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Subject: Re: [PATCH net-next v3 18/19] net: ravb: Do not apply RX CSUM
 settings to hardware if the interface is down
To: Claudiu <claudiu.beznea@tuxon.dev>, <davem@davemloft.net>,
	<edumazet@google.com>, <kuba@kernel.org>, <pabeni@redhat.com>,
	<richardcochran@gmail.com>, <p.zabel@pengutronix.de>,
	<yoshihiro.shimoda.uh@renesas.com>, <wsa+renesas@sang-engineering.com>
CC: <netdev@vger.kernel.org>, <linux-renesas-soc@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>, <geert+renesas@glider.be>, Claudiu Beznea
	<claudiu.beznea.uj@bp.renesas.com>
References: <20240105082339.1468817-1-claudiu.beznea.uj@bp.renesas.com>
 <20240105082339.1468817-19-claudiu.beznea.uj@bp.renesas.com>
From: Sergey Shtylyov <s.shtylyov@omp.ru>
Organization: Open Mobile Platform
Message-ID: <045aa818-8f99-4150-0072-f17fdc6ced0b@omp.ru>
Date: Mon, 8 Jan 2024 23:34:28 +0300
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On 1/5/24 11:23 AM, Claudiu wrote:

> From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
> 
> Do not apply the RX CSUM settings to hardware if the interface is down. In
> case runtime PM is enabled, and while the interface is down, the IP will be
> in reset mode (as for some platforms disabling the clocks will switch the
> IP to reset mode, which will lead to losing registers content) and applying
> settings in reset mode is not an option. Instead, cache the RX CSUM
> settings and apply them in ravb_open() though ravb_emac_init().
> 
> Commit prepares for the addition of runtime PM.
> 
> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
[...]

> diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
> index 168b6208db37..e909960fbc30 100644
> --- a/drivers/net/ethernet/renesas/ravb_main.c
> +++ b/drivers/net/ethernet/renesas/ravb_main.c
> @@ -2342,6 +2342,9 @@ static void ravb_set_rx_csum(struct net_device *ndev, bool enable)
>  	struct ravb_private *priv = netdev_priv(ndev);
>  	unsigned long flags;
>  
> +	if (!(ndev->flags & IFF_UP))

   Well, I guess it's even OK to even write EDCMR in the reset mode... BUT
again, won't this race with pm_runtime_put_autosuspend() when its call gets
added to ravb_close()?

> +		return;
> +
>  	spin_lock_irqsave(&priv->lock, flags);
>  
>  	/* Disable TX and RX */

MBR, Sergey