of > > interrupt, but ARM also knows FIQ. IRQ may have a different meaning > > for another architecture, and each platform has its own > > classification and attributes for interrupts. > > > > - no API is defined for registering interrupt controller or > > interrupt client drivers. > > > > But the worst part is, CONFIG_USE_IRQ is never *ever* defined. :) > > > > So I am tempted to start this RFC with a first question: do we > > *need* interrupts in the first place, and if we do, do we need an > > organized interrupts subsystem or do we keep an ad hoc approach? > > I know that interrupts are currently used on PowerPC for the PPC4xx > ethernet driver (emac). This could be reworked to of cause, but I just > wanted to point this out. > > I have no idea if interrupts are used on any ARM platform though.
For me it looks, like a fundamental decision to support interrupts on ARM. Do we need them - it's an open question. Does anyone have good use case for it? On the other hand I remember that Marek was struggling to introduce new driver model. It was also a fundamental change and as fair as I know we don't have it yet finished. Anyway it is a good discussion topic :-) > > Thanks, > Stefan > > _______________________________________________ > U-Boot mailing list > U-Boot@lists.denx.de > http://lists.denx.de/mailman/listinfo/u-boot -- Best regards, Lukasz Majewski Samsung R&D Institute Poland (SRPOL) | Linux Platform Group _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot