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

2019-08-22 08:06:48

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

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 <[email protected]>
---
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

2019-08-24 21:23:00

by David Miller

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

From: Mao Wenan <[email protected]>
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.

2019-08-26 01:35:15

by Mao Wenan

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

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 <[email protected]>
---
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

2019-08-26 02:17:00

by David Miller

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

From: Mao Wenan <[email protected]>
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 <[email protected]>

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.

2019-08-26 07:28:49

by Stefan Roese

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

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 <[email protected]>:
>
>> 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 <[email protected]>
>> ---
>> 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 <[email protected]>

Thanks,
Stefan

2019-08-26 08:15:42

by René van Dorst

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

Let's add Stefan to the conversation.
He is the author of this commit.

Quoting Mao Wenan <[email protected]>:

> 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 <[email protected]>
> ---
> 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

2019-08-28 03:49:28

by David Miller

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