Re: [PATCH net-next v4 7/7] net: devmem: allow binding on rx queues with same DMA devices

[Jakub Kicinski <kuba@kernel.org>]

On Wed, 20 Aug 2025 20:11:58 +0300 Dragos Tatulea wrote:
> +static struct device *netdev_nl_get_dma_dev(struct net_device *netdev,
> +					    unsigned long *rxq_bitmap,
> +					    struct netlink_ext_ack *extack)

break after type if it's long and multi line:

static struct device *
netdev_nl_get_dma_dev(struct net_device *netdev, unsigned long *rxq_bitmap,
		      struct netlink_ext_ack *extack)

> +{
> +	struct device *dma_dev = NULL;
> +	u32 rxq_idx, prev_rxq_idx;
> +
> +	for_each_set_bit(rxq_idx, rxq_bitmap, netdev->real_num_rx_queues) {
> +		struct device *rxq_dma_dev;
> +
> +		rxq_dma_dev = netdev_queue_get_dma_dev(netdev, rxq_idx);
> +		/* Multi-PF netdev queues can belong to different DMA devoces.

typo: devoces

> +		 * Block this case.
> +		 */
> +		if (dma_dev && rxq_dma_dev != dma_dev) {
> +			NL_SET_ERR_MSG_FMT(extack, "Queue %u has a different dma device than queue %u",

s/dma/DMA/
I think we may want to bubble up the Multi-PF thing from the comment to
the user. This could be quite confusing to people. How about:

	"DMA device mismatch between queue %u and %u (multi-PF device?)"