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Date: Fri, 15 Aug 2025 10:24:33 -0700
From: Jakub Kicinski <kuba@kernel.org>
To: Dragos Tatulea <dtatulea@nvidia.com>
Cc: <almasrymina@google.com>, <asml.silence@gmail.com>, "David S. Miller"
 <davem@davemloft.net>, Eric Dumazet <edumazet@google.com>, Paolo Abeni
 <pabeni@redhat.com>, Simon Horman <horms@kernel.org>, <cratiu@nvidia.com>,
 <tariqt@nvidia.com>, <parav@nvidia.com>, Christoph Hellwig
 <hch@infradead.org>, <netdev@vger.kernel.org>,
 <linux-kernel@vger.kernel.org>
Subject: Re: [RFC net-next v3 7/7] net: devmem: allow binding on rx queues
 with same MA devices
Message-ID: <20250815102433.740eb2a6@kernel.org>
In-Reply-To: <20250815110401.2254214-9-dtatulea@nvidia.com>
References: <20250815110401.2254214-2-dtatulea@nvidia.com>
	<20250815110401.2254214-9-dtatulea@nvidia.com>
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On Fri, 15 Aug 2025 14:03:48 +0300 Dragos Tatulea wrote:
> +		rxq_dma_dev =3D netdev_queue_get_dma_dev(netdev, rxq_idx);
> +		/* Multi-PF netdev queues can belong to different DMA devoces.
> +		 * Block this case.
> +		 */
> +		if (rxq_dma_dev && dma_dev && rxq_dma_dev !=3D dma_dev) {

Why rxq_dma_dev ? =F0=9F=A4=94=EF=B8=8F
Don't we want to error out if the first queue gave us a DMA dev but the
second gave us a NULL ?

> +			NL_SET_ERR_MSG(extack, "Can't bind to queues from different dma devic=
es");

_FMT the conflicting queue IDs into this?