[...]

quoted

quoted

+
+                       clear_bit(c, &sources);
+               }
+
+               if (!sources)
+                       clear_bit(i, pending);

What does this signify and how does it happen? An SGI without a source
sounds pretty weird...

See the clear_bit() just above. Once all the sources for this SGI are
cleared, we can make the interrupt not pending anymore.

every time I read the code, I get completely bogged up on trying to
understand this case and I tell myself we should put a comment here,
then I understand why it happens and I think, oh it's obvious, no
comment needed, but now I (almost) forgot again. Could we add a
comment?

-Christoffer