target/linux/mediatek/patches-4.4/0095-net-next-mediatek-add-IRQ-locking.patch

   1 From dd08d1ac4cfc86fbea5ee207b9615922ede88ec6 Mon Sep 17 00:00:00 2001
   2 From: John Crispin <john@phrozen.org>
   3 Date: Tue, 17 May 2016 06:01:45 +0200
   4 Subject: [PATCH 095/102] net-next: mediatek: add IRQ locking
   5
   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
  11 disabling IRQs.
  12
  13 Signed-off-by: Sean Wang <keyhaede@gmail.com>
  14 Signed-off-by: John Crispin <john@phrozen.org>
  15 ---
  16  drivers/net/ethernet/mediatek/mtk_eth_soc.c |    7 +++++++
  17  drivers/net/ethernet/mediatek/mtk_eth_soc.h |    1 +
  18  2 files changed, 8 insertions(+)
  19
  20 diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
  21 index 13ee15f..c869064 100644
  22 --- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
  23 +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
  24 @@ -331,18 +331,24 @@ static void mtk_mdio_cleanup(struct mtk_eth *eth)
  25
  26  static inline void mtk_irq_disable(struct mtk_eth *eth, u32 mask)
  27  {
  28 +       unsigned long flags;
  29         u32 val;
  30
  31 +       spin_lock_irqsave(&eth->irq_lock, flags);
  32         val = mtk_r32(eth, MTK_QDMA_INT_MASK);
  33         mtk_w32(eth, val & ~mask, MTK_QDMA_INT_MASK);
  34 +       spin_unlock_irqrestore(&eth->irq_lock, flags);
  35  }
  36
  37  static inline void mtk_irq_enable(struct mtk_eth *eth, u32 mask)
  38  {
  39 +       unsigned long flags;
  40         u32 val;
  41
  42 +       spin_lock_irqsave(&eth->irq_lock, flags);
  43         val = mtk_r32(eth, MTK_QDMA_INT_MASK);
  44         mtk_w32(eth, val | mask, MTK_QDMA_INT_MASK);
  45 +       spin_unlock_irqrestore(&eth->irq_lock, flags);
  46  }
  47
  48  static int mtk_set_mac_address(struct net_device *dev, void *p)
  49 @@ -1771,6 +1777,7 @@ static int mtk_probe(struct platform_device *pdev)
  50                 return -EADDRNOTAVAIL;
  51
  52         spin_lock_init(&eth->page_lock);
  53 +       spin_lock_init(&eth->irq_lock);
  54
  55         eth->ethsys = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
  56                                                       "mediatek,ethsys");
  57 diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.h b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
  58 index a5eb7c6..3159d2a 100644
  59 --- a/drivers/net/ethernet/mediatek/mtk_eth_soc.h
  60 +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
  61 @@ -373,6 +373,7 @@ struct mtk_eth {
  62         void __iomem                    *base;
  63         struct reset_control            *rstc;
  64         spinlock_t                      page_lock;
  65 +       spinlock_t                      irq_lock;
  66         struct net_device               dummy_dev;
  67         struct net_device               *netdev[MTK_MAX_DEVS];
  68         struct mtk_mac                  *mac[MTK_MAX_DEVS];
  69 --
  70 1.7.10.4
  71