* [PATCH] platform/x86: sony-laptop: Mark expected switch fall-through
@ 2018-07-05 20:47 Gustavo A. R. Silva
2018-07-06 23:24 ` Darren Hart
0 siblings, 1 reply; 5+ messages in thread
From: Gustavo A. R. Silva @ 2018-07-05 20:47 UTC (permalink / raw)
To: Mattia Dongili, Darren Hart, Andy Shevchenko
Cc: platform-driver-x86, linux-kernel, Gustavo A. R. Silva
In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
drivers/platform/x86/sony-laptop.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/platform/x86/sony-laptop.c b/drivers/platform/x86/sony-laptop.c
index b205b03..e614cb7 100644
--- a/drivers/platform/x86/sony-laptop.c
+++ b/drivers/platform/x86/sony-laptop.c
@@ -4427,6 +4427,7 @@ sony_pic_read_possible_resource(struct acpi_resource *resource, void *context)
default:
dprintk("Resource %d isn't an IRQ nor an IO port\n",
resource->type);
+ /* fall through */
case ACPI_RESOURCE_TYPE_END_TAG:
return AE_OK;
--
2.7.4
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH] platform/x86: sony-laptop: Mark expected switch fall-through
2018-07-05 20:47 [PATCH] platform/x86: sony-laptop: Mark expected switch fall-through Gustavo A. R. Silva
@ 2018-07-06 23:24 ` Darren Hart
2018-07-07 16:19 ` Andy Shevchenko
2018-07-07 18:56 ` Mattia Dongili
0 siblings, 2 replies; 5+ messages in thread
From: Darren Hart @ 2018-07-06 23:24 UTC (permalink / raw)
To: Gustavo A. R. Silva
Cc: Mattia Dongili, Andy Shevchenko, platform-driver-x86, linux-kernel
On Thu, Jul 05, 2018 at 03:47:03PM -0500, Gustavo A. R. Silva wrote:
> In preparation to enabling -Wimplicit-fallthrough, mark switch cases
> where we are expecting to fall through.
>
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
> ---
> drivers/platform/x86/sony-laptop.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/platform/x86/sony-laptop.c b/drivers/platform/x86/sony-laptop.c
> index b205b03..e614cb7 100644
> --- a/drivers/platform/x86/sony-laptop.c
> +++ b/drivers/platform/x86/sony-laptop.c
> @@ -4427,6 +4427,7 @@ sony_pic_read_possible_resource(struct acpi_resource *resource, void *context)
> default:
> dprintk("Resource %d isn't an IRQ nor an IO port\n",
> resource->type);
> + /* fall through */
Here too, I wonder if this is intentional. Either way, from what I can see, the
final line in the function:
return AE_CTRL_TERMINATE;
Is unreachable as there are no "break" statements in the switch, and the default
falls through to return AE_OK. Something doesn't seem right here.
--
Darren Hart
VMware Open Source Technology Center
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] platform/x86: sony-laptop: Mark expected switch fall-through
2018-07-06 23:24 ` Darren Hart
@ 2018-07-07 16:19 ` Andy Shevchenko
2018-07-07 18:56 ` Mattia Dongili
1 sibling, 0 replies; 5+ messages in thread
From: Andy Shevchenko @ 2018-07-07 16:19 UTC (permalink / raw)
To: Darren Hart
Cc: Gustavo A. R. Silva, Mattia Dongili, Andy Shevchenko,
Platform Driver, Linux Kernel Mailing List
On Sat, Jul 7, 2018 at 2:24 AM, Darren Hart <dvhart@infradead.org> wrote:
> return AE_CTRL_TERMINATE;
>
> Is unreachable as there are no "break" statements in the switch, and the default
> falls through to return AE_OK. Something doesn't seem right here.
Darren, I didn't look at the code in question, though just to clarify
such error codes.
If the function used in acpi_walk_namespace() or alike, AE_OK means
"To continue", while AE_CTRL_TERMINATE to "stop, whatever we looked
for is found right now".
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] platform/x86: sony-laptop: Mark expected switch fall-through
2018-07-06 23:24 ` Darren Hart
2018-07-07 16:19 ` Andy Shevchenko
@ 2018-07-07 18:56 ` Mattia Dongili
2018-09-11 22:51 ` Darren Hart
1 sibling, 1 reply; 5+ messages in thread
From: Mattia Dongili @ 2018-07-07 18:56 UTC (permalink / raw)
To: Darren Hart
Cc: Gustavo A. R. Silva, Andy Shevchenko, platform-driver-x86, linux-kernel
On Fri, Jul 06, 2018 at 04:24:27PM -0700, Darren Hart wrote:
> On Thu, Jul 05, 2018 at 03:47:03PM -0500, Gustavo A. R. Silva wrote:
> > In preparation to enabling -Wimplicit-fallthrough, mark switch cases
> > where we are expecting to fall through.
> >
> > Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
> > ---
> > drivers/platform/x86/sony-laptop.c | 1 +
> > 1 file changed, 1 insertion(+)
> >
> > diff --git a/drivers/platform/x86/sony-laptop.c b/drivers/platform/x86/sony-laptop.c
> > index b205b03..e614cb7 100644
> > --- a/drivers/platform/x86/sony-laptop.c
> > +++ b/drivers/platform/x86/sony-laptop.c
> > @@ -4427,6 +4427,7 @@ sony_pic_read_possible_resource(struct acpi_resource *resource, void *context)
> > default:
> > dprintk("Resource %d isn't an IRQ nor an IO port\n",
> > resource->type);
> > + /* fall through */
>
> Here too, I wonder if this is intentional. Either way, from what I can see, the
> final line in the function:
>
> return AE_CTRL_TERMINATE;
>
> Is unreachable as there are no "break" statements in the switch, and the default
> falls through to return AE_OK. Something doesn't seem right here.
I think so too. Looks to me that the default case was meant to return
AE_CTRL_TERMINATE (i.e. swapping it to be last would do).
Having written that code aeons ago, I'm not sure if there is a good
reason to be like that, though it still looks like a bug (that
existed ever since...).
Want to fix it as part of this patch series? Or I can send a patch
myself, let me know.
--
mattia
:wq!
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] platform/x86: sony-laptop: Mark expected switch fall-through
2018-07-07 18:56 ` Mattia Dongili
@ 2018-09-11 22:51 ` Darren Hart
0 siblings, 0 replies; 5+ messages in thread
From: Darren Hart @ 2018-09-11 22:51 UTC (permalink / raw)
To: Mattia Dongili
Cc: Gustavo A. R. Silva, Andy Shevchenko, platform-driver-x86, linux-kernel
On Sun, Jul 08, 2018 at 03:56:17AM +0900, Mattia Dongili wrote:
> On Fri, Jul 06, 2018 at 04:24:27PM -0700, Darren Hart wrote:
> > On Thu, Jul 05, 2018 at 03:47:03PM -0500, Gustavo A. R. Silva wrote:
> > > In preparation to enabling -Wimplicit-fallthrough, mark switch cases
> > > where we are expecting to fall through.
> > >
> > > Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
> > > ---
> > > drivers/platform/x86/sony-laptop.c | 1 +
> > > 1 file changed, 1 insertion(+)
> > >
> > > diff --git a/drivers/platform/x86/sony-laptop.c b/drivers/platform/x86/sony-laptop.c
> > > index b205b03..e614cb7 100644
> > > --- a/drivers/platform/x86/sony-laptop.c
> > > +++ b/drivers/platform/x86/sony-laptop.c
> > > @@ -4427,6 +4427,7 @@ sony_pic_read_possible_resource(struct acpi_resource *resource, void *context)
> > > default:
> > > dprintk("Resource %d isn't an IRQ nor an IO port\n",
> > > resource->type);
> > > + /* fall through */
> >
> > Here too, I wonder if this is intentional. Either way, from what I can see, the
> > final line in the function:
> >
> > return AE_CTRL_TERMINATE;
> >
> > Is unreachable as there are no "break" statements in the switch, and the default
> > falls through to return AE_OK. Something doesn't seem right here.
>
> I think so too. Looks to me that the default case was meant to return
> AE_CTRL_TERMINATE (i.e. swapping it to be last would do).
>
> Having written that code aeons ago, I'm not sure if there is a good
> reason to be like that, though it still looks like a bug (that
> existed ever since...).
>
> Want to fix it as part of this patch series? Or I can send a patch
> myself, let me know.
Mattia,
I'd prefer to decouple the fix from the implicit fall through discussion. Please
send a separate fix.
--
Darren Hart
VMware Open Source Technology Center
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2018-09-11 22:51 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-07-05 20:47 [PATCH] platform/x86: sony-laptop: Mark expected switch fall-through Gustavo A. R. Silva
2018-07-06 23:24 ` Darren Hart
2018-07-07 16:19 ` Andy Shevchenko
2018-07-07 18:56 ` Mattia Dongili
2018-09-11 22:51 ` Darren Hart
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