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Date: Thu, 29 Dec 2011 16:39:02 +0100
From: Francois Romieu <romieu@...zoreil.com>
To: Bjarke Istrup Pedersen <gurligebis@...too.org>
Cc: David Miller <davem@...emloft.net>, shemminger@...tta.com,
bhutchings@...arflare.com, linux-kernel@...r.kernel.org,
netdev@...r.kernel.org, rl@...lgate.ch
Subject: Re: [PATCH 1/1] via-rhine: Fix hanging with high CPU load on low-end broads.
Bjarke Istrup Pedersen <gurligebis@...too.org> :
> 2011/12/28 David Miller <davem@...emloft.net>:
[...]
> > This "shut off only some interrupts" scheme is just asking for trouble.
>
> I agree, it's an ugly hack :)
>
> Is there some way I can help with this, without having to touch the
> code? (C isn't my strong language, especially not kernel mode code) :)
Feel free to try the extra "new year's eve week end is getting closer"
patch below (against net-next).
You have been warned.
diff --git a/drivers/net/ethernet/via/via-rhine.c b/drivers/net/ethernet/via/via-rhine.c
index 5c4983b..6350a2c 100644
--- a/drivers/net/ethernet/via/via-rhine.c
+++ b/drivers/net/ethernet/via/via-rhine.c
@@ -42,7 +42,8 @@
#define DEBUG
static int debug = 1; /* 1 normal messages, 0 quiet .. 7 verbose. */
-static int max_interrupt_work = 20;
+#define RHINE_MSG_DEFAULT \
+ (NETIF_MSG_INTR)
/* Set the copy breakpoint for the copy-only-tiny-frames scheme.
Setting to > 1518 effectively disables this feature. */
@@ -128,11 +129,9 @@ MODULE_AUTHOR("Donald Becker <becker@...ld.com>");
MODULE_DESCRIPTION("VIA Rhine PCI Fast Ethernet driver");
MODULE_LICENSE("GPL");
-module_param(max_interrupt_work, int, 0);
module_param(debug, int, 0);
module_param(rx_copybreak, int, 0);
module_param(avoid_D3, bool, 0);
-MODULE_PARM_DESC(max_interrupt_work, "VIA Rhine maximum events handled per interrupt");
MODULE_PARM_DESC(debug, "VIA Rhine debug level (0-7)");
MODULE_PARM_DESC(rx_copybreak, "VIA Rhine copy breakpoint for copy-only-tiny-frames");
MODULE_PARM_DESC(avoid_D3, "Avoid power state D3 (work-around for broken BIOSes)");
@@ -351,16 +350,25 @@ static const int mmio_verify_registers[] = {
/* Bits in the interrupt status/mask registers. */
enum intr_status_bits {
- IntrRxDone=0x0001, IntrRxErr=0x0004, IntrRxEmpty=0x0020,
- IntrTxDone=0x0002, IntrTxError=0x0008, IntrTxUnderrun=0x0210,
- IntrPCIErr=0x0040,
- IntrStatsMax=0x0080, IntrRxEarly=0x0100,
- IntrRxOverflow=0x0400, IntrRxDropped=0x0800, IntrRxNoBuf=0x1000,
- IntrTxAborted=0x2000, IntrLinkChange=0x4000,
- IntrRxWakeUp=0x8000,
- IntrNormalSummary=0x0003, IntrAbnormalSummary=0xC260,
- IntrTxDescRace=0x080000, /* mapped from IntrStatus2 */
- IntrTxErrSummary=0x082218,
+ IntrRxDone = 0x0001,
+ IntrTxDone = 0x0002,
+ IntrRxErr = 0x0004,
+ IntrTxError = 0x0008,
+ IntrRxEmpty = 0x0020,
+ IntrPCIErr = 0x0040,
+ IntrStatsMax = 0x0080,
+ IntrRxEarly = 0x0100,
+ IntrTxUnderrun = 0x0210,
+ IntrRxOverflow = 0x0400,
+ IntrRxDropped = 0x0800,
+ IntrRxNoBuf = 0x1000,
+ IntrTxAborted = 0x2000,
+ IntrLinkChange = 0x4000,
+ IntrRxWakeUp = 0x8000,
+ IntrTxDescRace = 0x080000, /* mapped from IntrStatus2 */
+ IntrNormalSummary = IntrRxDone | IntrTxDone,
+ IntrTxErrSummary = IntrTxDescRace | IntrTxAborted | IntrTxError |
+ IntrTxUnderrun,
};
/* Bits in WOLcrSet/WOLcrClr and PwrcsrSet/PwrcsrClr */
@@ -439,8 +447,12 @@ struct rhine_private {
struct net_device *dev;
struct napi_struct napi;
spinlock_t lock;
+ struct mutex task_lock;
+ struct work_struct slow_event_task;
struct work_struct reset_task;
+ u32 msg_enable;
+
/* Frequently used values: keep some adjacent for cache effect. */
u32 quirks;
struct rx_desc *rx_head_desc;
@@ -482,7 +494,6 @@ static netdev_tx_t rhine_start_tx(struct sk_buff *skb,
static irqreturn_t rhine_interrupt(int irq, void *dev_instance);
static void rhine_tx(struct net_device *dev);
static int rhine_rx(struct net_device *dev, int limit);
-static void rhine_error(struct net_device *dev, int intr_status);
static void rhine_set_rx_mode(struct net_device *dev);
static struct net_device_stats *rhine_get_stats(struct net_device *dev);
static int netdev_ioctl(struct net_device *dev, struct ifreq *rq, int cmd);
@@ -497,6 +508,8 @@ static void rhine_set_cam_mask(void __iomem *ioaddr, u32 mask);
static void rhine_set_vlan_cam_mask(void __iomem *ioaddr, u32 mask);
static void rhine_init_cam_filter(struct net_device *dev);
static void rhine_update_vcam(struct net_device *dev);
+static void rhine_slow_event_task(struct work_struct *work);
+static void rhine_restart_tx(struct net_device *dev);
#define RHINE_WAIT_FOR(condition) \
do { \
@@ -508,7 +521,7 @@ do { \
1024 - i, __func__, __LINE__); \
} while (0)
-static inline u32 get_intr_status(struct net_device *dev)
+static u32 get_intr_status(struct net_device *dev)
{
struct rhine_private *rp = netdev_priv(dev);
void __iomem *ioaddr = rp->base;
@@ -521,6 +534,16 @@ static inline u32 get_intr_status(struct net_device *dev)
return intr_status;
}
+static void rhine_ack_event(struct rhine_private *rp, u32 mask)
+{
+ void __iomem *ioaddr = rp->base;
+
+ if (rp->quirks & rqStatusWBRace)
+ iowrite8(mask >> 16, ioaddr + IntrStatus2);
+ iowrite16(mask, ioaddr + IntrStatus);
+ mmiowb();
+}
+
/*
* Get power related registers into sane state.
* Notify user about past WOL event.
@@ -657,23 +680,62 @@ static void rhine_poll(struct net_device *dev)
}
#endif
+#define RHINE_EVENT_NAPI_RX (IntrRxDone | \
+ IntrRxErr | \
+ IntrRxEmpty | \
+ IntrRxOverflow | \
+ IntrRxDropped | \
+ IntrRxNoBuf | \
+ IntrRxWakeUp)
+
+#define RHINE_EVENT_NAPI_TX_ERR (IntrTxError | \
+ IntrTxAborted | \
+ IntrTxUnderrun | \
+ IntrTxDescRace)
+#define RHINE_EVENT_NAPI_TX (IntrTxDone | RHINE_EVENT_NAPI_TX_ERR)
+
+#define RHINE_EVENT_NAPI (RHINE_EVENT_NAPI_RX | RHINE_EVENT_NAPI_TX)
+#define RHINE_EVENT_SLOW (IntrPCIErr | IntrStatsMax | IntrLinkChange)
+#define RHINE_EVENT (RHINE_EVENT_NAPI | RHINE_EVENT_SLOW)
+
static int rhine_napipoll(struct napi_struct *napi, int budget)
{
struct rhine_private *rp = container_of(napi, struct rhine_private, napi);
struct net_device *dev = rp->dev;
void __iomem *ioaddr = rp->base;
- int work_done;
+ u16 enable_mask = RHINE_EVENT & 0xffff;
+ int work_done = 0;
+ u32 status;
+
+ status = get_intr_status(dev);
+ rhine_ack_event(rp, status & ~RHINE_EVENT_SLOW);
+
+ if (status & RHINE_EVENT_NAPI_RX)
+ work_done += rhine_rx(dev, budget);
+
+ if (status & RHINE_EVENT_NAPI_TX) {
+ if (status & RHINE_EVENT_NAPI_TX_ERR) {
+ /* Avoid scavenging before Tx engine turned off */
+ RHINE_WAIT_FOR(!(ioread8(ioaddr + ChipCmd) & CmdTxOn));
+ if (ioread8(ioaddr + ChipCmd) & CmdTxOn)
+ netif_warn(rp, tx_err, dev, "Tx still on\n");
+ }
+
+ rhine_tx(dev);
+
+ if (status & RHINE_EVENT_NAPI_TX_ERR)
+ rhine_restart_tx(dev);
+ }
- work_done = rhine_rx(dev, budget);
+ if (status & RHINE_EVENT_SLOW) {
+ enable_mask &= ~RHINE_EVENT_SLOW;
+ schedule_work(&rp->slow_event_task);
+ }
if (work_done < budget) {
napi_complete(napi);
-
- iowrite16(IntrRxDone | IntrRxErr | IntrRxEmpty| IntrRxOverflow |
- IntrRxDropped | IntrRxNoBuf | IntrTxAborted |
- IntrTxDone | IntrTxError | IntrTxUnderrun |
- IntrPCIErr | IntrStatsMax | IntrLinkChange,
- ioaddr + IntrEnable);
+ iowrite16(enable_mask, ioaddr + IntrEnable);
+ mmiowb();
}
return work_done;
}
@@ -797,6 +859,7 @@ static int __devinit rhine_init_one(struct pci_dev *pdev,
rp->quirks = quirks;
rp->pioaddr = pioaddr;
rp->pdev = pdev;
+ rp->msg_enable = netif_msg_init(-1, RHINE_MSG_DEFAULT);
rc = pci_request_regions(pdev, DRV_NAME);
if (rc)
@@ -856,7 +919,9 @@ static int __devinit rhine_init_one(struct pci_dev *pdev,
dev->irq = pdev->irq;
spin_lock_init(&rp->lock);
+ mutex_init(&rp->task_lock);
INIT_WORK(&rp->reset_task, rhine_reset_task);
+ INIT_WORK(&rp->slow_event_task, rhine_slow_event_task);
rp->mii_if.dev = dev;
rp->mii_if.mdio_read = mdio_read;
@@ -1310,12 +1375,7 @@ static void init_registers(struct net_device *dev)
napi_enable(&rp->napi);
- /* Enable interrupts by setting the interrupt mask. */
- iowrite16(IntrRxDone | IntrRxErr | IntrRxEmpty| IntrRxOverflow |
- IntrRxDropped | IntrRxNoBuf | IntrTxAborted |
- IntrTxDone | IntrTxError | IntrTxUnderrun |
- IntrPCIErr | IntrStatsMax | IntrLinkChange,
- ioaddr + IntrEnable);
+ iowrite16(RHINE_EVENT & 0xffff, ioaddr + IntrEnable);
iowrite16(CmdStart | CmdTxOn | CmdRxOn | (Cmd1NoTxPoll << 8),
ioaddr + ChipCmd);
@@ -1434,8 +1494,7 @@ static void rhine_reset_task(struct work_struct *work)
reset_task);
struct net_device *dev = rp->dev;
- /* protect against concurrent rx interrupts */
- disable_irq(rp->pdev->irq);
+ mutex_lock(&rp->task_lock);
napi_disable(&rp->napi);
@@ -1452,7 +1511,8 @@ static void rhine_reset_task(struct work_struct *work)
init_registers(dev);
spin_unlock_bh(&rp->lock);
- enable_irq(rp->pdev->irq);
+
+ mutex_unlock(&rp->task_lock);
dev->trans_start = jiffies; /* prevent tx timeout */
dev->stats.tx_errors++;
@@ -1565,63 +1625,26 @@ static irqreturn_t rhine_interrupt(int irq, void *dev_instance)
{
struct net_device *dev = dev_instance;
struct rhine_private *rp = netdev_priv(dev);
- void __iomem *ioaddr = rp->base;
- u32 intr_status;
- int boguscnt = max_interrupt_work;
+ u32 status;
int handled = 0;
- while ((intr_status = get_intr_status(dev))) {
- handled = 1;
+ status = get_intr_status(dev);
- /* Acknowledge all of the current interrupt sources ASAP. */
- if (intr_status & IntrTxDescRace)
- iowrite8(0x08, ioaddr + IntrStatus2);
- iowrite16(intr_status & 0xffff, ioaddr + IntrStatus);
- IOSYNC;
-
- if (debug > 4)
- netdev_dbg(dev, "Interrupt, status %08x\n",
- intr_status);
-
- if (intr_status & (IntrRxDone | IntrRxErr | IntrRxDropped |
- IntrRxWakeUp | IntrRxEmpty | IntrRxNoBuf)) {
- iowrite16(IntrTxAborted |
- IntrTxDone | IntrTxError | IntrTxUnderrun |
- IntrPCIErr | IntrStatsMax | IntrLinkChange,
- ioaddr + IntrEnable);
-
- napi_schedule(&rp->napi);
- }
+ netif_dbg(rp, intr, dev, "Interrupt, status %08x\n", status);
- if (intr_status & (IntrTxErrSummary | IntrTxDone)) {
- if (intr_status & IntrTxErrSummary) {
- /* Avoid scavenging before Tx engine turned off */
- RHINE_WAIT_FOR(!(ioread8(ioaddr+ChipCmd) & CmdTxOn));
- if (debug > 2 &&
- ioread8(ioaddr+ChipCmd) & CmdTxOn)
- netdev_warn(dev,
- "%s: Tx engine still on\n",
- __func__);
- }
- rhine_tx(dev);
- }
+ if (status & RHINE_EVENT) {
+ handled = 1;
- /* Abnormal error summary/uncommon events handlers. */
- if (intr_status & (IntrPCIErr | IntrLinkChange |
- IntrStatsMax | IntrTxError | IntrTxAborted |
- IntrTxUnderrun | IntrTxDescRace))
- rhine_error(dev, intr_status);
+ iowrite16(0x0000, rp->base + IntrEnable);
+ mmiowb();
+ napi_schedule(&rp->napi);
+ }
- if (--boguscnt < 0) {
- netdev_warn(dev, "Too much work at interrupt, status=%#08x\n",
- intr_status);
- break;
- }
+ if (status & ~(IntrLinkChange | IntrStatsMax | RHINE_EVENT_NAPI)) {
+ netif_err(rp, intr, dev, "Something Wicked happened! %08x\n",
+ status);
}
- if (debug > 3)
- netdev_dbg(dev, "exiting interrupt, status=%08x\n",
- ioread16(ioaddr + IntrStatus));
return IRQ_RETVAL(handled);
}
@@ -1632,8 +1655,6 @@ static void rhine_tx(struct net_device *dev)
struct rhine_private *rp = netdev_priv(dev);
int txstatus = 0, entry = rp->dirty_tx % TX_RING_SIZE;
- spin_lock(&rp->lock);
-
/* find and cleanup dirty tx descriptors */
while (rp->dirty_tx != rp->cur_tx) {
txstatus = le32_to_cpu(rp->tx_ring[entry].tx_status);
@@ -1687,8 +1708,6 @@ static void rhine_tx(struct net_device *dev)
}
if ((rp->cur_tx - rp->dirty_tx) < TX_QUEUE_LEN - 4)
netif_wake_queue(dev);
-
- spin_unlock(&rp->lock);
}
/**
@@ -1852,7 +1871,8 @@ static inline void clear_tally_counters(void __iomem *ioaddr)
ioread16(ioaddr + RxMissed);
}
-static void rhine_restart_tx(struct net_device *dev) {
+static void rhine_restart_tx(struct net_device *dev)
+{
struct rhine_private *rp = netdev_priv(dev);
void __iomem *ioaddr = rp->base;
int entry = rp->dirty_tx % TX_RING_SIZE;
@@ -1880,8 +1900,7 @@ static void rhine_restart_tx(struct net_device *dev) {
iowrite8(ioread8(ioaddr + ChipCmd1) | Cmd1TxDemand,
ioaddr + ChipCmd1);
IOSYNC;
- }
- else {
+ } else {
/* This should never happen */
if (debug > 1)
netdev_warn(dev, "%s() Another error occurred %08x\n",
@@ -1890,15 +1909,25 @@ static void rhine_restart_tx(struct net_device *dev) {
}
-static void rhine_error(struct net_device *dev, int intr_status)
+static void rhine_slow_event_task(struct work_struct *work)
{
- struct rhine_private *rp = netdev_priv(dev);
+ struct rhine_private *rp =
+ container_of(work, struct rhine_private, slow_event_task);
+ struct net_device *dev = rp->dev;
void __iomem *ioaddr = rp->base;
+ u32 intr_status;
- spin_lock(&rp->lock);
+ if (!netif_running(dev))
+ return;
+
+ mutex_lock(&rp->task_lock);
+
+ intr_status = get_intr_status(dev);
+ rhine_ack_event(rp, intr_status & RHINE_EVENT_SLOW);
if (intr_status & IntrLinkChange)
rhine_check_media(dev, 0);
+
if (intr_status & IntrStatsMax) {
dev->stats.rx_crc_errors += ioread16(ioaddr + RxCRCErrs);
dev->stats.rx_missed_errors += ioread16(ioaddr + RxMissed);
@@ -1930,19 +1959,15 @@ static void rhine_error(struct net_device *dev, int intr_status)
netdev_info(dev, "Unspecified error. Tx threshold now %02x\n",
rp->tx_thresh);
}
- if (intr_status & (IntrTxAborted | IntrTxUnderrun | IntrTxDescRace |
- IntrTxError))
- rhine_restart_tx(dev);
- if (intr_status & ~(IntrLinkChange | IntrStatsMax | IntrTxUnderrun |
- IntrTxError | IntrTxAborted | IntrNormalSummary |
- IntrTxDescRace)) {
- if (debug > 1)
- netdev_err(dev, "Something Wicked happened! %08x\n",
- intr_status);
- }
+ napi_disable(&rp->napi);
+ iowrite16(0x0000, ioaddr + IntrEnable);
+ mmiowb();
+ /* Slow and safe. Consider __napi_schedule as a replacement ? */
+ napi_enable(&rp->napi);
+ napi_schedule(&rp->napi);
- spin_unlock(&rp->lock);
+ mutex_unlock(&rp->task_lock);
}
static struct net_device_stats *rhine_get_stats(struct net_device *dev)
@@ -2133,6 +2158,7 @@ static int rhine_close(struct net_device *dev)
void __iomem *ioaddr = rp->base;
napi_disable(&rp->napi);
+ cancel_work_sync(&rp->slow_event_task);
cancel_work_sync(&rp->reset_task);
netif_stop_queue(dev);
--
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