All of lore.kernel.org
 help / color / mirror / Atom feed
From: John Crispin <john@phrozen.org>
To: "David S. Miller" <davem@davemloft.net>
Cc: nbd@nbd.name, netdev@vger.kernel.org,
	linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org,
	John Crispin <john@phrozen.org>
Subject: [PATCH 3/4] net-next: mediatek: add IRQ locking
Date: Thu,  5 May 2016 11:27:42 +0200	[thread overview]
Message-ID: <1462440463-52076-4-git-send-email-john@phrozen.org> (raw)
In-Reply-To: <1462440463-52076-1-git-send-email-john@phrozen.org>

The code that enables and disables IRQs is missing proper locking. After
adding the IRQ separation patch and routing the putting the RX and TX IRQs
on different cores we experienced IRQ stalls. Fix this by adding proper
locking. We use a dedicated lock to reduce the latency if the IRQ code.
Otherwise it might wait for bottom code to finish before reenabling or
disabling IRQs.

Signed-off-by: John Crispin <john@phrozen.org>
---
 drivers/net/ethernet/mediatek/mtk_eth_soc.c |    7 +++++++
 drivers/net/ethernet/mediatek/mtk_eth_soc.h |    1 +
 2 files changed, 8 insertions(+)

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index 4322585..3d84309 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -316,18 +316,24 @@ static void mtk_mdio_cleanup(struct mtk_eth *eth)
 
 static inline void mtk_irq_disable(struct mtk_eth *eth, u32 mask)
 {
+	unsigned long flags;
 	u32 val;
 
+	spin_lock_irqsave(&eth->irq_lock, flags);
 	val = mtk_r32(eth, MTK_QDMA_INT_MASK);
 	mtk_w32(eth, val & ~mask, MTK_QDMA_INT_MASK);
+	spin_unlock_irqrestore(&eth->irq_lock, flags);
 }
 
 static inline void mtk_irq_enable(struct mtk_eth *eth, u32 mask)
 {
+	unsigned long flags;
 	u32 val;
 
+	spin_lock_irqsave(&eth->irq_lock, flags);
 	val = mtk_r32(eth, MTK_QDMA_INT_MASK);
 	mtk_w32(eth, val | mask, MTK_QDMA_INT_MASK);
+	spin_unlock_irqrestore(&eth->irq_lock, flags);
 }
 
 static int mtk_set_mac_address(struct net_device *dev, void *p)
@@ -1755,6 +1761,7 @@ static int mtk_probe(struct platform_device *pdev)
 		return PTR_ERR(eth->base);
 
 	spin_lock_init(&eth->page_lock);
+	spin_lock_init(&eth->irq_lock);
 
 	eth->ethsys = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
 						      "mediatek,ethsys");
diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.h b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
index a5eb7c6..3159d2a 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.h
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
@@ -373,6 +373,7 @@ struct mtk_eth {
 	void __iomem			*base;
 	struct reset_control		*rstc;
 	spinlock_t			page_lock;
+	spinlock_t			irq_lock;
 	struct net_device		dummy_dev;
 	struct net_device		*netdev[MTK_MAX_DEVS];
 	struct mtk_mac			*mac[MTK_MAX_DEVS];
-- 
1.7.10.4

WARNING: multiple messages have this Message-ID (diff)
From: John Crispin <john-Pj+rj9U5foFAfugRpC6u6w@public.gmane.org>
To: "David S. Miller" <davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>
Cc: netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	John Crispin <john-Pj+rj9U5foFAfugRpC6u6w@public.gmane.org>,
	linux-mediatek-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	nbd-Vt+b4OUoWG0@public.gmane.org
Subject: [PATCH 3/4] net-next: mediatek: add IRQ locking
Date: Thu,  5 May 2016 11:27:42 +0200	[thread overview]
Message-ID: <1462440463-52076-4-git-send-email-john@phrozen.org> (raw)
In-Reply-To: <1462440463-52076-1-git-send-email-john-Pj+rj9U5foFAfugRpC6u6w@public.gmane.org>

The code that enables and disables IRQs is missing proper locking. After
adding the IRQ separation patch and routing the putting the RX and TX IRQs
on different cores we experienced IRQ stalls. Fix this by adding proper
locking. We use a dedicated lock to reduce the latency if the IRQ code.
Otherwise it might wait for bottom code to finish before reenabling or
disabling IRQs.

Signed-off-by: John Crispin <john-Pj+rj9U5foFAfugRpC6u6w@public.gmane.org>
---
 drivers/net/ethernet/mediatek/mtk_eth_soc.c |    7 +++++++
 drivers/net/ethernet/mediatek/mtk_eth_soc.h |    1 +
 2 files changed, 8 insertions(+)

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index 4322585..3d84309 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -316,18 +316,24 @@ static void mtk_mdio_cleanup(struct mtk_eth *eth)
 
 static inline void mtk_irq_disable(struct mtk_eth *eth, u32 mask)
 {
+	unsigned long flags;
 	u32 val;
 
+	spin_lock_irqsave(&eth->irq_lock, flags);
 	val = mtk_r32(eth, MTK_QDMA_INT_MASK);
 	mtk_w32(eth, val & ~mask, MTK_QDMA_INT_MASK);
+	spin_unlock_irqrestore(&eth->irq_lock, flags);
 }
 
 static inline void mtk_irq_enable(struct mtk_eth *eth, u32 mask)
 {
+	unsigned long flags;
 	u32 val;
 
+	spin_lock_irqsave(&eth->irq_lock, flags);
 	val = mtk_r32(eth, MTK_QDMA_INT_MASK);
 	mtk_w32(eth, val | mask, MTK_QDMA_INT_MASK);
+	spin_unlock_irqrestore(&eth->irq_lock, flags);
 }
 
 static int mtk_set_mac_address(struct net_device *dev, void *p)
@@ -1755,6 +1761,7 @@ static int mtk_probe(struct platform_device *pdev)
 		return PTR_ERR(eth->base);
 
 	spin_lock_init(&eth->page_lock);
+	spin_lock_init(&eth->irq_lock);
 
 	eth->ethsys = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
 						      "mediatek,ethsys");
diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.h b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
index a5eb7c6..3159d2a 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.h
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
@@ -373,6 +373,7 @@ struct mtk_eth {
 	void __iomem			*base;
 	struct reset_control		*rstc;
 	spinlock_t			page_lock;
+	spinlock_t			irq_lock;
 	struct net_device		dummy_dev;
 	struct net_device		*netdev[MTK_MAX_DEVS];
 	struct mtk_mac			*mac[MTK_MAX_DEVS];
-- 
1.7.10.4

  parent reply	other threads:[~2016-05-05  9:28 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-05-05  9:27 [PATCH 0/4] net-next: mediatek: implement IRQ grouping John Crispin
2016-05-05  9:27 ` John Crispin
2016-05-05  9:27 ` [PATCH 1/4] net-next: mediatek: remove superfluous register reads John Crispin
2016-05-05  9:27 ` [PATCH 2/4] net-next: mediatek: don't use intermediate variables to store IRQ masks John Crispin
2016-05-05  9:27   ` John Crispin
2016-05-05  9:27 ` John Crispin [this message]
2016-05-05  9:27   ` [PATCH 3/4] net-next: mediatek: add IRQ locking John Crispin
2016-05-05  9:27 ` [PATCH 4/4] net-next: mediatek: add support for IRQ grouping John Crispin
2016-06-15 14:58 [PATCH 0/4] net-next: mediatek: IRQ cleanups, fixes and grouping John Crispin
2016-06-15 14:58 ` [PATCH 3/4] net-next: mediatek: add IRQ locking John Crispin

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1462440463-52076-4-git-send-email-john@phrozen.org \
    --to=john@phrozen.org \
    --cc=davem@davemloft.net \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mediatek@lists.infradead.org \
    --cc=nbd@nbd.name \
    --cc=netdev@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.