Re: [PATCH net-next 1/1] forcedeth: remove unused variable

[David Miller <davem@davemloft.net>]

From: Zhu Yanjun <yanjun.zhu@oracle.com>
Date: Mon, 15 Jan 2018 00:32:22 -0500

> The variable miistat is not used. So it is removed.
> 
> CC: Srinivas Eeda <srinivas.eeda@oracle.com>
> CC: Joe Jin <joe.jin@oracle.com>
> CC: Junxiao Bi <junxiao.bi@oracle.com>
> Signed-off-by: Zhu Yanjun <yanjun.zhu@oracle.com>
> ---
>  drivers/net/ethernet/nvidia/forcedeth.c | 7 ++-----
>  1 file changed, 2 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/net/ethernet/nvidia/forcedeth.c b/drivers/net/ethernet/nvidia/forcedeth.c
> index 21e15cb..c518f8c 100644
> --- a/drivers/net/ethernet/nvidia/forcedeth.c
> +++ b/drivers/net/ethernet/nvidia/forcedeth.c
> @@ -5510,11 +5510,8 @@ static int nv_open(struct net_device *dev)
>  	/* One manual link speed update: Interrupts are enabled, future link
>  	 * speed changes cause interrupts and are handled by nv_link_irq().
>  	 */
> -	{
> -		u32 miistat;
> -		miistat = readl(base + NvRegMIIStatus);
> -		writel(NVREG_MIISTAT_MASK_ALL, base + NvRegMIIStatus);
> -	}
> +	writel(NVREG_MIISTAT_MASK_ALL, base + NvRegMIIStatus);
> +

The readl() may have side effects and be necessary to clear some state
in the register.  I don't think you can remove the readl() without
verifying this and making sure it really is not necessary.

I can't apply this patch, sorry.