netdev - Re: [patchlet] r8169: fix napi_schedule_irqoff() called with irqs enabled warning

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Date:   Fri, 16 Oct 2020 13:34:55 +0200
From:   Heiner Kallweit <hkallweit1@...il.com>
To:     Mike Galbraith <efault@....de>, netdev <netdev@...r.kernel.org>
Cc:     Realtek linux nic maintainers <nic_swsd@...ltek.com>
Subject: Re: [patchlet] r8169: fix napi_schedule_irqoff() called with irqs
 enabled warning

On 16.10.2020 13:26, Mike Galbraith wrote:
> 
> When the kernel is built with PREEMPT_RT or booted with threadirqs,
> irqs are not disabled when rtl8169_interrupt() is called, inspiring
> __raise_softirq_irqoff() to gripe.  Use plain napi_schedule().
> 

I'm aware of the topic, but missing the benefits of the irqoff version
unconditionally doesn't seem to be the best option. See also:
https://lore.kernel.org/linux-arm-kernel/20201008162749.860521-1-john@metanate.com/
Needed is a function that dynamically picks the right version.

> Signed-off-by: Mike Galbraith <efault@....de>
> ---
>  drivers/net/ethernet/realtek/r8169_main.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> --- a/drivers/net/ethernet/realtek/r8169_main.c
> +++ b/drivers/net/ethernet/realtek/r8169_main.c
> @@ -4573,7 +4573,7 @@ static irqreturn_t rtl8169_interrupt(int
>  	}
> 
>  	rtl_irq_disable(tp);
> -	napi_schedule_irqoff(&tp->napi);
> +	napi_schedule(&tp->napi);
>  out:
>  	rtl_ack_events(tp, status);
> 
>