From d17251269095d058c7bf463f6cfb4922ad357147 Mon Sep 17 00:00:00 2001 From: Quentin Schulz Date: Thu, 7 May 2026 12:37:12 +0200 Subject: [PATCH] net: SYS_RX_ETH_BUFFER defaults to 8 when CONFIG_FSL_ENETC=y drivers/net/fsl_enetc.h specifies ENETC_BD_CNT "buffer descriptors count must be a multiple of 8". This constant is set to CONFIG_SYS_RX_ETH_BUFFER which defaults to 4. All defconfigs enabling CONFIG_FSL_ENETC fortunately have it set to 8, according to ./tools/qconfig.py -l -f CONFIG_FSL_ENETC '~CONFIG_SYS_RX_ETH_BUFFER=8'. Let's make sure the default is sane by having it set to 8 when this driver is enabled. Note that originally[1] it was said EEPRO100 and 405 EMAC should be 8 or higher. 405 (PPC405?) support seems to have been dropped in commit b5e7c84f72ee ("ppc4xx: remove ASH405 board"), 11 years ago. Maybe there's something we can do for EEPRO100 though? Start all lines with a tab instead of spaces. Specify limitation for FSL_ENETC in the help text. [1] commit 53cf9435ccf9 ("- CFG_RX_ETH_BUFFER added.") Reviewed-by: Simon Glass Signed-off-by: Quentin Schulz --- net/Kconfig | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) diff --git a/net/Kconfig b/net/Kconfig index 171a88f8ed2..6be392c1564 100644 --- a/net/Kconfig +++ b/net/Kconfig @@ -280,12 +280,15 @@ config TFTP_BLOCKSIZE You can also activate CONFIG_IP_DEFRAG to set a larger block. config SYS_RX_ETH_BUFFER - int "Number of receive packet buffers" - default 4 - help - Defines the number of Ethernet receive buffers. On some Ethernet - controllers it is recommended to set this value to 8 or even higher, - since all buffers can be full shortly after enabling the interface on - high Ethernet traffic. + int "Number of receive packet buffers" + default 8 if FSL_ENETC + default 4 + help + Defines the number of Ethernet receive buffers. On some Ethernet + controllers (e.g. FSL_ENETC) it is recommended to set this value to 8 + or even higher, since all buffers can be full shortly after enabling + the interface on high Ethernet traffic. + + FSL_ENETC requires this value to be a multiple of 8. endif # if NET