On 18-11-2025 09:16, Jakub Kicinski wrote:

On Fri, 14 Nov 2025 13:16:42 -0800 Aditya Garg wrote:

quoted

The MANA hardware supports a maximum of 30 scatter-gather entries (SGEs)
per TX WQE. Exceeding this limit can cause TX failures.
Add ndo_features_check() callback to validate SKB layout before
transmission. For GSO SKBs that would exceed the hardware SGE limit, clear
NETIF_F_GSO_MASK to enforce software segmentation in the stack.
Add a fallback in mana_start_xmit() to linearize non-GSO SKBs that still
exceed the SGE limit.

quoted

+	BUILD_BUG_ON(MAX_TX_WQE_SGL_ENTRIES != MANA_MAX_TX_WQE_SGL_ENTRIES);
+#if (MAX_SKB_FRAGS + 2 > MANA_MAX_TX_WQE_SGL_ENTRIES)
+	if (skb_shinfo(skb)->nr_frags + 2 > MAX_TX_WQE_SGL_ENTRIES) {

nit: please try to avoid the use of ifdef if you can. This helps to
avoid build breakage sneaking in as this code will be compiled out
on default config on all platforms.

Instead you should be able to simply add the static condition to the
if statement:

	if (MAX_SKB_FRAGS + 2 > MANA_MAX_TX_WQE_SGL_ENTRIES &&
	    skb_shinfo(skb)->nr_frags + 2 > MAX_TX_WQE_SGL_ENTRIES) {

and let the compiler (rather than preprocessor) eliminate this if ()
block.

Thanks for review and explanation Jakub, I will incorporate this change 
in next revision.

Regards,
Aditya