diff options
| -rw-r--r-- | drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 20 |
1 files 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 c63099a77cc0..82375d34ad57 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -5040,13 +5040,27 @@ 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; } |