[PATCH V2 0/8] net: mediatek: make the driver pass stress tests

[PATCH V2 0/8] net: mediatek: make the driver pass stress tests

[John Crispin]

While testing the driver we managed to get the TX path to stall and fail
to recover. When dual MAC support was added to the driver, the whole queue
stop/wake code was not properly adapted. There was also a regression in the
locking of the xmit function. The fact that watchdog_timeo was not set and
that the tx_timeout code failed to properly reset the dma, irq and queue
just made the mess complete.

This series make the driver pass stress testing. With this series applied
the testbed has been running for several days and still has not locked up.
We have a second setup that has a small hack patch applied to randomly stop
irqs and/or one of the queues and successfully manages to recover from these
simulated tx stalls.

John Crispin (8):
  net: mediatek: watchdog_timeo was not set
  net: mediatek: mtk_cal_txd_req() returns bad value
  net: mediatek: remove superfluous reset call
  net: mediatek: fix stop and wakeup of queue
  net: mediatek: fix mtk_pending_work
  net: mediatek: fix TX locking
  net: mediatek: move the pending_work struct to the device generic
    struct
  net: mediatek: do not set the QID field in the TX DMA descriptors

 drivers/net/ethernet/mediatek/mtk_eth_soc.c |  106 ++++++++++++++++-----------
 drivers/net/ethernet/mediatek/mtk_eth_soc.h |    4 +-
 2 files changed, 66 insertions(+), 44 deletions(-)

-- 
1.7.10.4

[PATCH V2 1/8] net: mediatek: watchdog_timeo was not set

[John Crispin]

The original commit failed to set watchdog_timeo. This patch sets
watchdog_timeo to HZ.

Signed-off-by: John Crispin <blogic@openwrt.org>
---
 drivers/net/ethernet/mediatek/mtk_eth_soc.c |    1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index e0b68af..bb10d57 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -1645,6 +1645,7 @@ static int mtk_add_mac(struct mtk_eth *eth, struct device_node *np)
 	mac->hw_stats->reg_offset = id * MTK_STAT_OFFSET;
 
 	SET_NETDEV_DEV(eth->netdev[id], eth->dev);
+	eth->netdev[id]->watchdog_timeo = HZ;
 	eth->netdev[id]->netdev_ops = &mtk_netdev_ops;
 	eth->netdev[id]->base_addr = (unsigned long)eth->base;
 	eth->netdev[id]->vlan_features = MTK_HW_FEATURES &
-- 
1.7.10.4

[PATCH V2 2/8] net: mediatek: mtk_cal_txd_req() returns bad value

[John Crispin]

The code used to also support the PDMA engine, which had 2 packet pointers
per descriptor. Because of this we had to divide the result by 2 and round
it up. This is no longer needed as the code only supports QDMA.

Signed-off-by: John Crispin <blogic-p3rKhJxN3npAfugRpC6u6w@public.gmane.org>
---
 drivers/net/ethernet/mediatek/mtk_eth_soc.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index bb10d57..94cceb8 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -681,7 +681,7 @@ static inline int mtk_cal_txd_req(struct sk_buff *skb)
 		nfrags += skb_shinfo(skb)->nr_frags;
 	}
 
-	return DIV_ROUND_UP(nfrags, 2);
+	return nfrags;
 }
 
 static int mtk_start_xmit(struct sk_buff *skb, struct net_device *dev)
-- 
1.7.10.4

[PATCH V2 3/8] net: mediatek: remove superfluous reset call

[John Crispin]

HW reset is triggered in the mtk_hw_init() function. There is no need to
also reset the core during probe.

Signed-off-by: John Crispin <blogic-p3rKhJxN3npAfugRpC6u6w@public.gmane.org>
---
 drivers/net/ethernet/mediatek/mtk_eth_soc.c |    4 ----
 1 file changed, 4 deletions(-)

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index 94cceb8..a4982e4 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -1679,10 +1679,6 @@ static int mtk_probe(struct platform_device *pdev)
 	struct mtk_eth *eth;
 	int err;
 
-	err = device_reset(&pdev->dev);
-	if (err)
-		return err;
-
 	match = of_match_device(of_mtk_match, &pdev->dev);
 	soc = (struct mtk_soc_data *)match->data;
 
-- 
1.7.10.4

[PATCH V2 4/8] net: mediatek: fix stop and wakeup of queue

[John Crispin]

The driver supports 2 MACs. Both run on the same DMA ring. If we go
above/below the TX rings threshold value, we always need to wake/stop
the queue of both devices. Not doing to can cause TX stalls and packet
drops on one of the devices.

Signed-off-by: John Crispin <blogic-p3rKhJxN3npAfugRpC6u6w@public.gmane.org>
---
 drivers/net/ethernet/mediatek/mtk_eth_soc.c |   37 +++++++++++++++++++--------
 1 file changed, 27 insertions(+), 10 deletions(-)

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index a4982e4..4ebc42e 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -684,6 +684,28 @@ static inline int mtk_cal_txd_req(struct sk_buff *skb)
 	return nfrags;
 }
 
+static void mtk_wake_queue(struct mtk_eth *eth)
+{
+	int i;
+
+	for (i = 0; i < MTK_MAC_COUNT; i++) {
+		if (!eth->netdev[i])
+			continue;
+		netif_wake_queue(eth->netdev[i]);
+	}
+}
+
+static void mtk_stop_queue(struct mtk_eth *eth)
+{
+	int i;
+
+	for (i = 0; i < MTK_MAC_COUNT; i++) {
+		if (!eth->netdev[i])
+			continue;
+		netif_stop_queue(eth->netdev[i]);
+	}
+}
+
 static int mtk_start_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	struct mtk_mac *mac = netdev_priv(dev);
@@ -695,7 +717,7 @@ static int mtk_start_xmit(struct sk_buff *skb, struct net_device *dev)
 
 	tx_num = mtk_cal_txd_req(skb);
 	if (unlikely(atomic_read(&ring->free_count) <= tx_num)) {
-		netif_stop_queue(dev);
+		mtk_stop_queue(eth);
 		netif_err(eth, tx_queued, dev,
 			  "Tx Ring full when queue awake!\n");
 		return NETDEV_TX_BUSY;
@@ -720,10 +742,10 @@ static int mtk_start_xmit(struct sk_buff *skb, struct net_device *dev)
 		goto drop;
 
 	if (unlikely(atomic_read(&ring->free_count) <= ring->thresh)) {
-		netif_stop_queue(dev);
+		mtk_stop_queue(eth);
 		if (unlikely(atomic_read(&ring->free_count) >
 			     ring->thresh))
-			netif_wake_queue(dev);
+			mtk_wake_queue(eth);
 	}
 
 	return NETDEV_TX_OK;
@@ -897,13 +919,8 @@ static int mtk_poll_tx(struct mtk_eth *eth, int budget, bool *tx_again)
 	if (!total)
 		return 0;
 
-	for (i = 0; i < MTK_MAC_COUNT; i++) {
-		if (!eth->netdev[i] ||
-		    unlikely(!netif_queue_stopped(eth->netdev[i])))
-			continue;
-		if (atomic_read(&ring->free_count) > ring->thresh)
-			netif_wake_queue(eth->netdev[i]);
-	}
+	if (atomic_read(&ring->free_count) > ring->thresh)
+		mtk_wake_queue(eth);
 
 	return total;
 }
-- 
1.7.10.4

[PATCH V2 5/8] net: mediatek: fix mtk_pending_work

[John Crispin]

The driver supports 2 MACs. Both run on the same DMA ring. If we hit a TX
timeout we need to stop both netdevs before restarting them again. If we
don't do this, mtk_stop() wont shutdown DMA and the consecutive call to
mtk_open() wont restart DMA and enable IRQs.

Signed-off-by: John Crispin <blogic-p3rKhJxN3npAfugRpC6u6w@public.gmane.org>
---
 drivers/net/ethernet/mediatek/mtk_eth_soc.c |   31 ++++++++++++++++++---------
 1 file changed, 21 insertions(+), 10 deletions(-)

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index 4ebc42e..60b66ab 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -1430,19 +1430,30 @@ static int mtk_do_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 
 static void mtk_pending_work(struct work_struct *work)
 {
-	struct mtk_mac *mac = container_of(work, struct mtk_mac, pending_work);
-	struct mtk_eth *eth = mac->hw;
-	struct net_device *dev = eth->netdev[mac->id];
-	int err;
+	struct mtk_eth *eth = container_of(work, struct mtk_eth, pending_work);
+	int err, i;
+	unsigned long restart = 0;
 
 	rtnl_lock();
-	mtk_stop(dev);
 
-	err = mtk_open(dev);
-	if (err) {
-		netif_alert(eth, ifup, dev,
-			    "Driver up/down cycle failed, closing device.\n");
-		dev_close(dev);
+	/* stop all devices to make sure that dma is properly shut down */
+	for (i = 0; i < MTK_MAC_COUNT; i++) {
+		if (!netif_oper_up(eth->netdev[i]))
+			continue;
+		mtk_stop(eth->netdev[i]);
+		__set_bit(i, &restart);
+	}
+
+	/* restart DMA and enable IRQs */
+	for (i = 0; i < MTK_MAC_COUNT; i++) {
+		if (!test_bit(i, &restart))
+			continue;
+		err = mtk_open(eth->netdev[i]);
+		if (err) {
+			netif_alert(eth, ifup, eth->netdev[i],
+			      "Driver up/down cycle failed, closing device.\n");
+			dev_close(eth->netdev[i]);
+		}
 	}
 	rtnl_unlock();
 }
-- 
1.7.10.4

Re: [PATCH V2 5/8] net: mediatek: fix mtk_pending_work

[kbuild test robot]

[-- Attachment #1: Type: text/plain, Size: 4813 bytes --]

Hi John,

[auto build test ERROR on net-next/master]
[also build test ERROR on v4.6-rc2 next-20160407]
[if your patch is applied to the wrong git tree, please drop us a note to help improving the system]

url:    https://github.com/0day-ci/linux/commits/John-Crispin/net-mediatek-make-the-driver-pass-stress-tests/20160408-033430
config: arm-allyesconfig (attached as .config)
reproduce:
        wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        make.cross ARCH=arm 

Note: the linux-review/John-Crispin/net-mediatek-make-the-driver-pass-stress-tests/20160408-033430 HEAD e648090f60723da77108430208b4b957c481048b builds fine.
      It only hurts bisectibility.

All error/warnings (new ones prefixed by >>):

   In file included from include/linux/list.h:8:0,
                    from include/linux/kobject.h:20,
                    from include/linux/device.h:17,
                    from include/linux/node.h:17,
                    from include/linux/cpu.h:16,
                    from include/linux/of_device.h:4,
                    from drivers/net/ethernet/mediatek/mtk_eth_soc.c:15:
   drivers/net/ethernet/mediatek/mtk_eth_soc.c: In function 'mtk_pending_work':
>> include/linux/kernel.h:824:27: error: 'struct mtk_eth' has no member named 'pending_work'
     const typeof( ((type *)0)->member ) *__mptr = (ptr); \
                              ^
>> drivers/net/ethernet/mediatek/mtk_eth_soc.c:1433:24: note: in expansion of macro 'container_of'
     struct mtk_eth *eth = container_of(work, struct mtk_eth, pending_work);
                           ^
   include/linux/kernel.h:824:48: warning: initialization from incompatible pointer type
     const typeof( ((type *)0)->member ) *__mptr = (ptr); \
                                                   ^
>> drivers/net/ethernet/mediatek/mtk_eth_soc.c:1433:24: note: in expansion of macro 'container_of'
     struct mtk_eth *eth = container_of(work, struct mtk_eth, pending_work);
                           ^
   include/linux/kernel.h:824:48: warning: (near initialization for 'eth')
     const typeof( ((type *)0)->member ) *__mptr = (ptr); \
                                                   ^
>> drivers/net/ethernet/mediatek/mtk_eth_soc.c:1433:24: note: in expansion of macro 'container_of'
     struct mtk_eth *eth = container_of(work, struct mtk_eth, pending_work);
                           ^
   In file included from include/linux/compiler.h:60:0,
                    from include/linux/ioport.h:12,
                    from include/linux/device.h:16,
                    from include/linux/node.h:17,
                    from include/linux/cpu.h:16,
                    from include/linux/of_device.h:4,
                    from drivers/net/ethernet/mediatek/mtk_eth_soc.c:15:
>> include/linux/compiler-gcc.h:158:2: error: 'struct mtk_eth' has no member named 'pending_work'
     __builtin_offsetof(a, b)
     ^
   include/linux/stddef.h:16:32: note: in expansion of macro '__compiler_offsetof'
    #define offsetof(TYPE, MEMBER) __compiler_offsetof(TYPE, MEMBER)
                                   ^
   include/linux/kernel.h:825:29: note: in expansion of macro 'offsetof'
     (type *)( (char *)__mptr - offsetof(type,member) );})
                                ^
>> drivers/net/ethernet/mediatek/mtk_eth_soc.c:1433:24: note: in expansion of macro 'container_of'
     struct mtk_eth *eth = container_of(work, struct mtk_eth, pending_work);
                           ^

vim +824 include/linux/kernel.h

^1da177e Linus Torvalds 2005-04-16  818   * @ptr:	the pointer to the member.
^1da177e Linus Torvalds 2005-04-16  819   * @type:	the type of the container struct this is embedded in.
^1da177e Linus Torvalds 2005-04-16  820   * @member:	the name of the member within the struct.
^1da177e Linus Torvalds 2005-04-16  821   *
^1da177e Linus Torvalds 2005-04-16  822   */
^1da177e Linus Torvalds 2005-04-16  823  #define container_of(ptr, type, member) ({			\
^1da177e Linus Torvalds 2005-04-16 @824  	const typeof( ((type *)0)->member ) *__mptr = (ptr);	\
^1da177e Linus Torvalds 2005-04-16  825  	(type *)( (char *)__mptr - offsetof(type,member) );})
^1da177e Linus Torvalds 2005-04-16  826  
b9d4f426 Arnaud Lacombe 2011-07-25  827  /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */

:::::: The code at line 824 was first introduced by commit
:::::: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Linux-2.6.12-rc2

:::::: TO: Linus Torvalds <torvalds@ppc970.osdl.org>
:::::: CC: Linus Torvalds <torvalds@ppc970.osdl.org>

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

[-- Attachment #2: .config.gz --]
[-- Type: application/octet-stream, Size: 56292 bytes --]

[PATCH V2 6/8] net: mediatek: fix TX locking

[John Crispin]

Inside the TX path there is a lock inside the tx_map function. This is
however too late. The patch moves the lock to the start of the xmit
function right before the free count check of the DMA ring happens.
If we do not do this, the code becomes racy leading to TX stalls and
dropped packets. This happens as there are 2 netdevs running on the
same physical DMA ring.

Signed-off-by: John Crispin <blogic-p3rKhJxN3npAfugRpC6u6w@public.gmane.org>
---
 drivers/net/ethernet/mediatek/mtk_eth_soc.c |   20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index 60b66ab..8434355 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -536,7 +536,6 @@ static int mtk_tx_map(struct sk_buff *skb, struct net_device *dev,
 	struct mtk_eth *eth = mac->hw;
 	struct mtk_tx_dma *itxd, *txd;
 	struct mtk_tx_buf *tx_buf;
-	unsigned long flags;
 	dma_addr_t mapped_addr;
 	unsigned int nr_frags;
 	int i, n_desc = 1;
@@ -568,11 +567,6 @@ static int mtk_tx_map(struct sk_buff *skb, struct net_device *dev,
 	if (unlikely(dma_mapping_error(&dev->dev, mapped_addr)))
 		return -ENOMEM;
 
-	/* normally we can rely on the stack not calling this more than once,
-	 * however we have 2 queues running ont he same ring so we need to lock
-	 * the ring access
-	 */
-	spin_lock_irqsave(&eth->page_lock, flags);
 	WRITE_ONCE(itxd->txd1, mapped_addr);
 	tx_buf->flags |= MTK_TX_FLAGS_SINGLE0;
 	dma_unmap_addr_set(tx_buf, dma_addr0, mapped_addr);
@@ -632,8 +626,6 @@ static int mtk_tx_map(struct sk_buff *skb, struct net_device *dev,
 	WRITE_ONCE(itxd->txd3, (TX_DMA_SWC | TX_DMA_PLEN0(skb_headlen(skb)) |
 				(!nr_frags * TX_DMA_LS0)));
 
-	spin_unlock_irqrestore(&eth->page_lock, flags);
-
 	netdev_sent_queue(dev, skb->len);
 	skb_tx_timestamp(skb);
 
@@ -661,8 +653,6 @@ err_dma:
 		itxd = mtk_qdma_phys_to_virt(ring, itxd->txd2);
 	} while (itxd != txd);
 
-	spin_unlock_irqrestore(&eth->page_lock, flags);
-
 	return -ENOMEM;
 }
 
@@ -712,14 +702,22 @@ static int mtk_start_xmit(struct sk_buff *skb, struct net_device *dev)
 	struct mtk_eth *eth = mac->hw;
 	struct mtk_tx_ring *ring = &eth->tx_ring;
 	struct net_device_stats *stats = &dev->stats;
+	unsigned long flags;
 	bool gso = false;
 	int tx_num;
 
+	/* normally we can rely on the stack not calling this more than once,
+	 * however we have 2 queues running ont he same ring so we need to lock
+	 * the ring access
+	 */
+	spin_lock_irqsave(&eth->page_lock, flags);
+
 	tx_num = mtk_cal_txd_req(skb);
 	if (unlikely(atomic_read(&ring->free_count) <= tx_num)) {
 		mtk_stop_queue(eth);
 		netif_err(eth, tx_queued, dev,
 			  "Tx Ring full when queue awake!\n");
+		spin_unlock_irqrestore(&eth->page_lock, flags);
 		return NETDEV_TX_BUSY;
 	}
 
@@ -747,10 +745,12 @@ static int mtk_start_xmit(struct sk_buff *skb, struct net_device *dev)
 			     ring->thresh))
 			mtk_wake_queue(eth);
 	}
+	spin_unlock_irqrestore(&eth->page_lock, flags);
 
 	return NETDEV_TX_OK;
 
 drop:
+	spin_unlock_irqrestore(&eth->page_lock, flags);
 	stats->tx_dropped++;
 	dev_kfree_skb(skb);
 	return NETDEV_TX_OK;
-- 
1.7.10.4

Re: [PATCH V2 6/8] net: mediatek: fix TX locking

[Sergei Shtylyov]

Hello.

On 04/07/2016 10:26 PM, John Crispin wrote:

> Inside the TX path there is a lock inside the tx_map function. This is
> however too late. The patch moves the lock to the start of the xmit
> function right before the free count check of the DMA ring happens.
> If we do not do this, the code becomes racy leading to TX stalls and
> dropped packets. This happens as there are 2 netdevs running on the
> same physical DMA ring.
>
> Signed-off-by: John Crispin <blogic@openwrt.org>
> ---
>   drivers/net/ethernet/mediatek/mtk_eth_soc.c |   20 ++++++++++----------
>   1 file changed, 10 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
> index 60b66ab..8434355 100644
> --- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
> +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
[...]
> @@ -712,14 +702,22 @@ static int mtk_start_xmit(struct sk_buff *skb, struct net_device *dev)
>   	struct mtk_eth *eth = mac->hw;
>   	struct mtk_tx_ring *ring = &eth->tx_ring;
>   	struct net_device_stats *stats = &dev->stats;
> +	unsigned long flags;
>   	bool gso = false;
>   	int tx_num;
>
> +	/* normally we can rely on the stack not calling this more than once,
> +	 * however we have 2 queues running ont he same ring so we need to lock

    s/ont he/ on the/, perhaps a good chance to fix the comment?

> +	 * the ring access
> +	 */
> +	spin_lock_irqsave(&eth->page_lock, flags);
> +
>   	tx_num = mtk_cal_txd_req(skb);
>   	if (unlikely(atomic_read(&ring->free_count) <= tx_num)) {
>   		mtk_stop_queue(eth);
>   		netif_err(eth, tx_queued, dev,
>   			  "Tx Ring full when queue awake!\n");
> +		spin_unlock_irqrestore(&eth->page_lock, flags);
>   		return NETDEV_TX_BUSY;
>   	}
>
[...]

MBR, Sergei

[PATCH V2 7/8] net: mediatek: move the pending_work struct to the device generic struct

[John Crispin]

The worker always touches both netdevs. It is ethernet core and not MAC
specific. We only need one worker, which belongs into the ethernets core
struct.

Signed-off-by: John Crispin <blogic@openwrt.org>
---
 drivers/net/ethernet/mediatek/mtk_eth_soc.c |   10 ++++------
 drivers/net/ethernet/mediatek/mtk_eth_soc.h |    4 ++--
 2 files changed, 6 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index 8434355..f9f8851 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -1193,7 +1193,7 @@ static void mtk_tx_timeout(struct net_device *dev)
 	eth->netdev[mac->id]->stats.tx_errors++;
 	netif_err(eth, tx_err, dev,
 		  "transmit timed out\n");
-	schedule_work(&mac->pending_work);
+	schedule_work(&eth->pending_work);
 }
 
 static irqreturn_t mtk_handle_irq(int irq, void *_eth)
@@ -1438,7 +1438,7 @@ static void mtk_pending_work(struct work_struct *work)
 
 	/* stop all devices to make sure that dma is properly shut down */
 	for (i = 0; i < MTK_MAC_COUNT; i++) {
-		if (!netif_oper_up(eth->netdev[i]))
+		if (!eth->netdev[i])
 			continue;
 		mtk_stop(eth->netdev[i]);
 		__set_bit(i, &restart);
@@ -1463,15 +1463,13 @@ static int mtk_cleanup(struct mtk_eth *eth)
 	int i;
 
 	for (i = 0; i < MTK_MAC_COUNT; i++) {
-		struct mtk_mac *mac = netdev_priv(eth->netdev[i]);
-
 		if (!eth->netdev[i])
 			continue;
 
 		unregister_netdev(eth->netdev[i]);
 		free_netdev(eth->netdev[i]);
-		cancel_work_sync(&mac->pending_work);
 	}
+	cancel_work_sync(&eth->pending_work);
 
 	return 0;
 }
@@ -1659,7 +1657,6 @@ static int mtk_add_mac(struct mtk_eth *eth, struct device_node *np)
 	mac->id = id;
 	mac->hw = eth;
 	mac->of_node = np;
-	INIT_WORK(&mac->pending_work, mtk_pending_work);
 
 	mac->hw_stats = devm_kzalloc(eth->dev,
 				     sizeof(*mac->hw_stats),
@@ -1761,6 +1758,7 @@ static int mtk_probe(struct platform_device *pdev)
 
 	eth->dev = &pdev->dev;
 	eth->msg_enable = netif_msg_init(mtk_msg_level, MTK_DEFAULT_MSG_ENABLE);
+	INIT_WORK(&eth->pending_work, mtk_pending_work);
 
 	err = mtk_hw_init(eth);
 	if (err)
diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.h b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
index 48a5292..eed626d 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.h
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
@@ -363,6 +363,7 @@ struct mtk_rx_ring {
  * @clk_gp1:		The gmac1 clock
  * @clk_gp2:		The gmac2 clock
  * @mii_bus:		If there is a bus we need to create an instance for it
+ * @pending_work:	The workqueue used to reset the dma ring
  */
 
 struct mtk_eth {
@@ -389,6 +390,7 @@ struct mtk_eth {
 	struct clk			*clk_gp1;
 	struct clk			*clk_gp2;
 	struct mii_bus			*mii_bus;
+	struct work_struct		pending_work;
 };
 
 /* struct mtk_mac -	the structure that holds the info about the MACs of the
@@ -398,7 +400,6 @@ struct mtk_eth {
  * @hw:			Backpointer to our main datastruture
  * @hw_stats:		Packet statistics counter
  * @phy_dev:		The attached PHY if available
- * @pending_work:	The workqueue used to reset the dma ring
  */
 struct mtk_mac {
 	int				id;
@@ -406,7 +407,6 @@ struct mtk_mac {
 	struct mtk_eth			*hw;
 	struct mtk_hw_stats		*hw_stats;
 	struct phy_device		*phy_dev;
-	struct work_struct		pending_work;
 };
 
 /* the struct describing the SoC. these are declared in the soc_xyz.c files */
-- 
1.7.10.4

[PATCH V2 8/8] net: mediatek: do not set the QID field in the TX DMA descriptors

[John Crispin]

The QID field gets set to the mac id. This made the DMA linked list queue
the traffic of each MAC on a different internal queue. However during long
term testing we found that this will cause traffic stalls as the multi
queue setup requires a more complete initialisation which is not part of
the upstream driver yet.

This patch removes the code setting the QID field, resulting in all
traffic ending up in queue 0 which works without any special setup.

Signed-off-by: John Crispin <blogic@openwrt.org>
---
 drivers/net/ethernet/mediatek/mtk_eth_soc.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index f9f8851..8163047 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -603,8 +603,7 @@ static int mtk_tx_map(struct sk_buff *skb, struct net_device *dev,
 			WRITE_ONCE(txd->txd1, mapped_addr);
 			WRITE_ONCE(txd->txd3, (TX_DMA_SWC |
 					       TX_DMA_PLEN0(frag_map_size) |
-					       last_frag * TX_DMA_LS0) |
-					       mac->id);
+					       last_frag * TX_DMA_LS0));
 			WRITE_ONCE(txd->txd4, 0);
 
 			tx_buf->skb = (struct sk_buff *)MTK_DMA_DUMMY_DESC;
-- 
1.7.10.4