On 04/25, Masahiro Yamada wrote:
> We cannot assign any value to an array type variable. So,
>
> hw_data->hws = kcalloc(hw_data->num, sizeof(struct clk_hw *),
> GFP_KERNEL);
>
> fails with "invalid use of flexible array member" error.
That's good. We don't want assignment to the hws member of this
structure to happen from an allocation like kcalloc.
>
> There are two ways to fix this issue.
>
> [1] Make it a double-pointer
> struct clk_hw_onecell_data {
> size_t num;
> struct clk_hw **hws;
> };
>
> This works as struct clk_onecell_data does.
True we could go back to the old style with two allocations.
>
> [2] Make it a zero-sized array
> struct clk_hw_onecell_data {
> size_t num;
> struct clk_hw *hws[0];
> };
>
> This allows one-shot memory allocation like this:
>
> hw_data = kmalloc(sizeof(*hw_data) + clk_num * sizeof(struct clk_hw *),
> GFP_KERNEL);
>
Good, that was possible before this patch wasn't it?
> This commit adopts [2] because it looks like Stephen's intention
> (he moved hws[] to the bottom of struct clk_hw_onecell_data).
>
> Fixes: 0861e5b8cf80 ("clk: Add clk_hw OF clk providers")
> Signed-off-by: Masahiro Yamada <yamada.masah...@socionext.com>
> ---
>
> include/linux/clk-provider.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
> index fd2ccd5..1850e25 100644
> --- a/include/linux/clk-provider.h
> +++ b/include/linux/clk-provider.h
> @@ -769,7 +769,7 @@ struct clk_onecell_data {
>
> struct clk_hw_onecell_data {
> size_t num;
> - struct clk_hw *hws[];
> + struct clk_hw *hws[0];
I'm totally lost now. Isn't a flex array with [] or with [0] the
same? The latter being a GCC extension while the former being a
C99 standard?
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