diff mbox series

[v2,-next] net: mediatek: remove set but not used variable 'status'

Message ID 20190826013118.22720-1-maowenan@huawei.com
State Accepted
Delegated to: David Miller
Headers show
Series [v2,-next] net: mediatek: remove set but not used variable 'status' | expand

Commit Message

maowenan Aug. 26, 2019, 1:31 a.m. UTC
Fixes gcc '-Wunused-but-set-variable' warning:
drivers/net/ethernet/mediatek/mtk_eth_soc.c: In function mtk_handle_irq:
drivers/net/ethernet/mediatek/mtk_eth_soc.c:1951:6: warning: variable status set but not used [-Wunused-but-set-variable]

Fixes: 296c9120752b ("net: ethernet: mediatek: Add MT7628/88 SoC support")
Signed-off-by: Mao Wenan <maowenan@huawei.com>
---
 v2: change format of 'Fixes' tag.
 drivers/net/ethernet/mediatek/mtk_eth_soc.c | 2 --
 1 file changed, 2 deletions(-)

Comments

David Miller Aug. 26, 2019, 2:06 a.m. UTC | #1
From: Mao Wenan <maowenan@huawei.com>
Date: Mon, 26 Aug 2019 09:31:18 +0800

> Fixes gcc '-Wunused-but-set-variable' warning:
> drivers/net/ethernet/mediatek/mtk_eth_soc.c: In function mtk_handle_irq:
> drivers/net/ethernet/mediatek/mtk_eth_soc.c:1951:6: warning: variable status set but not used [-Wunused-but-set-variable]
> 
> Fixes: 296c9120752b ("net: ethernet: mediatek: Add MT7628/88 SoC support")
> Signed-off-by: Mao Wenan <maowenan@huawei.com>

Are you sure the register isn't being read in order to make some
hardware side effect happen?

Have you tested this on effected hardware?

I'm not applying this without definitive answers to these questions.
René van Dorst Aug. 26, 2019, 7:10 a.m. UTC | #2
Let's add Stefan to the conversation.
He is the author of this commit.

Quoting Mao Wenan <maowenan@huawei.com>:

> Fixes gcc '-Wunused-but-set-variable' warning:
> drivers/net/ethernet/mediatek/mtk_eth_soc.c: In function mtk_handle_irq:
> drivers/net/ethernet/mediatek/mtk_eth_soc.c:1951:6: warning:  
> variable status set but not used [-Wunused-but-set-variable]
>
> Fixes: 296c9120752b ("net: ethernet: mediatek: Add MT7628/88 SoC support")
> Signed-off-by: Mao Wenan <maowenan@huawei.com>
> ---
>  v2: change format of 'Fixes' tag.
>  drivers/net/ethernet/mediatek/mtk_eth_soc.c | 2 --
>  1 file changed, 2 deletions(-)
>
> diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c  
> b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
> index 8ddbb8d..bb7d623 100644
> --- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
> +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
> @@ -1948,9 +1948,7 @@ static irqreturn_t mtk_handle_irq_tx(int irq,  
> void *_eth)
>  static irqreturn_t mtk_handle_irq(int irq, void *_eth)
>  {
>  	struct mtk_eth *eth = _eth;
> -	u32 status;
>
> -	status = mtk_r32(eth, MTK_PDMA_INT_STATUS);

Hi Stefan,

You added an extra MTK_PDMA_INT_STATUS read in mtk_handle_irq()
Is that read necessary to work properly?

Greats,

René


>  	if (mtk_r32(eth, MTK_PDMA_INT_MASK) & MTK_RX_DONE_INT) {
>  		if (mtk_r32(eth, MTK_PDMA_INT_STATUS) & MTK_RX_DONE_INT)
>  			mtk_handle_irq_rx(irq, _eth);
> --
> 2.7.4
Stefan Roese Aug. 26, 2019, 7:27 a.m. UTC | #3
Hi!

On 26.08.19 09:10, René van Dorst wrote:
> Let's add Stefan to the conversation.
> He is the author of this commit.

Thanks Rene.
  
> Quoting Mao Wenan <maowenan@huawei.com>:
> 
>> Fixes gcc '-Wunused-but-set-variable' warning:
>> drivers/net/ethernet/mediatek/mtk_eth_soc.c: In function mtk_handle_irq:
>> drivers/net/ethernet/mediatek/mtk_eth_soc.c:1951:6: warning:
>> variable status set but not used [-Wunused-but-set-variable]
>>
>> Fixes: 296c9120752b ("net: ethernet: mediatek: Add MT7628/88 SoC support")
>> Signed-off-by: Mao Wenan <maowenan@huawei.com>
>> ---
>>   v2: change format of 'Fixes' tag.
>>   drivers/net/ethernet/mediatek/mtk_eth_soc.c | 2 --
>>   1 file changed, 2 deletions(-)
>>
>> diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
>> b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
>> index 8ddbb8d..bb7d623 100644
>> --- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
>> +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
>> @@ -1948,9 +1948,7 @@ static irqreturn_t mtk_handle_irq_tx(int irq,
>> void *_eth)
>>   static irqreturn_t mtk_handle_irq(int irq, void *_eth)
>>   {
>>   	struct mtk_eth *eth = _eth;
>> -	u32 status;
>>
>> -	status = mtk_r32(eth, MTK_PDMA_INT_STATUS);
> 
> Hi Stefan,
> 
> You added an extra MTK_PDMA_INT_STATUS read in mtk_handle_irq()
> Is that read necessary to work properly?

No, its not needed. This read must have "slipped in" from some earlier
patch versions and I forgot to remove it later. Thanks for catching it.

Reviewed-by: Stefan Roese <sr@denx.de>

Thanks,
Stefan
David Miller Aug. 28, 2019, 3:48 a.m. UTC | #4
From: Mao Wenan <maowenan@huawei.com>
Date: Mon, 26 Aug 2019 09:31:18 +0800

> Fixes gcc '-Wunused-but-set-variable' warning:
> drivers/net/ethernet/mediatek/mtk_eth_soc.c: In function mtk_handle_irq:
> drivers/net/ethernet/mediatek/mtk_eth_soc.c:1951:6: warning: variable status set but not used [-Wunused-but-set-variable]
> 
> Fixes: 296c9120752b ("net: ethernet: mediatek: Add MT7628/88 SoC support")
> Signed-off-by: Mao Wenan <maowenan@huawei.com>

Applied to net-next.
diff mbox series

Patch

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index 8ddbb8d..bb7d623 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -1948,9 +1948,7 @@  static irqreturn_t mtk_handle_irq_tx(int irq, void *_eth)
 static irqreturn_t mtk_handle_irq(int irq, void *_eth)
 {
 	struct mtk_eth *eth = _eth;
-	u32 status;
 
-	status = mtk_r32(eth, MTK_PDMA_INT_STATUS);
 	if (mtk_r32(eth, MTK_PDMA_INT_MASK) & MTK_RX_DONE_INT) {
 		if (mtk_r32(eth, MTK_PDMA_INT_STATUS) & MTK_RX_DONE_INT)
 			mtk_handle_irq_rx(irq, _eth);