linux-next: build warning after merge of the amdgpu tree

linux-next: build warning after merge of the amdgpu tree

[Stephen Rothwell]

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Hi all,

After merging the amdgpu tree, today's linux-next build (powerpc
allyesconfig) produced this warning:

In file included from include/linux/compiler_types.h:59,
                 from <command-line>:
drivers/gpu/drm/amd/amdgpu/../powerplay/hwmgr/smu7_hwmgr.c: In function 'smu7_request_link_speed_change_before_state_change':
include/linux/compiler_attributes.h:200:41: warning: statement will never be executed [-Wswitch-unreachable]
  200 | # define fallthrough                    __attribute__((__fallthrough__))
      |                                         ^~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/../powerplay/hwmgr/smu7_hwmgr.c:3706:4: note: in expansion of macro 'fallthrough'
 3706 |    fallthrough;
      |    ^~~~~~~~~~~

Introduced by commit

  e86efa063cd1 ("AMD POWERPLAY: Use fallthrough;")

-- 
Cheers,
Stephen Rothwell

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[PATCH] drm/amd/powerplay: Move fallthrough; into containing #ifdef/#endif

[Joe Perches]

The automated conversion of /* fallthrough */ comments converted
a comment outside of an #ifdef/#endif case block that should be
inside the block.

Move the fallthrough inside the block to silence the warning.

Signed-off-by: Joe Perches <joe@perches.com>
---

On Fri, 2020-03-13 at 20:57 +1100, Stephen Rothwell wrote:
> Hi all,
> 
> After merging the amdgpu tree, today's linux-next build (powerpc
> allyesconfig) produced this warning:
> 
> In file included from include/linux/compiler_types.h:59,
>                  from <command-line>:
> drivers/gpu/drm/amd/amdgpu/../powerplay/hwmgr/smu7_hwmgr.c: In function 'smu7_request_link_speed_change_before_state_change':
> include/linux/compiler_attributes.h:200:41: warning: statement will never be executed [-Wswitch-unreachable]
>   200 | # define fallthrough                    __attribute__((__fallthrough__))
>       |                                         ^~~~~~~~~~~~~
> drivers/gpu/drm/amd/amdgpu/../powerplay/hwmgr/smu7_hwmgr.c:3706:4: note: in expansion of macro 'fallthrough'
>  3706 |    fallthrough;
>       |    ^~~~~~~~~~~
> 
> Introduced by commit
> 
>   e86efa063cd1 ("AMD POWERPLAY: Use fallthrough;")

This is also one of the #ifdef/#endif pairs
where the fallthrough is outside of the #endif.

https://lore.kernel.org/lkml/cover.1584040050.git.joe@perches.com/

Here is a delta patch for this.
Let me know if another form is needed.

 drivers/gpu/drm/amd/powerplay/hwmgr/smu7_hwmgr.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/powerplay/hwmgr/smu7_hwmgr.c b/drivers/gpu/drm/amd/powerplay/hwmgr/smu7_hwmgr.c
index fc5236c..774048 100644
--- a/drivers/gpu/drm/amd/powerplay/hwmgr/smu7_hwmgr.c
+++ b/drivers/gpu/drm/amd/powerplay/hwmgr/smu7_hwmgr.c
@@ -3702,8 +3702,8 @@ static int smu7_request_link_speed_change_before_state_change(
 		case PP_PCIEGen2:
 			if (0 == amdgpu_acpi_pcie_performance_request(hwmgr->adev, PCIE_PERF_REQ_GEN2, false))
 				break;
-#endif
 			fallthrough;
+#endif
 		default:
 			data->force_pcie_gen = smu7_get_current_pcie_speed(hwmgr);
 			break;
-- 
2.24.0

Re: [PATCH] drm/amd/powerplay: Move fallthrough; into containing #ifdef/#endif

[Alex Deucher]

On Fri, Mar 13, 2020 at 8:59 AM Joe Perches <joe@perches.com> wrote:
>
> The automated conversion of /* fallthrough */ comments converted
> a comment outside of an #ifdef/#endif case block that should be
> inside the block.
>
> Move the fallthrough inside the block to silence the warning.
>
> Signed-off-by: Joe Perches <joe@perches.com>

Applied.  Thanks!

Alex

> ---
>
> On Fri, 2020-03-13 at 20:57 +1100, Stephen Rothwell wrote:
> > Hi all,
> >
> > After merging the amdgpu tree, today's linux-next build (powerpc
> > allyesconfig) produced this warning:
> >
> > In file included from include/linux/compiler_types.h:59,
> >                  from <command-line>:
> > drivers/gpu/drm/amd/amdgpu/../powerplay/hwmgr/smu7_hwmgr.c: In function 'smu7_request_link_speed_change_before_state_change':
> > include/linux/compiler_attributes.h:200:41: warning: statement will never be executed [-Wswitch-unreachable]
> >   200 | # define fallthrough                    __attribute__((__fallthrough__))
> >       |                                         ^~~~~~~~~~~~~
> > drivers/gpu/drm/amd/amdgpu/../powerplay/hwmgr/smu7_hwmgr.c:3706:4: note: in expansion of macro 'fallthrough'
> >  3706 |    fallthrough;
> >       |    ^~~~~~~~~~~
> >
> > Introduced by commit
> >
> >   e86efa063cd1 ("AMD POWERPLAY: Use fallthrough;")
>
> This is also one of the #ifdef/#endif pairs
> where the fallthrough is outside of the #endif.
>
> https://lore.kernel.org/lkml/cover.1584040050.git.joe@perches.com/
>
> Here is a delta patch for this.
> Let me know if another form is needed.
>
>  drivers/gpu/drm/amd/powerplay/hwmgr/smu7_hwmgr.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/powerplay/hwmgr/smu7_hwmgr.c b/drivers/gpu/drm/amd/powerplay/hwmgr/smu7_hwmgr.c
> index fc5236c..774048 100644
> --- a/drivers/gpu/drm/amd/powerplay/hwmgr/smu7_hwmgr.c
> +++ b/drivers/gpu/drm/amd/powerplay/hwmgr/smu7_hwmgr.c
> @@ -3702,8 +3702,8 @@ static int smu7_request_link_speed_change_before_state_change(
>                 case PP_PCIEGen2:
>                         if (0 == amdgpu_acpi_pcie_performance_request(hwmgr->adev, PCIE_PERF_REQ_GEN2, false))
>                                 break;
> -#endif
>                         fallthrough;
> +#endif
>                 default:
>                         data->force_pcie_gen = smu7_get_current_pcie_speed(hwmgr);
>                         break;
> --
> 2.24.0
>
>