ACS Feature is currently enabled for GMAC >= 4 but the llc_snap status
is never checked in descriptor rx_status callback. This will cause
stmmac to always strip packets even that ACS feature is already
stripping them.
Lets be safe and disable the ACS feature for GMAC >= 4 and always strip
the packets for this GMAC version.
Fixes: 477286b53f55 ("stmmac: add GMAC4 core support")
Signed-off-by: Jose Abreu <[email protected]>
Cc: David S. Miller <[email protected]>
Cc: Joao Pinto <[email protected]>
Cc: Giuseppe Cavallaro <[email protected]>
Cc: Alexandre Torgue <[email protected]>
---
Hi David,
Requesting this to go up for stable also. I think its for v4.7+ but if you
could cross-check it would be great! Let me know if you need any more
info for queueing this.
Thanks
---
drivers/net/ethernet/stmicro/stmmac/dwmac4.h | 2 +-
drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c | 7 -------
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 7 ++++++-
3 files changed, 7 insertions(+), 9 deletions(-)
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4.h
b/drivers/net/ethernet/stmicro/stmmac/dwmac4.h
index c7bff59..dedd406 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4.h
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4.h
@@ -347,7 +347,7 @@ enum power_event {
#define MTL_RX_OVERFLOW_INT BIT(16)
/* Default operating mode of the MAC */
-#define GMAC_CORE_INIT (GMAC_CONFIG_JD | GMAC_CONFIG_PS | GMAC_CONFIG_ACS | \
+#define GMAC_CORE_INIT (GMAC_CONFIG_JD | GMAC_CONFIG_PS | \
GMAC_CONFIG_BE | GMAC_CONFIG_DCRS)
/* To dump the core regs excluding the Address Registers */
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
b/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
index a3af92e..517b1f6 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
@@ -31,13 +31,6 @@ static void dwmac4_core_init(struct mac_device_info *hw,
value |= GMAC_CORE_INIT;
- /* Clear ACS bit because Ethernet switch tagging formats such as
- * Broadcom tags can look like invalid LLC/SNAP packets and cause the
- * hardware to truncate packets on reception.
- */
- if (netdev_uses_dsa(dev))
- value &= ~GMAC_CONFIG_ACS;
-
if (mtu > 1500)
value |= GMAC_CONFIG_2K;
if (mtu > 2000)
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 9a16931..b65e2d1 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -3495,8 +3495,13 @@ static int stmmac_rx(struct stmmac_priv *priv, int
limit, u32 queue)
/* ACS is set; GMAC core strips PAD/FCS for IEEE 802.3
* Type frames (LLC/LLC-SNAP)
+ *
+ * llc_snap is never checked in GMAC >= 4, so this ACS
+ * feature is always disabled and packets need to be
+ * stripped manually.
*/
- if (unlikely(status != llc_snap))
+ if (unlikely(priv->synopsys_id >= DWMAC_CORE_4_00) ||
+ unlikely(status != llc_snap))
frame_len -= ETH_FCS_LEN;
if (netif_msg_rx_status(priv)) {
--
1.7.1
