[PATCH] net/intel: improve Rx descriptor ring size checks

[Bruce Richardson]

On Mon, Dec 15, 2025 at 06:54:50PM +0100, Morten Brørup wrote:
> > From: Bruce Richardson [mailto:bruce.richardson at intel.com]
> > Sent: Monday, 15 December 2025 18.36
> > 
> > The default Rx ring size checks did not account for the fact that the
> > port would not work correctly if the Rx ring size was only twice the
> > free threshold size or less, so add in a new check for this. This would
> > generally only apply in cases where very small rings sizes are being
> > used, for example, with default Rx free thresh of 32, only ring size of
> > 64 would cause issues.
> > 
> > Signed-off-by: Bruce Richardson <bruce.richardson at intel.com>
> > ---
> 
> Does dev_info.rx_desc_lim.nb_min returned by rte_eth_dev_info_get() need correction too?
> 
The minimum number of descriptors stays the same, however, if choosing the
minimum number of descriptors you may need to reduce the rx_free_thresh
value.

/Bruce