On Thu, Apr 3, 2014 at 8:00 AM, Jakub Jermar <[email protected]> wrote:
> On 2.4.2014 23:51, Jakub Jermar wrote:
>> In this approach, AFAIR, it would be primarily or exclusively the
>> interrupt controller driver that would use the pseudocode. All other
>> drivers would register for interrupts at the interrupt controller
>> driver (itself a DDF driver) and receive interrupt notifications from
>> it instead of from the kernel. So these other drivers would not
>> provide pseudocode, because it would not be needed.
>
> When thinking about it, maybe this second approach will be necessary
> because of the architecture of some of the more exotic platforms.
> Meaning, that each driver will be receiving interrupts from or at least
> via its parent in the device tree. And that all interrupt routing will
> be closely based on the device tree hierarchy.

I thought Jiri might chip in some more details before continuing the
discussion. So far might understanding of the new approach is:
PIC driver irqcode disables specific irq line on interrupt and
notifies uspace pic/platform driver. pic/platofrm driver cascades the
information to all devices that use that line, and let them figure out
the rest. The device that actually caused the interrupt will ask the
pic/platform driver to reanable the line once it is safe again.
Is this correct?
I want to avoid the situation when we talk about different things :)

Jan

>
> Take, for example, MIPS Malta. On Malta, the kernel does not have a
> chance to figure out the exact IRQ number unless it knows something
> about the system controller (i.e. little brother Malta platform driver
> in the kernel, yuck) and the buses that are attached to it. For the
> kernel, all IRQs look the same (just an external interrupt vector, the
> real ISA IRQ number needs to be read from a system board-specific
> register), so it is reasonable to have them delivered to the Malta
> platform driver, that is the only reasonable component that can actually
> figure out this number and send it to the corresponding subtree.
>
> Just typing as thoughts emerge.
>
> Jakub
>
>
>
> _______________________________________________
> HelenOS-devel mailing list
> [email protected]
> http://lists.modry.cz/listinfo/helenos-devel

_______________________________________________
HelenOS-devel mailing list
[email protected]
http://lists.modry.cz/listinfo/helenos-devel

Reply via email to