On 13/07/2025 16:19, Danilo Krummrich wrote:
> On Sun Jul 13, 2025 at 4:09 PM CEST, Daniel Almeida wrote:
>> On a second look, I wonder how useful this will be.
>>
>> fn handle(&self, dev: &Device<Bound>) -> IrqReturn
>>
>> Sorry for borrowing this terminology, but here we offer Device<Bound>, while I
>> suspect that most drivers will be looking for the most derived Device type
>> instead. So for drm drivers this will be drm::Device, for example, not the base
>> dev::Device type. I assume that this pattern will hold for other subsystems as
>> well.
>>
>> Which brings me to my second point: drivers can store an ARef<drm::Device> on
>> the handler itself, and I assume that the same will be possible in other
>> subsystems.
>
> Well, the whole point is that you can use a &Device<Bound> to directly access
> device resources without any overhead, i.e.
>
> fn handle(&self, dev: &Device<Bound>) -> IrqReturn {
> let io = self.iomem.access(dev);
>
> io.write32(...);
As this is exactly the example I was discussing privately with Daniel
(many thanks!), independent on the device discussion here, just for my
understanding:
Is it ok to do a 'self.iomem.access(dev)' at each interrupt? Wouldn't it
be cheaper/faster to pass 'io' instead of 'iomem' to the interrupt handler?
fn handle(...) -> IrqReturn {
self.io.write32(...);
?
Thanks
Dirk
