On Tue, Apr 09, 2019 at 10:15:59AM +0100, Alexandru Elisei wrote:
> On 4/9/19 8:40 AM, Andrew Jones wrote:
> > On Mon, Apr 08, 2019 at 04:11:25PM +0100, Alexandru Elisei wrote:
> >> The prototype for the halt() function is incorrect, because halt() doesn't
> >> take any arguments. Fix it by using the prototype from smp.h.
> >>
> >> Signed-off-by: Alexandru Elisei <alexandru.elisei@xxxxxxx>
> >> ---
> >> lib/arm/io.c | 5 ++---
> >> 1 file changed, 2 insertions(+), 3 deletions(-)
> >>
> >> diff --git a/lib/arm/io.c b/lib/arm/io.c
> >> index 8226b765bdc5..6d3d7afed002 100644
> >> --- a/lib/arm/io.c
> >> +++ b/lib/arm/io.c
> >> @@ -15,11 +15,10 @@
> >> #include <asm/psci.h>
> >> #include <asm/spinlock.h>
> >> #include <asm/io.h>
> >> +#include <asm/smp.h>
> >>
> >> #include "io.h"
> >>
> >> -extern void halt(int code);
> >> -
> >> static struct spinlock uart_lock;
> >> /*
> >> * Use this guess for the uart base in order to make an attempt at
> >> @@ -93,6 +92,6 @@ void exit(int code)
> >> {
> >> chr_testdev_exit(code);
> >> psci_system_off();
> >> - halt(code);
> >> + halt();
> >> __builtin_unreachable();
> >> }
> >> --
> >> 2.17.0
> >>
> > I don't mind this change, because per the code it is the "correct"
> > thing to do. However, I was being a bit tricky here when I wrote it.
> > By changing the prototype to take 'code' as argument we guarantee
> > that 'code' will be in x0/r0 when we halt, giving us a last chance
> > to see it when inspecting the halted unit test state.
> >
> > Anyway, like I said, I'm fine with the cleanup, but the prototype
> > abuse does serve a purpose - maybe just not a good enough purpose
> > to justify the weirdness.
>
> Now it makes sense. I didn't think it was intentional, but now that you have
> mentioned it, the same pattern is used by powerpc.
No surprise there. I wrote that too, based on the arm code :)
>
> Perhaps a comment explaining that having different prototypes was on purpose
> would be the best solution?
Yes, either a comment explaining the weirdness or your patch to
remove it would be a good idea in order to avoid future head
scratching. I'll send a patch that adds comments to both arm and
powerpc.
Thanks,
drew
