[PATCH] clk: remove unneeded dead-store initialization

[PATCH] clk: remove unneeded dead-store initialization

[Lukas Bulwahn]

make clang-analyzer on x86_64 defconfig caught my attention with:

  drivers/clk/clk.c:423:19:
  warning: Value stored to 'parent' during its initialization is never read
  [clang-analyzer-deadcode.DeadStores]
          struct clk_core *parent = ERR_PTR(-ENOENT);
                           ^

Commit fc0c209c147f ("clk: Allow parents to be specified without string
names") introduced clk_core_fill_parent_index() with this unneeded
dead-store initialization.

So, simply remove this unneeded dead-store initialization to make
clang-analyzer happy.

As compilers will detect this unneeded assignment and optimize this anyway,
the resulting object code is identical before and after this change.

No functional change. No change to object code.

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
---
applies cleanly on current master and next-20201106

Stephen, Michael, please pick this minor non-urgent clean-up patch.

 drivers/clk/clk.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index f83dac54ed85..ba35bf35bcd3 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -420,7 +420,7 @@ static struct clk_core *clk_core_get(struct clk_core *core, u8 p_index)
 static void clk_core_fill_parent_index(struct clk_core *core, u8 index)
 {
 	struct clk_parent_map *entry = &core->parents[index];
-	struct clk_core *parent = ERR_PTR(-ENOENT);
+	struct clk_core *parent;
 
 	if (entry->hw) {
 		parent = entry->hw->core;
-- 
2.17.1

Re: [PATCH] clk: remove unneeded dead-store initialization

[Nathan Chancellor]

On Fri, Nov 06, 2020 at 10:48:20AM +0100, Lukas Bulwahn wrote:
> make clang-analyzer on x86_64 defconfig caught my attention with:
> 
>   drivers/clk/clk.c:423:19:
>   warning: Value stored to 'parent' during its initialization is never read
>   [clang-analyzer-deadcode.DeadStores]
>           struct clk_core *parent = ERR_PTR(-ENOENT);
>                            ^
> 
> Commit fc0c209c147f ("clk: Allow parents to be specified without string
> names") introduced clk_core_fill_parent_index() with this unneeded
> dead-store initialization.
> 
> So, simply remove this unneeded dead-store initialization to make
> clang-analyzer happy.
> 
> As compilers will detect this unneeded assignment and optimize this anyway,
> the resulting object code is identical before and after this change.
> 
> No functional change. No change to object code.
> 
> Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>

Indeed, parent is always assigned a new value before that one is read.

Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>

> ---
> applies cleanly on current master and next-20201106
> 
> Stephen, Michael, please pick this minor non-urgent clean-up patch.
> 
>  drivers/clk/clk.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
> index f83dac54ed85..ba35bf35bcd3 100644
> --- a/drivers/clk/clk.c
> +++ b/drivers/clk/clk.c
> @@ -420,7 +420,7 @@ static struct clk_core *clk_core_get(struct clk_core *core, u8 p_index)
>  static void clk_core_fill_parent_index(struct clk_core *core, u8 index)
>  {
>  	struct clk_parent_map *entry = &core->parents[index];
> -	struct clk_core *parent = ERR_PTR(-ENOENT);
> +	struct clk_core *parent;
>  
>  	if (entry->hw) {
>  		parent = entry->hw->core;
> -- 
> 2.17.1
> 

Re: [PATCH] clk: remove unneeded dead-store initialization

[Stephen Boyd]

Quoting Lukas Bulwahn (2020-11-06 01:48:20)
> make clang-analyzer on x86_64 defconfig caught my attention with:
> 
>   drivers/clk/clk.c:423:19:
>   warning: Value stored to 'parent' during its initialization is never read
>   [clang-analyzer-deadcode.DeadStores]
>           struct clk_core *parent = ERR_PTR(-ENOENT);
>                            ^
> 
> Commit fc0c209c147f ("clk: Allow parents to be specified without string
> names") introduced clk_core_fill_parent_index() with this unneeded
> dead-store initialization.
> 
> So, simply remove this unneeded dead-store initialization to make
> clang-analyzer happy.
> 
> As compilers will detect this unneeded assignment and optimize this anyway,
> the resulting object code is identical before and after this change.
> 
> No functional change. No change to object code.
> 
> Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
> ---

Applied to clk-next