Hello!
On 11.12.2021 2:45, Damien Le Moal wrote:
[...]
platform_get_irq() will print a message when it fails.
No need to repeat this.
While at it, drop redundant check for 0 as platform_get_irq() spills
out a big WARN() in such case.
The reason you should be able to remove the "if (!irq)" test is that
platform_get_irq() never returns 0. At least, that is what the function kdoc
says. But looking at platform_get_irq_optional(), which is called by
platform_get_irq(), the out label is:
WARN(ret == 0, "0 is an invalid IRQ number\n");
return ret;
So 0 will be returned as-is. That is rather weird. That should be fixed to
return -ENXIO:
if (WARN(ret == 0, "0 is an invalid IRQ number\n"))
return -ENXIO;
return ret;
My unmerged patch (https://marc.info/?l=linux-kernel&m=163623041902285) does this
but returns -EINVAL instead.
Thinking more about this, shouldn't this change go into platform_get_irq()
instead of platform_get_irq_optional() ?
Why? platform_get_irq() currently just calls platform_get_irq_optional()...
The way I see it, I think that the intended behavior for
platform_get_irq_optional() is:
1) If have IRQ, return it, always > 0
2) If no IRQ, return 0
That does include the IRQ0 case, right?
3) If error, return < 0
no ?
I completely agree, I (after thinking a bit) have no issues with that...
And for platform_get_irq(), case (2) becomes an error.
Is this the intended semantic ?
I don't see how it's different from the current behavior. But we can do
that as well, I just don't see whether it's really better...
I am really not sure here as the functions kdoc description and the code do not
match. Which one is correct ?
It seems both are wrong. :-)
[...]
MBR, Sergey
