linux-kernel - [PATCH v2] platform/x86: drop unneeded assignment in host_control

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Date:   Wed, 12 May 2021 16:57:05 +0800
From:   Yang Li <yang.lee@...ux.alibaba.com>
To:     hdegoede@...hat.com
Cc:     stuart.w.hayes@...il.com, mgross@...ux.intel.com,
        platform-driver-x86@...r.kernel.org, linux-kernel@...r.kernel.org,
        Yang Li <yang.lee@...ux.alibaba.com>
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 <abaci@...ux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@...ux.alibaba.com>
---

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