2021-04-26 10:13:08

by Jiapeng Chong

[permalink] [raw]
Subject: [PATCH] can: softing: Remove redundant variable ptr

Variable ptr is being assigned a value from a calculation
however the variable is never read, so this redundant variable
can be removed.

Cleans up the following clang-analyzer warning:

drivers/net/can/softing/softing_main.c:279:3: warning: Value stored to
'ptr' is never read [clang-analyzer-deadcode.DeadStores].

drivers/net/can/softing/softing_main.c:242:3: warning: Value stored to
'ptr' is never read [clang-analyzer-deadcode.DeadStores].

Reported-by: Abaci Robot <[email protected]>
Signed-off-by: Jiapeng Chong <[email protected]>
---
drivers/net/can/softing/softing_main.c | 2 --
1 file changed, 2 deletions(-)

diff --git a/drivers/net/can/softing/softing_main.c b/drivers/net/can/softing/softing_main.c
index c44f341..cfc1325 100644
--- a/drivers/net/can/softing/softing_main.c
+++ b/drivers/net/can/softing/softing_main.c
@@ -239,7 +239,6 @@ static int softing_handle_1(struct softing *card)
DPRAM_INFO_BUSSTATE2 : DPRAM_INFO_BUSSTATE]);
/* timestamp */
tmp_u32 = le32_to_cpup((void *)ptr);
- ptr += 4;
ktime = softing_raw2ktime(card, tmp_u32);

++netdev->stats.rx_errors;
@@ -276,7 +275,6 @@ static int softing_handle_1(struct softing *card)
ktime = softing_raw2ktime(card, tmp_u32);
if (!(msg.can_id & CAN_RTR_FLAG))
memcpy(&msg.data[0], ptr, 8);
- ptr += 8;
/* update socket */
if (cmd & CMD_ACK) {
/* acknowledge, was tx msg */
--
1.8.3.1


2021-04-26 12:49:36

by Marc Kleine-Budde

[permalink] [raw]
Subject: Re: [PATCH] can: softing: Remove redundant variable ptr

On 26.04.2021 18:08:16, Jiapeng Chong wrote:
> Variable ptr is being assigned a value from a calculation
> however the variable is never read,
^^^^^^^^^^^^^

This is not 100% correct.

The variable ptr is read from, see a line directly above the line this
patch removes.

> so this redundant variable can be removed.

This patch doesn't remove the variable.

> Cleans up the following clang-analyzer warning:
>
> drivers/net/can/softing/softing_main.c:279:3: warning: Value stored to
> 'ptr' is never read [clang-analyzer-deadcode.DeadStores].
>
> drivers/net/can/softing/softing_main.c:242:3: warning: Value stored to
> 'ptr' is never read [clang-analyzer-deadcode.DeadStores].

The clang warning is more precise: the value stored to ptr in the
calculations this patch removes is not used, so the calculation and the
assignment can be removed.

> Reported-by: Abaci Robot <[email protected]>
> Signed-off-by: Jiapeng Chong <[email protected]>
> ---
> drivers/net/can/softing/softing_main.c | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/drivers/net/can/softing/softing_main.c b/drivers/net/can/softing/softing_main.c
> index c44f341..cfc1325 100644
> --- a/drivers/net/can/softing/softing_main.c
> +++ b/drivers/net/can/softing/softing_main.c
> @@ -239,7 +239,6 @@ static int softing_handle_1(struct softing *card)
> DPRAM_INFO_BUSSTATE2 : DPRAM_INFO_BUSSTATE]);
> /* timestamp */
> tmp_u32 = le32_to_cpup((void *)ptr);
> - ptr += 4;
> ktime = softing_raw2ktime(card, tmp_u32);
>
> ++netdev->stats.rx_errors;
> @@ -276,7 +275,6 @@ static int softing_handle_1(struct softing *card)
> ktime = softing_raw2ktime(card, tmp_u32);
> if (!(msg.can_id & CAN_RTR_FLAG))
> memcpy(&msg.data[0], ptr, 8);
> - ptr += 8;
> /* update socket */
> if (cmd & CMD_ACK) {
> /* acknowledge, was tx msg */
> --
> 1.8.3.1
>
>

Marc

--
Pengutronix e.K. | Marc Kleine-Budde |
Embedded Linux | https://www.pengutronix.de |
Vertretung West/Dortmund | Phone: +49-231-2826-924 |
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