[PATCH] PCI: shpchp: Remove unused assignment to variable rc

[PATCH] PCI: shpchp: Remove unused assignment to variable rc

[Krzysztof Wilczyński]

The value of the constant POWER_FAILURE assigned to the variable rc
after the power fault check is never used for anything within the body
of the board_added() function and it is also overridden later following
jump to the err_exit label with the return value from the slot_disable()
callback.

Since the value of rc is never used in any meaningful way the assignment
can be removed.

I believe the assignment of constant POWER_FAILURE to the rc variable
was initially taken from the file drivers/pci/hotplug/cpqphp_ctrl.c and
then used in the file pci/hotplug/shpchp_ctrl.c (the code base is very
similar) around the time of the Kernel version 2.6.4-rc1 when the
support for the Standard Hot Plug was first added, sadly the Git history
only goes as far as to commit 1da177e4c3f4 ("Linux-2.6.12-rc2").

Related:
  https://elixir.bootlin.com/linux/v2.6.4-rc1/source/drivers/pci/hotplug/shpchp_ctrl.c
  https://elixir.bootlin.com/linux/v2.6.4-rc1/source/drivers/pci/hotplug/cpqphp_ctrl.c

Addresses-Coverity-ID: 1226899 ("Unused value")
Signed-off-by: Krzysztof Wilczyński <kw@linux.com>
---
 drivers/pci/hotplug/shpchp_ctrl.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/pci/hotplug/shpchp_ctrl.c b/drivers/pci/hotplug/shpchp_ctrl.c
index 65502e3f7b4f..6a6705e0cf17 100644
--- a/drivers/pci/hotplug/shpchp_ctrl.c
+++ b/drivers/pci/hotplug/shpchp_ctrl.c
@@ -299,7 +299,6 @@ static int board_added(struct slot *p_slot)
 	if (p_slot->status == 0xFF) {
 		/* power fault occurred, but it was benign */
 		ctrl_dbg(ctrl, "%s: Power fault\n", __func__);
-		rc = POWER_FAILURE;
 		p_slot->status = 0;
 		goto err_exit;
 	}
-- 
2.28.0

Re: [PATCH] PCI: shpchp: Remove unused assignment to variable rc

[Bjorn Helgaas]

On Wed, Sep 23, 2020 at 02:52:25AM +0000, Krzysztof Wilczyński wrote:
> The value of the constant POWER_FAILURE assigned to the variable rc
> after the power fault check is never used for anything within the body
> of the board_added() function and it is also overridden later following
> jump to the err_exit label with the return value from the slot_disable()
> callback.
> 
> Since the value of rc is never used in any meaningful way the assignment
> can be removed.
> 
> I believe the assignment of constant POWER_FAILURE to the rc variable
> was initially taken from the file drivers/pci/hotplug/cpqphp_ctrl.c and
> then used in the file pci/hotplug/shpchp_ctrl.c (the code base is very
> similar) around the time of the Kernel version 2.6.4-rc1 when the
> support for the Standard Hot Plug was first added, sadly the Git history
> only goes as far as to commit 1da177e4c3f4 ("Linux-2.6.12-rc2").
> 
> Related:
>   https://elixir.bootlin.com/linux/v2.6.4-rc1/source/drivers/pci/hotplug/shpchp_ctrl.c
>   https://elixir.bootlin.com/linux/v2.6.4-rc1/source/drivers/pci/hotplug/cpqphp_ctrl.c
> 
> Addresses-Coverity-ID: 1226899 ("Unused value")
> Signed-off-by: Krzysztof Wilczyński <kw@linux.com>

Applied to pci/hotplug for v5.10, thanks!

> ---
>  drivers/pci/hotplug/shpchp_ctrl.c | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/drivers/pci/hotplug/shpchp_ctrl.c b/drivers/pci/hotplug/shpchp_ctrl.c
> index 65502e3f7b4f..6a6705e0cf17 100644
> --- a/drivers/pci/hotplug/shpchp_ctrl.c
> +++ b/drivers/pci/hotplug/shpchp_ctrl.c
> @@ -299,7 +299,6 @@ static int board_added(struct slot *p_slot)
>  	if (p_slot->status == 0xFF) {
>  		/* power fault occurred, but it was benign */
>  		ctrl_dbg(ctrl, "%s: Power fault\n", __func__);
> -		rc = POWER_FAILURE;
>  		p_slot->status = 0;
>  		goto err_exit;
>  	}
> -- 
> 2.28.0
>