Hi Marc,
On 7/25/20 11:27 AM, Marc Zyngier wrote:
On 2020-07-25 16:57, Suman Anna wrote:
Suman,
Hi Marc,
[...]
@@ -244,8 +295,14 @@ static int pruss_intc_probe(struct
platform_device *pdev)
return -ENOMEM;
for (i = 0; i < MAX_NUM_HOST_IRQS; i++) {
+ if (intc->invalid_intr & BIT(i))
+ continue;
+
irq = platform_get_irq_byname(pdev, irq_names[i]);
if (irq <= 0) {
+ if (intc->shared_intr & BIT(i))
+ continue;
I don't really understand why you are treating these "shared"
interrupts
differently from the invalid ones. In all cases, they shouldn't be
used.
The behavior is the same in how we handle it, but the difference is
that an "invalid" one is never even connected to the ARM interrupt
controller, while the "shared" one is a choice. So, unless this
interrupt is being used/handled by a different processor/entity, you
would not see this skipped from the dts node.
And I'm saying that all that matters is that you are discarding these
interrupts. Whether they are flagged invalid or shared, they are not
available to Linux. So the difference in handling is pointless and
only makes it harder to understand what you are doing.
The primary reason for using two properties and this logic was to
accurately describe the h/w and usage of these in the DT bindings to
distinguish the "never connected" vs the "optionally can be skipped"
interrupts rather than go by how these are handled in the driver. I
feel we will loose this description and make it confusing for SoC
product integration developers.
This logic makes zero difference to Linux, and I do not see what
you gain by having two code paths with separate list of unusable
interrupts.
OK, I understand your stance on this.
And why on Earth would a "Soc product integration
developer" have any business to mess with this driver code?
They should very much stay away from it and deal with their
precious value add.
It really depends on how they put together the system and exercise the
PRUs and the number of processors interacting with them. We have had
customers put together usecases where both the ARM core running Linux
and a remote processor like an M4 or R5 talk to the PRU at the same
time, or even inter PRUSS instances. They would have to adjust the DT in
their board dts files in general.
If you want two properties or even twenty, go for it, and have fun.
Just don't make this driver even more unreadable than it already is.
Merge all these interrupts in *one* list of unusable interrupts,
and be done with it.
Yes, we are merging this for the next version.
regards
Suman
