net: stmmac: Disable ACS Feature for GMAC >= 4

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: 477286b53f ("stmmac: add GMAC4 core support")
Signed-off-by: Jose Abreu <joabreu@synopsys.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Joao Pinto <jpinto@synopsys.com>
Cc: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jose Abreu 2018-04-18 10:57:55 +01:00 committed by David S. Miller
parent da42bb2713
commit 565020aaee
3 changed files with 7 additions and 9 deletions

View file

@ -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 */

View file

@ -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)

View file

@ -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)) {