qs+0x1b8/0x1fc ... To fix this, the PL bit-field in RDES3 register is used for all descriptors, whether it is the last descriptor or not. Fixes: ec222003bd94 ("net: stmmac: Prepare to add Split Header support") Reviewed-by: Jacob Keller Signed-off-by: Jie Zhang Link: https://patch.msgid.link/20260209225037.589130-1-jie.zhang@analog.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- .../net/ethernet/stmicro/stmmac/stmmac_main.c | 20 ++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index a379221b96a34..f98fd254315f6 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -5023,13 +5023,27 @@ static unsigned int stmmac_rx_buf2_len(struct stmmac_priv *priv, if (!priv->sph_active) return 0; - /* Not last descriptor */ - if (status & rx_not_ls) + /* For GMAC4, when split header is enabled, in some rare cases, the + * hardware does not fill buf2 of the first descriptor with payload. + * Thus we cannot assume buf2 is always fully filled if it is not + * the last descriptor. Otherwise, the length of buf2 of the second + * descriptor will be calculated wrong and cause an oops. + * + * If this is the last descriptor, 'plen' is the length of the + * received packet that was transferred to system memory. + * Otherwise, it is the accumulated number of bytes that have been + * transferred for the current packet. + * + * Thus 'plen - len' always gives the correct length of buf2. + */ + + /* Not GMAC4 and not last descriptor */ + if (priv->plat->core_type != DWMAC_CORE_GMAC4 && (status & rx_not_ls)) return priv->dma_conf.dma_buf_sz; + /* GMAC4 or last descriptor */ plen = stmmac_get_rx_frame_len(priv, p, coe); - /* Last descriptor */ return plen - len; } -- 2.51.0[PATCH 6.19 638/781] net: stmmac: fix oops when split header is enabledGreg Kroah-Hartman undefinedstable@vger.kernel.org undefined undefined undefined undefined undefined undefined¸ †—