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

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

[Mao Wenan]

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]

It is not used since commit 296c9120752b ("net: ethernet: mediatek: Add MT7628/88 SoC support")
Signed-off-by: Mao Wenan <maowenan@huawei.com>
---
 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);
 	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

Re: [PATCH -next] net: mediatek: remove set but not used variable 'status'

[David Miller]

From: Mao Wenan <maowenan@huawei.com>
Date: Thu, 22 Aug 2019 14:30:26 +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]
> 
> It is not used since commit 296c9120752b ("net: ethernet: mediatek: Add MT7628/88 SoC support")

This is not a standard commit tag, please use Fixes: or similar.

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

[Mao Wenan]

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);
 	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

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

[David Miller]

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.

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

[René van Dorst]

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

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

[Stefan Roese]

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

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

[David Miller]

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.