[-next] net: hisilicon: fix the return value handle and remove redundant netdev_err() for platform_get_irq()

  There is no possible for platform_get_irq() to return 0
and the return value of platform_get_irq() is more sensible
to show the error reason.

And there is no need to call the netdev_err() function directly to print
a custom message when handling an error from platform_get_irq() function as
it is going to display an appropriate error message in case of a failure.

Signed-off-by: Ruan Jinjie <ruanjinjie@huawei.com>
---
 drivers/net/ethernet/hisilicon/hip04_eth.c    | 4 ++--
 drivers/net/ethernet/hisilicon/hisi_femac.c   | 4 ++--
 drivers/net/ethernet/hisilicon/hix5hd2_gmac.c | 5 ++---
 3 files changed, 6 insertions(+), 7 deletions(-)
  

On 7/31/2023 12:38 AM, Ruan Jinjie wrote:
> There is no possible for platform_get_irq() to return 0
> and the return value of platform_get_irq() is more sensible
> to show the error reason.
> 
> And there is no need to call the netdev_err() function directly to print
> a custom message when handling an error from platform_get_irq() function as
> it is going to display an appropriate error message in case of a failure.
> 
> Signed-off-by: Ruan Jinjie <ruanjinjie@huawei.com>

Makes sense

Reviewed-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
  

On Mon, 31 Jul 2023 15:38:58 +0800 Ruan Jinjie wrote:
> There is no possible for platform_get_irq() to return 0
> and the return value of platform_get_irq() is more sensible
> to show the error reason.
> 
> And there is no need to call the netdev_err() function directly to print
> a custom message when handling an error from platform_get_irq() function as
> it is going to display an appropriate error message in case of a failure.
> 
> Signed-off-by: Ruan Jinjie <ruanjinjie@huawei.com>

Dan, with the sample of one patch from you I just applied I induce 
that treating 0 as error and returning a -EINVAL in that case may 
be preferable here?

> diff --git a/drivers/net/ethernet/hisilicon/hip04_eth.c b/drivers/net/ethernet/hisilicon/hip04_eth.c
> index 50c3f5d6611f..ecf92a5d56bb 100644
> --- a/drivers/net/ethernet/hisilicon/hip04_eth.c
> +++ b/drivers/net/ethernet/hisilicon/hip04_eth.c
> @@ -960,8 +960,8 @@ static int hip04_mac_probe(struct platform_device *pdev)
>  	}
>  
>  	irq = platform_get_irq(pdev, 0);
> -	if (irq <= 0) {
> -		ret = -EINVAL;
> +	if (irq < 0) {
> +		ret = irq;
>  		goto init_fail;
>  	}
>  
> diff --git a/drivers/net/ethernet/hisilicon/hisi_femac.c b/drivers/net/ethernet/hisilicon/hisi_femac.c
> index ce2571c16e43..cb7b0293fe85 100644
> --- a/drivers/net/ethernet/hisilicon/hisi_femac.c
> +++ b/drivers/net/ethernet/hisilicon/hisi_femac.c
> @@ -862,8 +862,8 @@ static int hisi_femac_drv_probe(struct platform_device *pdev)
>  		goto out_disconnect_phy;
>  
>  	ndev->irq = platform_get_irq(pdev, 0);
> -	if (ndev->irq <= 0) {
> -		ret = -ENODEV;
> +	if (ndev->irq < 0) {
> +		ret = ndev->irq;
>  		goto out_disconnect_phy;
>  	}
>  
> diff --git a/drivers/net/ethernet/hisilicon/hix5hd2_gmac.c b/drivers/net/ethernet/hisilicon/hix5hd2_gmac.c
> index f867e9531117..26d22bb04b87 100644
> --- a/drivers/net/ethernet/hisilicon/hix5hd2_gmac.c
> +++ b/drivers/net/ethernet/hisilicon/hix5hd2_gmac.c
> @@ -1206,9 +1206,8 @@ static int hix5hd2_dev_probe(struct platform_device *pdev)
>  	}
>  
>  	ndev->irq = platform_get_irq(pdev, 0);
> -	if (ndev->irq <= 0) {
> -		netdev_err(ndev, "No irq resource\n");
> -		ret = -EINVAL;
> +	if (ndev->irq < 0) {
> +		ret = ndev->irq;
>  		goto out_phy_node;
>  	}
>
  

On Tue, Aug 01, 2023 at 02:43:47PM -0700, Jakub Kicinski wrote:
> On Mon, 31 Jul 2023 15:38:58 +0800 Ruan Jinjie wrote:
> > There is no possible for platform_get_irq() to return 0
> > and the return value of platform_get_irq() is more sensible
> > to show the error reason.
> > 
> > And there is no need to call the netdev_err() function directly to print
> > a custom message when handling an error from platform_get_irq() function as
> > it is going to display an appropriate error message in case of a failure.
> > 
> > Signed-off-by: Ruan Jinjie <ruanjinjie@huawei.com>
> 
> Dan, with the sample of one patch from you I just applied I induce
> that treating 0 as error and returning a -EINVAL in that case may
> be preferable here?

This patch is correct.

Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>

The comments for platform_get_irq() say it returns negatives on error
and that's also how the code is implemented.

Is zero an error code?  Historically, a lot of IRQ functions returned
0 on error and some of those haven't been replaced with new functions
that return negative error codes.  irq_of_parse_and_map() is an example
of this.  I've been meaning to make a complete list but apparently
that's the only one Smatch checks for.

Is zero a valid IRQ?  In upstream code the answer is no and it never
will be.  In this code the platform_get_irq_optional() will trigger a
warning for that.
	if (WARN(!ret, "0 is an invalid IRQ number\n"))
However there are some old out of tree arches where zero is a valid IRQ.

regards,
dan carpenter
  

Hello:

This patch was applied to netdev/net-next.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Mon, 31 Jul 2023 15:38:58 +0800 you wrote:
> There is no possible for platform_get_irq() to return 0
> and the return value of platform_get_irq() is more sensible
> to show the error reason.
> 
> And there is no need to call the netdev_err() function directly to print
> a custom message when handling an error from platform_get_irq() function as
> it is going to display an appropriate error message in case of a failure.
> 
> [...]

Here is the summary with links:
  - [-next] net: hisilicon: fix the return value handle and remove redundant netdev_err() for platform_get_irq()
    https://git.kernel.org/netdev/net-next/c/ae1d60c41e58

You are awesome, thank you!