2021-05-12 08:58:29

by Yang Li

Subject: [PATCH v2] platform/x86: drop unneeded assignment in host_control_smi()

Making '==' operation with ESM_STATUS_CMD_UNSUCCESSFUL directly
after calling the function inb() is more efficient, so assignment
to 'cmd_status' is redundant.

Eliminate the following clang_analyzer warning:
drivers/platform/x86/dell/dcdbas.c:397:11: warning: Although the value
stored to 'cmd_status' is used in the enclosing expression, the value
is never actually read from 'cmd_status'

No functional change.

Reported-by: Abaci Robot <[email protected]>
Signed-off-by: Yang Li <[email protected]>
---

Change in v2
--According to Hans's suggestion, store the inb() value into the s8.
https://lore.kernel.org/patchwork/patch/1419026/

drivers/platform/x86/dell/dcdbas.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/platform/x86/dell/dcdbas.c b/drivers/platform/x86/dell/dcdbas.c
index d513a59..28447c1 100644
--- a/drivers/platform/x86/dell/dcdbas.c
+++ b/drivers/platform/x86/dell/dcdbas.c
@@ -394,8 +394,7 @@ static int host_control_smi(void)

/* wait a few to see if it executed */
num_ticks = TIMEOUT_USEC_SHORT_SEMA_BLOCKING;
- while ((cmd_status = inb(PCAT_APM_STATUS_PORT))
- == ESM_STATUS_CMD_UNSUCCESSFUL) {
+ while ((s8)inb(PCAT_APM_STATUS_PORT) == ESM_STATUS_CMD_UNSUCCESSFUL) {
num_ticks--;
if (num_ticks == EXPIRED_TIMER)
return -ETIME;
--
1.8.3.1

2021-05-19 21:14:43

by Hans de Goede

Subject: Re: [PATCH v2] platform/x86: drop unneeded assignment in host_control_smi()

Hi,

On 5/12/21 10:57 AM, Yang Li wrote:
> Making '==' operation with ESM_STATUS_CMD_UNSUCCESSFUL directly
> after calling the function inb() is more efficient, so assignment
> to 'cmd_status' is redundant.
>
> Eliminate the following clang_analyzer warning:
> drivers/platform/x86/dell/dcdbas.c:397:11: warning: Although the value
> stored to 'cmd_status' is used in the enclosing expression, the value
> is never actually read from 'cmd_status'
>
> No functional change.
>
> Reported-by: Abaci Robot <[email protected]>
> Signed-off-by: Yang Li <[email protected]>

Thank you for your patch, I've applied this patch to my review-hans
branch:
https://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86.git/log/?h=review-hans

Note it will show up in my review-hans branch once I've pushed my
local branch there, which might take a while.

Once I've run some tests on this branch the patches there will be
added to the platform-drivers-x86/for-next branch and eventually
will be included in the pdx86 pull-request to Linus for the next
merge-window.

Regards,

Hans

> ---
>
> Change in v2
> --According to Hans's suggestion, store the inb() value into the s8.
> https://lore.kernel.org/patchwork/patch/1419026/
>
> drivers/platform/x86/dell/dcdbas.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/platform/x86/dell/dcdbas.c b/drivers/platform/x86/dell/dcdbas.c
> index d513a59..28447c1 100644
> --- a/drivers/platform/x86/dell/dcdbas.c
> +++ b/drivers/platform/x86/dell/dcdbas.c
> @@ -394,8 +394,7 @@ static int host_control_smi(void)
>
> /* wait a few to see if it executed */
> num_ticks = TIMEOUT_USEC_SHORT_SEMA_BLOCKING;
> - while ((cmd_status = inb(PCAT_APM_STATUS_PORT))
> - == ESM_STATUS_CMD_UNSUCCESSFUL) {
> + while ((s8)inb(PCAT_APM_STATUS_PORT) == ESM_STATUS_CMD_UNSUCCESSFUL) {
> num_ticks--;
> if (num_ticks == EXPIRED_TIMER)
> return -ETIME;
>