[5/7] drm/amd/display: Use proper enum conversion functions

Submitted by Arnd Bergmann on July 9, 2019, 6:51 p.m.

Details

Message ID CAK8P3a1vEtrS7SbhCPVxoYBcroT+Hr3Q4LFs6AJJ8G8GVw5SVA@mail.gmail.com
State New
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Series "amdgpu clang warning fixes on next-20190703" ( rev: 2 ) in DRI devel

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Commit Message

Arnd Bergmann July 9, 2019, 6:51 p.m.
On Thu, Jul 4, 2019 at 7:52 AM Nathan Chancellor
<natechancellor@gmail.com> wrote:
>
> clang warns:
>
> drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm_pp_smu.c:336:8:
> warning: implicit conversion from enumeration type 'enum smu_clk_type'
> to different enumeration type 'enum amd_pp_clock_type'
> [-Wenum-conversion]
>                                         dc_to_smu_clock_type(clk_type),
>                                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm_pp_smu.c:421:14:
> warning: implicit conversion from enumeration type 'enum
> amd_pp_clock_type' to different enumeration type 'enum smu_clk_type'
> [-Wenum-conversion]
>                                         dc_to_pp_clock_type(clk_type),
>                                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> There are functions to properly convert between all of these types, use
> them so there are no longer any warnings.

I had a different solution for this one as well. The difference is that your
patch keeps the types and assumes that the functions do the right thing
(i.e. the warning was correct), while my version assumes that the code
works correctly, but the types are wrong (a false positive warning).

One of the two patches is correct, the other one is broken, but I have
no idea which one.

      Arnd

From 61316b80c852d103bb61e1ce9904002414600125 Mon Sep 17 00:00:00 2001
From: Arnd Bergmann <arnd@arndb.de>
Date: Mon, 8 Jul 2019 17:44:05 +0200
Subject: [PATCH] drm/amd/powerplay: fix one more incorrect enum conversion

Similar to a previous patch, this one converts the type from a
function argument of a different enum type:

drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm_pp_smu.c:336:8:
error: implicit conversion from enumeration type 'enum smu_clk_type'
to different enumeration type 'enum amd_pp_clock_type'
[-Werror,-Wenum-conversion]
                                          dc_to_smu_clock_type(clk_type),
                                          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/../powerplay/inc/amdgpu_smu.h:868:77: note:
expanded from macro 'smu_get_clock_by_type'
        ((smu)->funcs->get_clock_by_type ?
(smu)->funcs->get_clock_by_type((smu), (type), (clocks)) : 0)
                                           ~
            ^~~~
drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm_pp_smu.c:421:14:
error: implicit conversion from enumeration type 'enum
amd_pp_clock_type' to different enumeration type 'enum smu_clk_type'
[-Werror,-Wenum-conversion]

dc_to_pp_clock_type(clk_type),

^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/amd/amdgpu/../powerplay/inc/amdgpu_smu.h:872:111:
note: expanded from macro 'smu_get_clock_by_type_with_latency'

Add another type cast.

Fixes: e5e4e22391c2 ("drm/amd/powerplay: add interface to get clock by
type with latency for display (v2)")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

                        return true;
@@ -418,7 +418,7 @@ bool dm_pp_get_clock_levels_by_type_with_latency(
                        return false;
        } else if (adev->smu.ppt_funcs &&
adev->smu.ppt_funcs->get_clock_by_type_with_latency) {
                if (smu_get_clock_by_type_with_latency(&adev->smu,
-
dc_to_pp_clock_type(clk_type),
+                                                      (enum
smu_clk_type)dc_to_pp_clock_type(clk_type),
                                                       &pp_clks))
                        return false;
        }

Patch hide | download patch | download mbox

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_pp_smu.c
b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_pp_smu.c
index eac09bfe3be2..88e3f8456b1c 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_pp_smu.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_pp_smu.c
@@ -333,7 +333,7 @@  bool dm_pp_get_clock_levels_by_type(
                }
        } else if (adev->smu.funcs && adev->smu.funcs->get_clock_by_type) {
                if (smu_get_clock_by_type(&adev->smu,
-                                         dc_to_smu_clock_type(clk_type),
+                                         (enum
amd_pp_clock_type)dc_to_smu_clock_type(clk_type),
                                          &pp_clks)) {
                        get_default_clock_levels(clk_type, dc_clks);

Comments

On Tue, Jul 09, 2019 at 08:51:33PM +0200, Arnd Bergmann wrote:
> On Thu, Jul 4, 2019 at 7:52 AM Nathan Chancellor
> <natechancellor@gmail.com> wrote:
> >
> > clang warns:
> >
> > drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm_pp_smu.c:336:8:
> > warning: implicit conversion from enumeration type 'enum smu_clk_type'
> > to different enumeration type 'enum amd_pp_clock_type'
> > [-Wenum-conversion]
> >                                         dc_to_smu_clock_type(clk_type),
> >                                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm_pp_smu.c:421:14:
> > warning: implicit conversion from enumeration type 'enum
> > amd_pp_clock_type' to different enumeration type 'enum smu_clk_type'
> > [-Wenum-conversion]
> >                                         dc_to_pp_clock_type(clk_type),
> >                                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> >
> > There are functions to properly convert between all of these types, use
> > them so there are no longer any warnings.
> 
> I had a different solution for this one as well. The difference is that your
> patch keeps the types and assumes that the functions do the right thing
> (i.e. the warning was correct), while my version assumes that the code
> works correctly, but the types are wrong (a false positive warning).
> 
> One of the two patches is correct, the other one is broken, but I have
> no idea which one.
> 
>       Arnd

Indeed. I would personally argue that if using the correct conversion
functions (which are here to specifically avoid this type of warning)
causes issues, this code should probably not be using enumerated types
at all since the entire point is to enforce semantic correctness, not
just be a special way to represent small integer values, especially in
the case where the CLK values are completely different numerical values
in various enumerated types. I think enumerated type casts are ugly and
defeat the purpose of them but that's obviously just my opinion :)

Hopefully we can get some clarity on this soon.

Cheers,
Nathan