From: Jonas Karlman Date: Mon, 9 Mar 2026 21:06:39 +0000 (+0000) Subject: net: lwip: Fix PBUF_POOL_BUFSIZE when PROT_TCP_LWIP is disabled X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=b3ee14ea6d233a507a7983ccb5f1328cc8d683c2;p=thirdparty%2Fu-boot.git net: lwip: Fix PBUF_POOL_BUFSIZE when PROT_TCP_LWIP is disabled The PBUF_POOL_BUFSIZE ends up being only 592 bytes, instead of 1514, when PROT_TCP_LWIP Kconfig option is disabled. This results in a full Ethernet frame requiring three PBUFs instead of just one. This happens because the PBUF_POOL_BUFSIZE constant depends on the value of a TCP_MSS constant, something that defaults to 536 when PROT_TCP_LWIP is disabled. PBUF_POOL_BUFSIZE = LWIP_MEM_ALIGN_SIZE(TCP_MSS + 40 + PBUF_LINK_HLEN) Ensure that a full Ethernet frame fits inside a single PBUF by moving the define of TCP_MSS outside the PROT_TCP_LWIP ifdef block. Fixes: 1c41a7afaa15 ("net: lwip: build lwIP") Acked-by: Jerome Forissier Signed-off-by: Jonas Karlman --- diff --git a/lib/lwip/u-boot/lwipopts.h b/lib/lwip/u-boot/lwipopts.h index e8a2c9d7a0a..1550870fa86 100644 --- a/lib/lwip/u-boot/lwipopts.h +++ b/lib/lwip/u-boot/lwipopts.h @@ -121,9 +121,13 @@ #define LWIP_UDP 0 #endif +/* + * PBUF_POOL_BUFSIZE is derived from TCP_MSS even when + * CONFIG_PROT_TCP_LWIP is not defined + */ +#define TCP_MSS 1460 #if defined(CONFIG_PROT_TCP_LWIP) #define LWIP_TCP 1 -#define TCP_MSS 1460 #define TCP_WND CONFIG_LWIP_TCP_WND #define LWIP_WND_SCALE 1 #define TCP_RCV_SCALE 0x7