ethernet/atheros/alx: sanitize buffer sizing and padding
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.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=70761
CC: "Eugene A. Shatokhin" <eugene.shatokhin@rosalab.ru>
CC: Przemek Rudy <prudy1@o2.pl>
CC: Jay Cliburn <jcliburn@gmail.com>
CC: Chris Snook <chris.snook@gmail.com>
CC: netdev@vger.kernel.org
Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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 @@
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 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 @@
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);