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Date: Thu, 10 Jul 2025 06:37:29 -0700
From: Jakub Kicinski <kuba@kernel.org>
To: Gal Pressman <gal@nvidia.com>
Cc: "David S. Miller" <davem@davemloft.net>, Eric Dumazet
 <edumazet@google.com>, Paolo Abeni <pabeni@redhat.com>, Andrew Lunn
 <andrew+netdev@lunn.ch>, netdev@vger.kernel.org, Andrew Lunn
 <andrew@lunn.ch>, Simon Horman <horms@kernel.org>, Dragos Tatulea
 <dtatulea@nvidia.com>
Subject: Re: [PATCH net-next] ethtool: Fix set RXFH for drivers without RXFH
 fields support
Message-ID: <20250710063729.08ae71e6@kernel.org>
In-Reply-To: <a6341aa1-dd8b-4449-ba95-38bb067d6483@nvidia.com>
References: <20250709153251.360291-1-gal@nvidia.com>
	<20250709172508.5df4e5c9@kernel.org>
	<a6341aa1-dd8b-4449-ba95-38bb067d6483@nvidia.com>
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On Thu, 10 Jul 2025 14:17:11 +0300 Gal Pressman wrote:
> > We could add a:
> > 
> > 	if (WARN_ON(ops->supported_input_xfrm && !ops->get_rxfh_fields))
> > 		return -EINVAL;
> > 
> > into ethtool_check_ops() and we'd be both safe and slightly faster.  
> 
> This is a step further.
> 
> There could be a driver that allows setting of input xfrm but not rxfh
> fields. Failing the netdevice registration is different than skipping
> ethtool_check_flow_types().
> 
> Maybe there are no such devices and we shouldn't care?

Note that we're talking about the get. It's still perfectly fine for
the hypothetical driver to not support _changing_ the fields, the fields
be hardwired. But we need to know what fields the device is using to
validate the xfrm is correct.