1 From 8aa53beda6ad6c8154e4f7b8a7ca9815412fa95a Mon Sep 17 00:00:00 2001
2 From: John Crispin <blogic@openwrt.org>
3 Date: Wed, 20 Apr 2016 16:18:07 +0200
4 Subject: [PATCH 87/91] net-next: mediatek: add IRQ locking
6 The code that enables and disables IRQs is missing proper locking. After
7 adding the IRQ separation patch and routing the putting the RX and TX IRQs
8 on different cores we experienced IRQ stalls. Fix this by adding proper
9 locking. We use a dedicated lock to reduce the latency if the IRQ code.
10 Otherwise it might wait for bottom code to finish before reenabling or
13 Signed-off-by: John Crispin <blogic@openwrt.org>
15 drivers/net/ethernet/mediatek/mtk_eth_soc.c | 7 +++++++
16 drivers/net/ethernet/mediatek/mtk_eth_soc.h | 1 +
17 2 files changed, 8 insertions(+)
19 diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
20 index 679cefd..f821820 100644
21 --- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
22 +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
23 @@ -316,22 +316,28 @@ static void mtk_mdio_cleanup(struct mtk_eth *eth)
25 static inline void mtk_irq_disable(struct mtk_eth *eth, u32 mask)
27 + unsigned long flags;
30 + spin_lock_irqsave(ð->irq_lock, flags);
31 val = mtk_r32(eth, MTK_QDMA_INT_MASK);
32 mtk_w32(eth, val & ~mask, MTK_QDMA_INT_MASK);
34 mtk_r32(eth, MTK_QDMA_INT_MASK);
35 + spin_unlock_irqrestore(ð->irq_lock, flags);
38 static inline void mtk_irq_enable(struct mtk_eth *eth, u32 mask)
40 + unsigned long flags;
43 + spin_lock_irqsave(ð->irq_lock, flags);
44 val = mtk_r32(eth, MTK_QDMA_INT_MASK);
45 mtk_w32(eth, val | mask, MTK_QDMA_INT_MASK);
47 mtk_r32(eth, MTK_QDMA_INT_MASK);
48 + spin_unlock_irqrestore(ð->irq_lock, flags);
51 static int mtk_set_mac_address(struct net_device *dev, void *p)
52 @@ -1750,6 +1756,7 @@ static int mtk_probe(struct platform_device *pdev)
53 return -EADDRNOTAVAIL;
55 spin_lock_init(ð->page_lock);
56 + spin_lock_init(ð->irq_lock);
58 eth->ethsys = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
60 diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.h b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
61 index 57f7e8a..8220275 100644
62 --- a/drivers/net/ethernet/mediatek/mtk_eth_soc.h
63 +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
64 @@ -372,6 +372,7 @@ struct mtk_eth {
66 struct reset_control *rstc;
68 + spinlock_t irq_lock;
69 struct net_device dummy_dev;
70 struct net_device *netdev[MTK_MAX_DEVS];
71 struct mtk_mac *mac[MTK_MAX_DEVS];