diff mbox series

[v2] net: stmmac: dwmac1000: Disable ACS if enhanced descs are not used

Message ID 20200308092556.23881-1-repk@triplefau.lt
State Accepted
Delegated to: David Miller
Headers show
Series [v2] net: stmmac: dwmac1000: Disable ACS if enhanced descs are not used | expand

Commit Message

Remi Pommarel March 8, 2020, 9:25 a.m. UTC
ACS (auto PAD/FCS stripping) removes FCS off 802.3 packets (LLC) so that
there is no need to manually strip it for such packets. The enhanced DMA
descriptors allow to flag LLC packets so that the receiving callback can
use that to strip FCS manually or not. On the other hand, normal
descriptors do not support that.

Thus in order to not truncate LLC packet ACS should be disabled when
using normal DMA descriptors.

Fixes: 47dd7a540b8a0 ("net: add support for STMicroelectronics Ethernet controllers.")
Cc: stable@vger.kernel.org
Signed-off-by: Remi Pommarel <repk@triplefau.lt>
---
Changes since v1:
  - Use reverse christmas tree like declaration
  - Add Fixes tag
---
 drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

David Miller March 9, 2020, 4:29 a.m. UTC | #1
From: Remi Pommarel <repk@triplefau.lt>
Date: Sun,  8 Mar 2020 10:25:56 +0100

> ACS (auto PAD/FCS stripping) removes FCS off 802.3 packets (LLC) so that
> there is no need to manually strip it for such packets. The enhanced DMA
> descriptors allow to flag LLC packets so that the receiving callback can
> use that to strip FCS manually or not. On the other hand, normal
> descriptors do not support that.
> 
> Thus in order to not truncate LLC packet ACS should be disabled when
> using normal DMA descriptors.
> 
> Fixes: 47dd7a540b8a0 ("net: add support for STMicroelectronics Ethernet controllers.")
> Cc: stable@vger.kernel.org
> Signed-off-by: Remi Pommarel <repk@triplefau.lt>

Please don't CC: stable for networking fixes as per the netdev FAQ.

Applied and queued up for -stable, thank you.
Sasha Levin March 9, 2020, 12:25 p.m. UTC | #2
Hi

[This is an automated email]

This commit has been processed because it contains a "Fixes:" tag
fixing commit: 47dd7a540b8a ("net: add support for STMicroelectronics Ethernet controllers.").

The bot has tested the following trees: v5.5.8, v5.4.24, v4.19.108, v4.14.172, v4.9.215, v4.4.215.

v5.5.8: Build OK!
v5.4.24: Build OK!
v4.19.108: Build OK!
v4.14.172: Build failed! Errors:
    drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c:48:35: error: dereferencing pointer to incomplete type ‘struct stmmac_priv’

v4.9.215: Failed to apply! Possible dependencies:
    270c7759fbbc ("net: stmmac: add set_mac to the stmmac_ops")
    8cad443eacf6 ("net: stmmac: Fix reception of Broadcom switches tags")
    9f93ac8d4085 ("net-next: stmmac: Add dwmac-sun8i")
    d8256121a91a ("stmmac: adding new glue driver dwmac-dwc-qos-eth")

v4.4.215: Failed to apply! Possible dependencies:
    0e80bdc9a72d ("stmmac: first frame prep at the end of xmit routine")
    270c7759fbbc ("net: stmmac: add set_mac to the stmmac_ops")
    293e4365a1ad ("stmmac: change descriptor layout")
    2a6d8e172639 ("stmmac: add last_segment field to dma data")
    477286b53f55 ("stmmac: add GMAC4 core support")
    553e2ab3130e ("stmmac: add length field to dma data")
    753a71090f33 ("stmmac: add descriptors function for GMAC 4.xx")
    8cad443eacf6 ("net: stmmac: Fix reception of Broadcom switches tags")
    be434d5075d6 ("stmmac: optimize tx desc management")
    c1fa3212be55 ("stmmac: merge get_rx_owner into rx_status routine.")
    d0225e7de622 ("stmmac: rework the routines to show the ring status")
    e3ad57c96715 ("stmmac: review RX/TX ring management")


NOTE: The patch will not be queued to stable trees until it is upstream.

How should we proceed with this patch?
diff mbox series

Patch

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c
index d0356fbd1e43..542784300620 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c
@@ -24,6 +24,7 @@ 
 static void dwmac1000_core_init(struct mac_device_info *hw,
 				struct net_device *dev)
 {
+	struct stmmac_priv *priv = netdev_priv(dev);
 	void __iomem *ioaddr = hw->pcsr;
 	u32 value = readl(ioaddr + GMAC_CONTROL);
 	int mtu = dev->mtu;
@@ -35,7 +36,7 @@  static void dwmac1000_core_init(struct mac_device_info *hw,
 	 * Broadcom tags can look like invalid LLC/SNAP packets and cause the
 	 * hardware to truncate packets on reception.
 	 */
-	if (netdev_uses_dsa(dev))
+	if (netdev_uses_dsa(dev) || !priv->plat->enh_desc)
 		value &= ~GMAC_CONTROL_ACS;
 
 	if (mtu > 1500)