[PATCH] clk: qcom: gpucc-sm8350: Fix "initializer element is not constant" error

[PATCH] clk: qcom: gpucc-sm8350: Fix "initializer element is not constant" error

[Nathan Chancellor]

When building with clang or GCC older than 8, errors along the following
lines occur:

  drivers/clk/qcom/gpucc-sm8350.c:111:2: error: initializer element is not a compile-time constant
          gpu_cc_parent,
          ^~~~~~~~~~~~~
  drivers/clk/qcom/gpucc-sm8350.c:126:2: error: initializer element is not a compile-time constant
          gpu_cc_parent,
          ^~~~~~~~~~~~~
  2 errors generated.

The C standard allows an implementation to accept other forms of
constant expressions, which GCC 8+ has chosen to do, but it is not
required. To fix this error with clang and older supported versions of
GCC, use a macro so that the expression can be used in a designated
initializer.

Fixes: 160758b05ab1 ("clk: qcom: add support for SM8350 GPUCC")
Link: https://github.com/ClangBuiltLinux/linux/issues/1660
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
---
 drivers/clk/qcom/gpucc-sm8350.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/clk/qcom/gpucc-sm8350.c b/drivers/clk/qcom/gpucc-sm8350.c
index d13fa813d190..9390723f6e40 100644
--- a/drivers/clk/qcom/gpucc-sm8350.c
+++ b/drivers/clk/qcom/gpucc-sm8350.c
@@ -51,9 +51,9 @@ static const struct alpha_pll_config gpu_cc_pll0_config = {
 	.user_ctl_hi1_val = 0x00000000,
 };
 
-static const struct clk_parent_data gpu_cc_parent = {
-	.fw_name = "bi_tcxo",
-};
+#define GPU_CC_PARENT_INIT { .fw_name = "bi_txco", }
+
+static const struct clk_parent_data gpu_cc_parent = GPU_CC_PARENT_INIT;
 
 static struct clk_alpha_pll gpu_cc_pll0 = {
 	.offset = 0x0,
@@ -108,7 +108,7 @@ static const struct parent_map gpu_cc_parent_map_0[] = {
 };
 
 static const struct clk_parent_data gpu_cc_parent_data_0[] = {
-	gpu_cc_parent,
+	GPU_CC_PARENT_INIT,
 	{ .hw = &gpu_cc_pll0.clkr.hw },
 	{ .hw = &gpu_cc_pll1.clkr.hw },
 	{ .fw_name = "gcc_gpu_gpll0_clk_src" },
@@ -123,7 +123,7 @@ static const struct parent_map gpu_cc_parent_map_1[] = {
 };
 
 static const struct clk_parent_data gpu_cc_parent_data_1[] = {
-	gpu_cc_parent,
+	GPU_CC_PARENT_INIT,
 	{ .hw = &gpu_cc_pll1.clkr.hw },
 	{ .fw_name = "gcc_gpu_gpll0_clk_src" },
 	{ .fw_name = "gcc_gpu_gpll0_div_clk_src" },

base-commit: 0dd8e16bfbc003b009f843e75fae4046daa08fe9
-- 
2.37.0

Re: [PATCH] clk: qcom: gpucc-sm8350: Fix "initializer element is not constant" error

[Dmitry Baryshkov]

On Mon, 11 Jul 2022 at 19:30, Nathan Chancellor <nathan@kernel.org> wrote:
>
> When building with clang or GCC older than 8, errors along the following
> lines occur:
>
>   drivers/clk/qcom/gpucc-sm8350.c:111:2: error: initializer element is not a compile-time constant
>           gpu_cc_parent,
>           ^~~~~~~~~~~~~
>   drivers/clk/qcom/gpucc-sm8350.c:126:2: error: initializer element is not a compile-time constant
>           gpu_cc_parent,
>           ^~~~~~~~~~~~~
>   2 errors generated.
>
> The C standard allows an implementation to accept other forms of
> constant expressions, which GCC 8+ has chosen to do, but it is not
> required. To fix this error with clang and older supported versions of
> GCC, use a macro so that the expression can be used in a designated
> initializer.
>
> Fixes: 160758b05ab1 ("clk: qcom: add support for SM8350 GPUCC")
> Link: https://github.com/ClangBuiltLinux/linux/issues/1660
> Reported-by: kernel test robot <lkp@intel.com>
> Signed-off-by: Nathan Chancellor <nathan@kernel.org>
> ---
>  drivers/clk/qcom/gpucc-sm8350.c | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/clk/qcom/gpucc-sm8350.c b/drivers/clk/qcom/gpucc-sm8350.c
> index d13fa813d190..9390723f6e40 100644
> --- a/drivers/clk/qcom/gpucc-sm8350.c
> +++ b/drivers/clk/qcom/gpucc-sm8350.c
> @@ -51,9 +51,9 @@ static const struct alpha_pll_config gpu_cc_pll0_config = {
>         .user_ctl_hi1_val = 0x00000000,
>  };
>
> -static const struct clk_parent_data gpu_cc_parent = {
> -       .fw_name = "bi_tcxo",
> -};
> +#define GPU_CC_PARENT_INIT { .fw_name = "bi_txco", }

Please inline this macro. It adds no additional value in my opinion

> +
> +static const struct clk_parent_data gpu_cc_parent = GPU_CC_PARENT_INIT;
>
>  static struct clk_alpha_pll gpu_cc_pll0 = {
>         .offset = 0x0,
> @@ -108,7 +108,7 @@ static const struct parent_map gpu_cc_parent_map_0[] = {
>  };
>
>  static const struct clk_parent_data gpu_cc_parent_data_0[] = {
> -       gpu_cc_parent,
> +       GPU_CC_PARENT_INIT,
>         { .hw = &gpu_cc_pll0.clkr.hw },
>         { .hw = &gpu_cc_pll1.clkr.hw },
>         { .fw_name = "gcc_gpu_gpll0_clk_src" },
> @@ -123,7 +123,7 @@ static const struct parent_map gpu_cc_parent_map_1[] = {
>  };
>
>  static const struct clk_parent_data gpu_cc_parent_data_1[] = {
> -       gpu_cc_parent,
> +       GPU_CC_PARENT_INIT,
>         { .hw = &gpu_cc_pll1.clkr.hw },
>         { .fw_name = "gcc_gpu_gpll0_clk_src" },
>         { .fw_name = "gcc_gpu_gpll0_div_clk_src" },
>
> base-commit: 0dd8e16bfbc003b009f843e75fae4046daa08fe9
> --
> 2.37.0
>


-- 
With best wishes
Dmitry