4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Jose Abreu <Jose.Abreu@xxxxxxxxxxxx>
commit 565020aaeebfa7c8b3ec077bee38f4c15acc9905 upstream.
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 <joabreu@xxxxxxxxxxxx>
Cc: David S. Miller <davem@xxxxxxxxxxxxx>
Cc: Joao Pinto <jpinto@xxxxxxxxxxxx>
Cc: Giuseppe Cavallaro <peppe.cavallaro@xxxxxx>
Cc: Alexandre Torgue <alexandre.torgue@xxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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(-)
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4.h
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4.h
@@ -336,7 +336,7 @@ 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 */
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
@@ -30,13 +30,6 @@ static void dwmac4_core_init(struct mac_
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)
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -3415,8 +3415,13 @@ static int stmmac_rx(struct stmmac_priv
/* 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)) {
