[PATCH net-next] ethernet/atheros/alx: sanitize buffer sizing and padding
From: Jarod Wilson
Date: Tue Jan 05 2016 - 18:12:53 EST
This is based on the work done by Przemek Rudy in bug 70761 at
bugzilla.kernel.org, but with some work done to disentagle and clarify
things a bit.
Similar to Przemek's work and other drivers, we're adding a padding of 16
here, but we're also disentangling mtu size calculations from max buffer
size calculations a bit, and adding ETH_HLEN to the value written into
ALX_MTU. Hopefully, with a bit more consistency and clarity, things behave
better here. Sadly, I can only test in my alx-driven E2200, which worked
just fine before this patch.
In comment #58 of bug 70761, Eugene A. Shatokhin reports that this patch
does help considerably for a ROSA Linux user of his with an AR8162 network
adapter when patched into a 4.1.x-based kernel, with several days of
normal operation where wired network previously wasn't usable without
setting MTU to 9000 as a work-around. Other users report less substatial
improvements, but no regressions thus far.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=70761
CC: "Eugene A. Shatokhin" <eugene.shatokhin@xxxxxxxxxx>
CC: Przemek Rudy <prudy1@xxxxx>
CC: Jay Cliburn <jcliburn@xxxxxxxxx>
CC: Chris Snook <chris.snook@xxxxxxxxx>
CC: netdev@xxxxxxxxxxxxxxx
Signed-off-by: Jarod Wilson <jarod@xxxxxxxxxx>
---
drivers/net/ethernet/atheros/alx/hw.c | 10 +++++-----
drivers/net/ethernet/atheros/alx/hw.h | 9 ++++++---
drivers/net/ethernet/atheros/alx/main.c | 7 +++----
3 files changed, 14 insertions(+), 12 deletions(-)
diff --git a/drivers/net/ethernet/atheros/alx/hw.c b/drivers/net/ethernet/atheros/alx/hw.c
index 7712f06..841bc0d 100644
--- a/drivers/net/ethernet/atheros/alx/hw.c
+++ b/drivers/net/ethernet/atheros/alx/hw.c
@@ -958,13 +958,13 @@ void alx_configure_basic(struct alx_hw *hw)
alx_write_mem32(hw, ALX_TINT_TPD_THRSHLD, hw->ith_tpd);
alx_write_mem32(hw, ALX_TINT_TIMER, hw->imt);
- raw_mtu = hw->mtu + ETH_HLEN;
- alx_write_mem32(hw, ALX_MTU, raw_mtu + 8);
- if (raw_mtu > ALX_MTU_JUMBO_TH)
+ raw_mtu = ALX_RAW_MTU(hw->mtu);
+ alx_write_mem32(hw, ALX_MTU, raw_mtu);
+ if (raw_mtu > (ALX_MTU_JUMBO_TH + ETH_FCS_LEN + VLAN_HLEN))
hw->rx_ctrl &= ~ALX_MAC_CTRL_FAST_PAUSE;
- if ((raw_mtu + 8) < ALX_TXQ1_JUMBO_TSO_TH)
- val = (raw_mtu + 8 + 7) >> 3;
+ if ((raw_mtu) < ALX_TXQ1_JUMBO_TSO_TH)
+ val = (raw_mtu + 7) >> 3;
else
val = ALX_TXQ1_JUMBO_TSO_TH >> 3;
alx_write_mem32(hw, ALX_TXQ1, val | ALX_TXQ1_ERRLGPKT_DROP_EN);
diff --git a/drivers/net/ethernet/atheros/alx/hw.h b/drivers/net/ethernet/atheros/alx/hw.h
index 1554880..f289c05 100644
--- a/drivers/net/ethernet/atheros/alx/hw.h
+++ b/drivers/net/ethernet/atheros/alx/hw.h
@@ -37,6 +37,7 @@
#include <linux/types.h>
#include <linux/mdio.h>
#include <linux/pci.h>
+#include <linux/if_vlan.h>
#include "reg.h"
/* Transmit Packet Descriptor, contains 4 32-bit words.
@@ -343,12 +344,14 @@ struct alx_rrd {
ALX_RSS_HASH_TYPE_IPV4_TCP | \
ALX_RSS_HASH_TYPE_IPV6 | \
ALX_RSS_HASH_TYPE_IPV6_TCP)
-#define ALX_DEF_RXBUF_SIZE 1536
+#define ALX_FRAME_PAD 16
+#define ALX_RAW_MTU(_mtu) (_mtu + ETH_HLEN + ETH_FCS_LEN + VLAN_HLEN)
+#define ALX_MAX_FRAME_LEN(_mtu) (ALIGN((ALX_RAW_MTU(_mtu) + ALX_FRAME_PAD), 8))
+#define ALX_DEF_RXBUF_SIZE ALX_MAX_FRAME_LEN(1500)
#define ALX_MAX_JUMBO_PKT_SIZE (9*1024)
#define ALX_MAX_TSO_PKT_SIZE (7*1024)
#define ALX_MAX_FRAME_SIZE ALX_MAX_JUMBO_PKT_SIZE
-#define ALX_MIN_FRAME_SIZE 68
-#define ALX_RAW_MTU(_mtu) (_mtu + ETH_HLEN + ETH_FCS_LEN + VLAN_HLEN)
+#define ALX_MIN_FRAME_SIZE (ETH_ZLEN + ETH_FCS_LEN + VLAN_HLEN)
#define ALX_MAX_RX_QUEUES 8
#define ALX_MAX_TX_QUEUES 4
diff --git a/drivers/net/ethernet/atheros/alx/main.c b/drivers/net/ethernet/atheros/alx/main.c
index d3763bc..55b118e 100644
--- a/drivers/net/ethernet/atheros/alx/main.c
+++ b/drivers/net/ethernet/atheros/alx/main.c
@@ -704,7 +704,7 @@ static int alx_init_sw(struct alx_priv *alx)
hw->smb_timer = 400;
hw->mtu = alx->dev->mtu;
- alx->rxbuf_size = ALIGN(ALX_RAW_MTU(hw->mtu), 8);
+ alx->rxbuf_size = ALX_MAX_FRAME_LEN(hw->mtu);
alx->tx_ringsz = 256;
alx->rx_ringsz = 512;
hw->imt = 200;
@@ -805,7 +805,7 @@ static void alx_reinit(struct alx_priv *alx)
static int alx_change_mtu(struct net_device *netdev, int mtu)
{
struct alx_priv *alx = netdev_priv(netdev);
- int max_frame = mtu + ETH_HLEN + ETH_FCS_LEN + VLAN_HLEN;
+ int max_frame = ALX_MAX_FRAME_LEN(mtu);
if ((max_frame < ALX_MIN_FRAME_SIZE) ||
(max_frame > ALX_MAX_FRAME_SIZE))
@@ -816,8 +816,7 @@ static int alx_change_mtu(struct net_device *netdev, int mtu)
netdev->mtu = mtu;
alx->hw.mtu = mtu;
- alx->rxbuf_size = mtu > ALX_DEF_RXBUF_SIZE ?
- ALIGN(max_frame, 8) : ALX_DEF_RXBUF_SIZE;
+ alx->rxbuf_size = max(max_frame, ALX_DEF_RXBUF_SIZE);
netdev_update_features(netdev);
if (netif_running(netdev))
alx_reinit(alx);
--
1.8.3.1
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