[PATCH 0/2] drm/amdgpu: Fix instances of -Wunused-const-variable with CONFIG_DEBUG_FS=n

[PATCH 0/2] drm/amdgpu: Fix instances of -Wunused-const-variable with CONFIG_DEBUG_FS=n

[Nathan Chancellor]

Hi all,

After commit a25a9dae2067 ("drm/amd/amdgpu: enable W=1 for amdgpu"),
I see a few instances of -Wunused-const-variable with configurations
that do not enable CONFIG_DEBUG_FS, such as Alpine Linux's. This series
includes two patches to resolve each warning I see.

---
Nathan Chancellor (2):
      drm/amdgpu: Remove CONFIG_DEBUG_FS guard around body of amdgpu_rap_debugfs_init()
      drm/amdgpu: Move clocks closer to its only usage in amdgpu_parse_cg_state()

 drivers/gpu/drm/amd/amdgpu/amdgpu_rap.c |  2 -
 drivers/gpu/drm/amd/pm/amdgpu_pm.c      | 76 ++++++++++++++++-----------------
 2 files changed, 38 insertions(+), 40 deletions(-)
---
base-commit: d297eedf83f5af96751c0da1e4355c19244a55a2
change-id: 20230615-amdgpu-wunused-const-variable-wo-debugfs-308ce8e17329

Best regards,
-- 
Nathan Chancellor <nathan@kernel.org>

[PATCH 1/2] drm/amdgpu: Remove CONFIG_DEBUG_FS guard around body of amdgpu_rap_debugfs_init()

[Nathan Chancellor]

After commit a25a9dae2067 ("drm/amd/amdgpu: enable W=1 for amdgpu"),
there is an instance of -Wunused-const-variable when CONFIG_DEBUG_FS is
disabled:

  drivers/gpu/drm/amd/amdgpu/amdgpu_rap.c:110:37: error: unused variable 'amdgpu_rap_debugfs_ops' [-Werror,-Wunused-const-variable]
    110 | static const struct file_operations amdgpu_rap_debugfs_ops = {
        |                                     ^
  1 error generated.

There is no reason for the body of this function to be guarded when
CONFIG_DEBUG_FS is disabled, as debugfs_create_file() is a stub that
just returns an error pointer in that situation. Remove the preprocessor
guards so that the variable never appears unused, while not changing
anything at run time.

Signed-off-by: Nathan Chancellor <nathan@kernel.org>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_rap.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_rap.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_rap.c
index 12010c988c8b..123bcf5c2bb1 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_rap.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_rap.c
@@ -116,7 +116,6 @@ static const struct file_operations amdgpu_rap_debugfs_ops = {
 
 void amdgpu_rap_debugfs_init(struct amdgpu_device *adev)
 {
-#if defined(CONFIG_DEBUG_FS)
 	struct drm_minor *minor = adev_to_drm(adev)->primary;
 
 	if (!adev->psp.rap_context.context.initialized)
@@ -124,5 +123,4 @@ void amdgpu_rap_debugfs_init(struct amdgpu_device *adev)
 
 	debugfs_create_file("rap_test", S_IWUSR, minor->debugfs_root,
 				adev, &amdgpu_rap_debugfs_ops);
-#endif
 }

-- 
2.41.0

[PATCH 2/2] drm/amdgpu: Move clocks closer to its only usage in amdgpu_parse_cg_state()

[Nathan Chancellor]

After commit a25a9dae2067 ("drm/amd/amdgpu: enable W=1 for amdgpu"),
there is an instance of -Wunused-const-variable when CONFIG_DEBUG_FS is
disabled:

  drivers/gpu/drm/amd/amdgpu/../pm/amdgpu_pm.c:38:34: error: unused variable 'clocks' [-Werror,-Wunused-const-variable]
     38 | static const struct cg_flag_name clocks[] = {
        |                                  ^
  1 error generated.

clocks is only used when CONFIG_DEBUG_FS is set, so move the definition
into the CONFIG_DEBUG_FS block right above its only usage to clear up
the warning.

Signed-off-by: Nathan Chancellor <nathan@kernel.org>
---
 drivers/gpu/drm/amd/pm/amdgpu_pm.c | 76 +++++++++++++++++++-------------------
 1 file changed, 38 insertions(+), 38 deletions(-)

diff --git a/drivers/gpu/drm/amd/pm/amdgpu_pm.c b/drivers/gpu/drm/amd/pm/amdgpu_pm.c
index a57952b93e73..386ccf11e657 100644
--- a/drivers/gpu/drm/amd/pm/amdgpu_pm.c
+++ b/drivers/gpu/drm/amd/pm/amdgpu_pm.c
@@ -35,44 +35,6 @@
 #include <linux/pm_runtime.h>
 #include <asm/processor.h>
 
-static const struct cg_flag_name clocks[] = {
-	{AMD_CG_SUPPORT_GFX_FGCG, "Graphics Fine Grain Clock Gating"},
-	{AMD_CG_SUPPORT_GFX_MGCG, "Graphics Medium Grain Clock Gating"},
-	{AMD_CG_SUPPORT_GFX_MGLS, "Graphics Medium Grain memory Light Sleep"},
-	{AMD_CG_SUPPORT_GFX_CGCG, "Graphics Coarse Grain Clock Gating"},
-	{AMD_CG_SUPPORT_GFX_CGLS, "Graphics Coarse Grain memory Light Sleep"},
-	{AMD_CG_SUPPORT_GFX_CGTS, "Graphics Coarse Grain Tree Shader Clock Gating"},
-	{AMD_CG_SUPPORT_GFX_CGTS_LS, "Graphics Coarse Grain Tree Shader Light Sleep"},
-	{AMD_CG_SUPPORT_GFX_CP_LS, "Graphics Command Processor Light Sleep"},
-	{AMD_CG_SUPPORT_GFX_RLC_LS, "Graphics Run List Controller Light Sleep"},
-	{AMD_CG_SUPPORT_GFX_3D_CGCG, "Graphics 3D Coarse Grain Clock Gating"},
-	{AMD_CG_SUPPORT_GFX_3D_CGLS, "Graphics 3D Coarse Grain memory Light Sleep"},
-	{AMD_CG_SUPPORT_MC_LS, "Memory Controller Light Sleep"},
-	{AMD_CG_SUPPORT_MC_MGCG, "Memory Controller Medium Grain Clock Gating"},
-	{AMD_CG_SUPPORT_SDMA_LS, "System Direct Memory Access Light Sleep"},
-	{AMD_CG_SUPPORT_SDMA_MGCG, "System Direct Memory Access Medium Grain Clock Gating"},
-	{AMD_CG_SUPPORT_BIF_MGCG, "Bus Interface Medium Grain Clock Gating"},
-	{AMD_CG_SUPPORT_BIF_LS, "Bus Interface Light Sleep"},
-	{AMD_CG_SUPPORT_UVD_MGCG, "Unified Video Decoder Medium Grain Clock Gating"},
-	{AMD_CG_SUPPORT_VCE_MGCG, "Video Compression Engine Medium Grain Clock Gating"},
-	{AMD_CG_SUPPORT_HDP_LS, "Host Data Path Light Sleep"},
-	{AMD_CG_SUPPORT_HDP_MGCG, "Host Data Path Medium Grain Clock Gating"},
-	{AMD_CG_SUPPORT_DRM_MGCG, "Digital Right Management Medium Grain Clock Gating"},
-	{AMD_CG_SUPPORT_DRM_LS, "Digital Right Management Light Sleep"},
-	{AMD_CG_SUPPORT_ROM_MGCG, "Rom Medium Grain Clock Gating"},
-	{AMD_CG_SUPPORT_DF_MGCG, "Data Fabric Medium Grain Clock Gating"},
-	{AMD_CG_SUPPORT_VCN_MGCG, "VCN Medium Grain Clock Gating"},
-	{AMD_CG_SUPPORT_HDP_DS, "Host Data Path Deep Sleep"},
-	{AMD_CG_SUPPORT_HDP_SD, "Host Data Path Shutdown"},
-	{AMD_CG_SUPPORT_IH_CG, "Interrupt Handler Clock Gating"},
-	{AMD_CG_SUPPORT_JPEG_MGCG, "JPEG Medium Grain Clock Gating"},
-	{AMD_CG_SUPPORT_REPEATER_FGCG, "Repeater Fine Grain Clock Gating"},
-	{AMD_CG_SUPPORT_GFX_PERF_CLK, "Perfmon Clock Gating"},
-	{AMD_CG_SUPPORT_ATHUB_MGCG, "Address Translation Hub Medium Grain Clock Gating"},
-	{AMD_CG_SUPPORT_ATHUB_LS, "Address Translation Hub Light Sleep"},
-	{0, NULL},
-};
-
 static const struct hwmon_temp_label {
 	enum PP_HWMON_TEMP channel;
 	const char *label;
@@ -3684,6 +3646,44 @@ static int amdgpu_debugfs_pm_info_pp(struct seq_file *m, struct amdgpu_device *a
 	return 0;
 }
 
+static const struct cg_flag_name clocks[] = {
+	{AMD_CG_SUPPORT_GFX_FGCG, "Graphics Fine Grain Clock Gating"},
+	{AMD_CG_SUPPORT_GFX_MGCG, "Graphics Medium Grain Clock Gating"},
+	{AMD_CG_SUPPORT_GFX_MGLS, "Graphics Medium Grain memory Light Sleep"},
+	{AMD_CG_SUPPORT_GFX_CGCG, "Graphics Coarse Grain Clock Gating"},
+	{AMD_CG_SUPPORT_GFX_CGLS, "Graphics Coarse Grain memory Light Sleep"},
+	{AMD_CG_SUPPORT_GFX_CGTS, "Graphics Coarse Grain Tree Shader Clock Gating"},
+	{AMD_CG_SUPPORT_GFX_CGTS_LS, "Graphics Coarse Grain Tree Shader Light Sleep"},
+	{AMD_CG_SUPPORT_GFX_CP_LS, "Graphics Command Processor Light Sleep"},
+	{AMD_CG_SUPPORT_GFX_RLC_LS, "Graphics Run List Controller Light Sleep"},
+	{AMD_CG_SUPPORT_GFX_3D_CGCG, "Graphics 3D Coarse Grain Clock Gating"},
+	{AMD_CG_SUPPORT_GFX_3D_CGLS, "Graphics 3D Coarse Grain memory Light Sleep"},
+	{AMD_CG_SUPPORT_MC_LS, "Memory Controller Light Sleep"},
+	{AMD_CG_SUPPORT_MC_MGCG, "Memory Controller Medium Grain Clock Gating"},
+	{AMD_CG_SUPPORT_SDMA_LS, "System Direct Memory Access Light Sleep"},
+	{AMD_CG_SUPPORT_SDMA_MGCG, "System Direct Memory Access Medium Grain Clock Gating"},
+	{AMD_CG_SUPPORT_BIF_MGCG, "Bus Interface Medium Grain Clock Gating"},
+	{AMD_CG_SUPPORT_BIF_LS, "Bus Interface Light Sleep"},
+	{AMD_CG_SUPPORT_UVD_MGCG, "Unified Video Decoder Medium Grain Clock Gating"},
+	{AMD_CG_SUPPORT_VCE_MGCG, "Video Compression Engine Medium Grain Clock Gating"},
+	{AMD_CG_SUPPORT_HDP_LS, "Host Data Path Light Sleep"},
+	{AMD_CG_SUPPORT_HDP_MGCG, "Host Data Path Medium Grain Clock Gating"},
+	{AMD_CG_SUPPORT_DRM_MGCG, "Digital Right Management Medium Grain Clock Gating"},
+	{AMD_CG_SUPPORT_DRM_LS, "Digital Right Management Light Sleep"},
+	{AMD_CG_SUPPORT_ROM_MGCG, "Rom Medium Grain Clock Gating"},
+	{AMD_CG_SUPPORT_DF_MGCG, "Data Fabric Medium Grain Clock Gating"},
+	{AMD_CG_SUPPORT_VCN_MGCG, "VCN Medium Grain Clock Gating"},
+	{AMD_CG_SUPPORT_HDP_DS, "Host Data Path Deep Sleep"},
+	{AMD_CG_SUPPORT_HDP_SD, "Host Data Path Shutdown"},
+	{AMD_CG_SUPPORT_IH_CG, "Interrupt Handler Clock Gating"},
+	{AMD_CG_SUPPORT_JPEG_MGCG, "JPEG Medium Grain Clock Gating"},
+	{AMD_CG_SUPPORT_REPEATER_FGCG, "Repeater Fine Grain Clock Gating"},
+	{AMD_CG_SUPPORT_GFX_PERF_CLK, "Perfmon Clock Gating"},
+	{AMD_CG_SUPPORT_ATHUB_MGCG, "Address Translation Hub Medium Grain Clock Gating"},
+	{AMD_CG_SUPPORT_ATHUB_LS, "Address Translation Hub Light Sleep"},
+	{0, NULL},
+};
+
 static void amdgpu_parse_cg_state(struct seq_file *m, u64 flags)
 {
 	int i;

-- 
2.41.0

Re: [PATCH 2/2] drm/amdgpu: Move clocks closer to its only usage in amdgpu_parse_cg_state()

[Alex Deucher]

Applied the series.  Thanks!

Alex

On Thu, Jun 15, 2023 at 1:06 PM Nathan Chancellor <nathan@kernel.org> wrote:
>
> After commit a25a9dae2067 ("drm/amd/amdgpu: enable W=1 for amdgpu"),
> there is an instance of -Wunused-const-variable when CONFIG_DEBUG_FS is
> disabled:
>
>   drivers/gpu/drm/amd/amdgpu/../pm/amdgpu_pm.c:38:34: error: unused variable 'clocks' [-Werror,-Wunused-const-variable]
>      38 | static const struct cg_flag_name clocks[] = {
>         |                                  ^
>   1 error generated.
>
> clocks is only used when CONFIG_DEBUG_FS is set, so move the definition
> into the CONFIG_DEBUG_FS block right above its only usage to clear up
> the warning.
>
> Signed-off-by: Nathan Chancellor <nathan@kernel.org>
> ---
>  drivers/gpu/drm/amd/pm/amdgpu_pm.c | 76 +++++++++++++++++++-------------------
>  1 file changed, 38 insertions(+), 38 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/pm/amdgpu_pm.c b/drivers/gpu/drm/amd/pm/amdgpu_pm.c
> index a57952b93e73..386ccf11e657 100644
> --- a/drivers/gpu/drm/amd/pm/amdgpu_pm.c
> +++ b/drivers/gpu/drm/amd/pm/amdgpu_pm.c
> @@ -35,44 +35,6 @@
>  #include <linux/pm_runtime.h>
>  #include <asm/processor.h>
>
> -static const struct cg_flag_name clocks[] = {
> -       {AMD_CG_SUPPORT_GFX_FGCG, "Graphics Fine Grain Clock Gating"},
> -       {AMD_CG_SUPPORT_GFX_MGCG, "Graphics Medium Grain Clock Gating"},
> -       {AMD_CG_SUPPORT_GFX_MGLS, "Graphics Medium Grain memory Light Sleep"},
> -       {AMD_CG_SUPPORT_GFX_CGCG, "Graphics Coarse Grain Clock Gating"},
> -       {AMD_CG_SUPPORT_GFX_CGLS, "Graphics Coarse Grain memory Light Sleep"},
> -       {AMD_CG_SUPPORT_GFX_CGTS, "Graphics Coarse Grain Tree Shader Clock Gating"},
> -       {AMD_CG_SUPPORT_GFX_CGTS_LS, "Graphics Coarse Grain Tree Shader Light Sleep"},
> -       {AMD_CG_SUPPORT_GFX_CP_LS, "Graphics Command Processor Light Sleep"},
> -       {AMD_CG_SUPPORT_GFX_RLC_LS, "Graphics Run List Controller Light Sleep"},
> -       {AMD_CG_SUPPORT_GFX_3D_CGCG, "Graphics 3D Coarse Grain Clock Gating"},
> -       {AMD_CG_SUPPORT_GFX_3D_CGLS, "Graphics 3D Coarse Grain memory Light Sleep"},
> -       {AMD_CG_SUPPORT_MC_LS, "Memory Controller Light Sleep"},
> -       {AMD_CG_SUPPORT_MC_MGCG, "Memory Controller Medium Grain Clock Gating"},
> -       {AMD_CG_SUPPORT_SDMA_LS, "System Direct Memory Access Light Sleep"},
> -       {AMD_CG_SUPPORT_SDMA_MGCG, "System Direct Memory Access Medium Grain Clock Gating"},
> -       {AMD_CG_SUPPORT_BIF_MGCG, "Bus Interface Medium Grain Clock Gating"},
> -       {AMD_CG_SUPPORT_BIF_LS, "Bus Interface Light Sleep"},
> -       {AMD_CG_SUPPORT_UVD_MGCG, "Unified Video Decoder Medium Grain Clock Gating"},
> -       {AMD_CG_SUPPORT_VCE_MGCG, "Video Compression Engine Medium Grain Clock Gating"},
> -       {AMD_CG_SUPPORT_HDP_LS, "Host Data Path Light Sleep"},
> -       {AMD_CG_SUPPORT_HDP_MGCG, "Host Data Path Medium Grain Clock Gating"},
> -       {AMD_CG_SUPPORT_DRM_MGCG, "Digital Right Management Medium Grain Clock Gating"},
> -       {AMD_CG_SUPPORT_DRM_LS, "Digital Right Management Light Sleep"},
> -       {AMD_CG_SUPPORT_ROM_MGCG, "Rom Medium Grain Clock Gating"},
> -       {AMD_CG_SUPPORT_DF_MGCG, "Data Fabric Medium Grain Clock Gating"},
> -       {AMD_CG_SUPPORT_VCN_MGCG, "VCN Medium Grain Clock Gating"},
> -       {AMD_CG_SUPPORT_HDP_DS, "Host Data Path Deep Sleep"},
> -       {AMD_CG_SUPPORT_HDP_SD, "Host Data Path Shutdown"},
> -       {AMD_CG_SUPPORT_IH_CG, "Interrupt Handler Clock Gating"},
> -       {AMD_CG_SUPPORT_JPEG_MGCG, "JPEG Medium Grain Clock Gating"},
> -       {AMD_CG_SUPPORT_REPEATER_FGCG, "Repeater Fine Grain Clock Gating"},
> -       {AMD_CG_SUPPORT_GFX_PERF_CLK, "Perfmon Clock Gating"},
> -       {AMD_CG_SUPPORT_ATHUB_MGCG, "Address Translation Hub Medium Grain Clock Gating"},
> -       {AMD_CG_SUPPORT_ATHUB_LS, "Address Translation Hub Light Sleep"},
> -       {0, NULL},
> -};
> -
>  static const struct hwmon_temp_label {
>         enum PP_HWMON_TEMP channel;
>         const char *label;
> @@ -3684,6 +3646,44 @@ static int amdgpu_debugfs_pm_info_pp(struct seq_file *m, struct amdgpu_device *a
>         return 0;
>  }
>
> +static const struct cg_flag_name clocks[] = {
> +       {AMD_CG_SUPPORT_GFX_FGCG, "Graphics Fine Grain Clock Gating"},
> +       {AMD_CG_SUPPORT_GFX_MGCG, "Graphics Medium Grain Clock Gating"},
> +       {AMD_CG_SUPPORT_GFX_MGLS, "Graphics Medium Grain memory Light Sleep"},
> +       {AMD_CG_SUPPORT_GFX_CGCG, "Graphics Coarse Grain Clock Gating"},
> +       {AMD_CG_SUPPORT_GFX_CGLS, "Graphics Coarse Grain memory Light Sleep"},
> +       {AMD_CG_SUPPORT_GFX_CGTS, "Graphics Coarse Grain Tree Shader Clock Gating"},
> +       {AMD_CG_SUPPORT_GFX_CGTS_LS, "Graphics Coarse Grain Tree Shader Light Sleep"},
> +       {AMD_CG_SUPPORT_GFX_CP_LS, "Graphics Command Processor Light Sleep"},
> +       {AMD_CG_SUPPORT_GFX_RLC_LS, "Graphics Run List Controller Light Sleep"},
> +       {AMD_CG_SUPPORT_GFX_3D_CGCG, "Graphics 3D Coarse Grain Clock Gating"},
> +       {AMD_CG_SUPPORT_GFX_3D_CGLS, "Graphics 3D Coarse Grain memory Light Sleep"},
> +       {AMD_CG_SUPPORT_MC_LS, "Memory Controller Light Sleep"},
> +       {AMD_CG_SUPPORT_MC_MGCG, "Memory Controller Medium Grain Clock Gating"},
> +       {AMD_CG_SUPPORT_SDMA_LS, "System Direct Memory Access Light Sleep"},
> +       {AMD_CG_SUPPORT_SDMA_MGCG, "System Direct Memory Access Medium Grain Clock Gating"},
> +       {AMD_CG_SUPPORT_BIF_MGCG, "Bus Interface Medium Grain Clock Gating"},
> +       {AMD_CG_SUPPORT_BIF_LS, "Bus Interface Light Sleep"},
> +       {AMD_CG_SUPPORT_UVD_MGCG, "Unified Video Decoder Medium Grain Clock Gating"},
> +       {AMD_CG_SUPPORT_VCE_MGCG, "Video Compression Engine Medium Grain Clock Gating"},
> +       {AMD_CG_SUPPORT_HDP_LS, "Host Data Path Light Sleep"},
> +       {AMD_CG_SUPPORT_HDP_MGCG, "Host Data Path Medium Grain Clock Gating"},
> +       {AMD_CG_SUPPORT_DRM_MGCG, "Digital Right Management Medium Grain Clock Gating"},
> +       {AMD_CG_SUPPORT_DRM_LS, "Digital Right Management Light Sleep"},
> +       {AMD_CG_SUPPORT_ROM_MGCG, "Rom Medium Grain Clock Gating"},
> +       {AMD_CG_SUPPORT_DF_MGCG, "Data Fabric Medium Grain Clock Gating"},
> +       {AMD_CG_SUPPORT_VCN_MGCG, "VCN Medium Grain Clock Gating"},
> +       {AMD_CG_SUPPORT_HDP_DS, "Host Data Path Deep Sleep"},
> +       {AMD_CG_SUPPORT_HDP_SD, "Host Data Path Shutdown"},
> +       {AMD_CG_SUPPORT_IH_CG, "Interrupt Handler Clock Gating"},
> +       {AMD_CG_SUPPORT_JPEG_MGCG, "JPEG Medium Grain Clock Gating"},
> +       {AMD_CG_SUPPORT_REPEATER_FGCG, "Repeater Fine Grain Clock Gating"},
> +       {AMD_CG_SUPPORT_GFX_PERF_CLK, "Perfmon Clock Gating"},
> +       {AMD_CG_SUPPORT_ATHUB_MGCG, "Address Translation Hub Medium Grain Clock Gating"},
> +       {AMD_CG_SUPPORT_ATHUB_LS, "Address Translation Hub Light Sleep"},
> +       {0, NULL},
> +};
> +
>  static void amdgpu_parse_cg_state(struct seq_file *m, u64 flags)
>  {
>         int i;
>
> --
> 2.41.0
>