Hi David,
Greg KH has picked up the alx driver fix for 4.6 stable kernel, and
people are asking about plan for 4.4/4.1 stable kernel in
https://bugzilla.kernel.org/show_bug.cgi?id=70761
Since the fix patch in your "net" git can't be applied to 4.4 and older
kernel as is, so I backport it as follows. Could you help to add it
to your stable queue.
Let me know if I break any netdev+stable patch rule, thanks
- Feng
----
>From 9c9caee22400c7ed3a514b1ee5e017e5e5b6b812 Mon Sep 17 00:00:00 2001
From: Feng Tang <feng.t...@intel.com>
Date: Fri, 24 Jun 2016 15:26:05 +0800
Subject: [PATCH] net: alx: Work around the DMA RX overflow issue
Note: This is a verified backported patch for stable 4.4 kernel, and it
could also be applied to 4.3/4.2/4.1/3.18/3.16
There is a problem with alx devices, that the network link will be
lost in 1-5 minutes after the device is up.
>From debugging without datasheet, we found the error always
happen when the DMA RX address is set to 0x....fc0, which is very
likely to be a HW/silicon problem.
This patch will apply rx skb with 64 bytes longer space, and if the
allocated skb has a 0x...fc0 address, it will use skb_resever(skb, 64)
to advance the address, so that the RX overflow can be avoided.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=70761
Signed-off-by: Feng Tang <feng.t...@intel.com>
Suggested-by: Eric Dumazet <eduma...@google.com>
Tested-by: Ole Lukoie <oleluk...@mail.ru>
---
drivers/net/ethernet/atheros/alx/main.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/atheros/alx/main.c
b/drivers/net/ethernet/atheros/alx/main.c
index c8af3ce..a43d6a8 100644
--- a/drivers/net/ethernet/atheros/alx/main.c
+++ b/drivers/net/ethernet/atheros/alx/main.c
@@ -86,9 +86,14 @@ static int alx_refill_rx_ring(struct alx_priv *alx, gfp_t
gfp)
while (!cur_buf->skb && next != rxq->read_idx) {
struct alx_rfd *rfd = &rxq->rfd[cur];
- skb = __netdev_alloc_skb(alx->dev, alx->rxbuf_size, gfp);
+ skb = __netdev_alloc_skb(alx->dev, alx->rxbuf_size + 64, gfp);
if (!skb)
break;
+
+ /* Workround for the HW RX DMA overflow issue */
+ if (((unsigned long)skb->data & 0xfff) == 0xfc0)
+ skb_reserve(skb, 64);
+
dma = dma_map_single(&alx->hw.pdev->dev,
skb->data, alx->rxbuf_size,
DMA_FROM_DEVICE);
--
2.5.0
>From 9c9caee22400c7ed3a514b1ee5e017e5e5b6b812 Mon Sep 17 00:00:00 2001
From: Feng Tang <feng.t...@intel.com>
Date: Fri, 24 Jun 2016 15:26:05 +0800
Subject: [PATCH] net: alx: Work around the DMA RX overflow issue
Note: This is a verified backported patch for stable 4.4 kernel, and it
could also be applied to 4.3/4.2/4.1/3.18/3.16
There is a problem with alx devices, that the network link will be
lost in 1-5 minutes after the device is up.
>From debugging without datasheet, we found the error always
happen when the DMA RX address is set to 0x....fc0, which is very
likely to be a HW/silicon problem.
This patch will apply rx skb with 64 bytes longer space, and if the
allocated skb has a 0x...fc0 address, it will use skb_resever(skb, 64)
to advance the address, so that the RX overflow can be avoided.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=70761
Signed-off-by: Feng Tang <feng.t...@intel.com>
Suggested-by: Eric Dumazet <eduma...@google.com>
Tested-by: Ole Lukoie <oleluk...@mail.ru>
---
drivers/net/ethernet/atheros/alx/main.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/atheros/alx/main.c b/drivers/net/ethernet/atheros/alx/main.c
index c8af3ce..a43d6a8 100644
--- a/drivers/net/ethernet/atheros/alx/main.c
+++ b/drivers/net/ethernet/atheros/alx/main.c
@@ -86,9 +86,14 @@ static int alx_refill_rx_ring(struct alx_priv *alx, gfp_t gfp)
while (!cur_buf->skb && next != rxq->read_idx) {
struct alx_rfd *rfd = &rxq->rfd[cur];
- skb = __netdev_alloc_skb(alx->dev, alx->rxbuf_size, gfp);
+ skb = __netdev_alloc_skb(alx->dev, alx->rxbuf_size + 64, gfp);
if (!skb)
break;
+
+ /* Workround for the HW RX DMA overflow issue */
+ if (((unsigned long)skb->data & 0xfff) == 0xfc0)
+ skb_reserve(skb, 64);
+
dma = dma_map_single(&alx->hw.pdev->dev,
skb->data, alx->rxbuf_size,
DMA_FROM_DEVICE);
--
2.5.0
