| From 7d310a8e17bd6f8ad6ad7c23eafc7a4c828ba8b0 Mon Sep 17 00:00:00 2001 |
| From: Aaro Koskinen <aaro.koskinen@nokia.com> |
| Date: Wed, 27 Mar 2019 22:35:39 +0200 |
| Subject: net: stmmac: fix dropping of multi-descriptor RX frames |
| |
| [ Upstream commit 8ac0c24fe1c256af6644caf3d311029440ec2fbd ] |
| |
| Packets without the last descriptor set should be dropped early. If we |
| receive a frame larger than the DMA buffer, the HW will continue using the |
| next descriptor. Driver mistakes these as individual frames, and sometimes |
| a truncated frame (without the LD set) may look like a valid packet. |
| |
| This fixes a strange issue where the system replies to 4098-byte ping |
| although the MTU/DMA buffer size is set to 4096, and yet at the same |
| time it's logging an oversized packet. |
| |
| Signed-off-by: Aaro Koskinen <aaro.koskinen@nokia.com> |
| Signed-off-by: David S. Miller <davem@davemloft.net> |
| Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org> |
| --- |
| drivers/net/ethernet/stmicro/stmmac/enh_desc.c | 5 +++++ |
| 1 file changed, 5 insertions(+) |
| |
| diff --git a/drivers/net/ethernet/stmicro/stmmac/enh_desc.c b/drivers/net/ethernet/stmicro/stmmac/enh_desc.c |
| index c42ef6c729c0..5202d6ad7919 100644 |
| --- a/drivers/net/ethernet/stmicro/stmmac/enh_desc.c |
| +++ b/drivers/net/ethernet/stmicro/stmmac/enh_desc.c |
| @@ -201,6 +201,11 @@ static int enh_desc_get_rx_status(void *data, struct stmmac_extra_stats *x, |
| if (unlikely(rdes0 & RDES0_OWN)) |
| return dma_own; |
| |
| + if (unlikely(!(rdes0 & RDES0_LAST_DESCRIPTOR))) { |
| + stats->rx_length_errors++; |
| + return discard_frame; |
| + } |
| + |
| if (unlikely(rdes0 & RDES0_ERROR_SUMMARY)) { |
| if (unlikely(rdes0 & RDES0_DESCRIPTOR_ERROR)) { |
| x->rx_desc++; |
| -- |
| 2.20.1 |
| |
