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authorAlan Stern <stern@rowland.harvard.edu>2007-12-11 16:05:30 -0500
committerGreg Kroah-Hartman <gregkh@suse.de>2008-02-01 14:34:55 -0800
commit07d29b63ef6b39963ab37818653284d861cf55af (patch)
tree10460d9d13ad7284b644181af66ecdbf416cc5ba /drivers
parent2e2eb83ffd1aeb92bf8793eea892b5bc05a993ea (diff)
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USB: EHCI: add separate IAA watchdog timer
This patch (as1028) was mostly written by David Brownell; I made only a few changes (extra log info and a small bug fix -- which might account for why David's version had to be reverted). It adds a new watchdog timer to the ehci-hcd driver to be used exclusively for detecting lost or missing IAA notifications. Previously a shared timer had been used, which may have led to some problems as reported by Christian Hoffmann. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Cc: David Brownell <david-b@pacbell.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/usb/host/ehci-dbg.c4
-rw-r--r--drivers/usb/host/ehci-hcd.c77
-rw-r--r--drivers/usb/host/ehci-hub.c2
-rw-r--r--drivers/usb/host/ehci-pci.c2
-rw-r--r--drivers/usb/host/ehci-q.c6
-rw-r--r--drivers/usb/host/ehci.h22
6 files changed, 75 insertions, 38 deletions
diff --git a/drivers/usb/host/ehci-dbg.c b/drivers/usb/host/ehci-dbg.c
index 39673f8194d..64ebfc5548a 100644
--- a/drivers/usb/host/ehci-dbg.c
+++ b/drivers/usb/host/ehci-dbg.c
@@ -786,9 +786,7 @@ static ssize_t fill_registers_buffer(struct debug_buffer *buf)
}
if (ehci->reclaim) {
- temp = scnprintf (next, size, "reclaim qh %p%s\n",
- ehci->reclaim,
- ehci->reclaim_ready ? " ready" : "");
+ temp = scnprintf(next, size, "reclaim qh %p\n", ehci->reclaim);
size -= temp;
next += temp;
}
diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index 264182654f4..5917c6b7ce3 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -110,7 +110,7 @@ static const char hcd_name [] = "ehci_hcd";
#define EHCI_TUNE_MULT_TT 1
#define EHCI_TUNE_FLS 2 /* (small) 256 frame schedule */
-#define EHCI_IAA_JIFFIES (HZ/100) /* arbitrary; ~10 msec */
+#define EHCI_IAA_MSECS 10 /* arbitrary */
#define EHCI_IO_JIFFIES (HZ/10) /* io watchdog > irq_thresh */
#define EHCI_ASYNC_JIFFIES (HZ/20) /* async idle timeout */
#define EHCI_SHRINK_JIFFIES (HZ/200) /* async qh unlink delay */
@@ -267,6 +267,7 @@ static void ehci_quiesce (struct ehci_hcd *ehci)
/*-------------------------------------------------------------------------*/
+static void end_unlink_async(struct ehci_hcd *ehci);
static void ehci_work(struct ehci_hcd *ehci);
#include "ehci-hub.c"
@@ -276,25 +277,41 @@ static void ehci_work(struct ehci_hcd *ehci);
/*-------------------------------------------------------------------------*/
-static void ehci_watchdog (unsigned long param)
+static void ehci_iaa_watchdog(unsigned long param)
{
struct ehci_hcd *ehci = (struct ehci_hcd *) param;
unsigned long flags;
+ u32 status, cmd;
spin_lock_irqsave (&ehci->lock, flags);
+ WARN_ON(!ehci->reclaim);
- /* lost IAA irqs wedge things badly; seen with a vt8235 */
+ status = ehci_readl(ehci, &ehci->regs->status);
+ cmd = ehci_readl(ehci, &ehci->regs->command);
+ ehci_dbg(ehci, "IAA watchdog: status %x cmd %x\n", status, cmd);
+
+ /* lost IAA irqs wedge things badly; seen first with a vt8235 */
if (ehci->reclaim) {
- u32 status = ehci_readl(ehci, &ehci->regs->status);
if (status & STS_IAA) {
ehci_vdbg (ehci, "lost IAA\n");
COUNT (ehci->stats.lost_iaa);
ehci_writel(ehci, STS_IAA, &ehci->regs->status);
- ehci->reclaim_ready = 1;
}
+ ehci_writel(ehci, cmd & ~CMD_IAAD, &ehci->regs->command);
+ end_unlink_async(ehci);
}
- /* stop async processing after it's idled a bit */
+ spin_unlock_irqrestore(&ehci->lock, flags);
+}
+
+static void ehci_watchdog(unsigned long param)
+{
+ struct ehci_hcd *ehci = (struct ehci_hcd *) param;
+ unsigned long flags;
+
+ spin_lock_irqsave(&ehci->lock, flags);
+
+ /* stop async processing after it's idled a bit */
if (test_bit (TIMER_ASYNC_OFF, &ehci->actions))
start_unlink_async (ehci, ehci->async);
@@ -364,8 +381,6 @@ static void ehci_port_power (struct ehci_hcd *ehci, int is_on)
static void ehci_work (struct ehci_hcd *ehci)
{
timer_action_done (ehci, TIMER_IO_WATCHDOG);
- if (ehci->reclaim_ready)
- end_unlink_async (ehci);
/* another CPU may drop ehci->lock during a schedule scan while
* it reports urb completions. this flag guards against bogus
@@ -400,6 +415,7 @@ static void ehci_stop (struct usb_hcd *hcd)
/* no more interrupts ... */
del_timer_sync (&ehci->watchdog);
+ del_timer_sync(&ehci->iaa_watchdog);
spin_lock_irq(&ehci->lock);
if (HC_IS_RUNNING (hcd->state))
@@ -448,6 +464,10 @@ static int ehci_init(struct usb_hcd *hcd)
ehci->watchdog.function = ehci_watchdog;
ehci->watchdog.data = (unsigned long) ehci;
+ init_timer(&ehci->iaa_watchdog);
+ ehci->iaa_watchdog.function = ehci_iaa_watchdog;
+ ehci->iaa_watchdog.data = (unsigned long) ehci;
+
/*
* hw default: 1K periodic list heads, one per frame.
* periodic_size can shrink by USBCMD update if hcc_params allows.
@@ -464,7 +484,6 @@ static int ehci_init(struct usb_hcd *hcd)
ehci->i_thresh = 2 + HCC_ISOC_THRES(hcc_params);
ehci->reclaim = NULL;
- ehci->reclaim_ready = 0;
ehci->next_uframe = -1;
/*
@@ -655,8 +674,7 @@ static irqreturn_t ehci_irq (struct usb_hcd *hcd)
/* complete the unlinking of some qh [4.15.2.3] */
if (status & STS_IAA) {
COUNT (ehci->stats.reclaim);
- ehci->reclaim_ready = 1;
- bh = 1;
+ end_unlink_async(ehci);
}
/* remote wakeup [4.3.1] */
@@ -762,10 +780,16 @@ static int ehci_urb_enqueue (
static void unlink_async (struct ehci_hcd *ehci, struct ehci_qh *qh)
{
- /* if we need to use IAA and it's busy, defer */
- if (qh->qh_state == QH_STATE_LINKED
- && ehci->reclaim
- && HC_IS_RUNNING (ehci_to_hcd(ehci)->state)) {
+ /* failfast */
+ if (!HC_IS_RUNNING(ehci_to_hcd(ehci)->state))
+ end_unlink_async(ehci);
+
+ /* if it's not linked then there's nothing to do */
+ if (qh->qh_state != QH_STATE_LINKED)
+ ;
+
+ /* defer till later if busy */
+ else if (ehci->reclaim) {
struct ehci_qh *last;
for (last = ehci->reclaim;
@@ -775,12 +799,8 @@ static void unlink_async (struct ehci_hcd *ehci, struct ehci_qh *qh)
qh->qh_state = QH_STATE_UNLINK_WAIT;
last->reclaim = qh;
- /* bypass IAA if the hc can't care */
- } else if (!HC_IS_RUNNING (ehci_to_hcd(ehci)->state) && ehci->reclaim)
- end_unlink_async (ehci);
-
- /* something else might have unlinked the qh by now */
- if (qh->qh_state == QH_STATE_LINKED)
+ /* start IAA cycle */
+ } else
start_unlink_async (ehci, qh);
}
@@ -807,7 +827,19 @@ static int ehci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
qh = (struct ehci_qh *) urb->hcpriv;
if (!qh)
break;
- unlink_async (ehci, qh);
+ switch (qh->qh_state) {
+ case QH_STATE_LINKED:
+ case QH_STATE_COMPLETING:
+ unlink_async(ehci, qh);
+ break;
+ case QH_STATE_UNLINK:
+ case QH_STATE_UNLINK_WAIT:
+ /* already started */
+ break;
+ case QH_STATE_IDLE:
+ WARN_ON(1);
+ break;
+ }
break;
case PIPE_INTERRUPT:
@@ -899,6 +931,7 @@ rescan:
unlink_async (ehci, qh);
/* FALL THROUGH */
case QH_STATE_UNLINK: /* wait for hw to finish? */
+ case QH_STATE_UNLINK_WAIT:
idle_timeout:
spin_unlock_irqrestore (&ehci->lock, flags);
schedule_timeout_uninterruptible(1);
diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c
index a165e0a0961..a249d03a502 100644
--- a/drivers/usb/host/ehci-hub.c
+++ b/drivers/usb/host/ehci-hub.c
@@ -134,7 +134,7 @@ static int ehci_bus_suspend (struct usb_hcd *hcd)
}
ehci->command = ehci_readl(ehci, &ehci->regs->command);
if (ehci->reclaim)
- ehci->reclaim_ready = 1;
+ end_unlink_async(ehci);
ehci_work(ehci);
/* Unlike other USB host controller types, EHCI doesn't have
diff --git a/drivers/usb/host/ehci-pci.c b/drivers/usb/host/ehci-pci.c
index 45e04000028..3ba01664f82 100644
--- a/drivers/usb/host/ehci-pci.c
+++ b/drivers/usb/host/ehci-pci.c
@@ -305,7 +305,7 @@ static int ehci_pci_resume(struct usb_hcd *hcd)
/* emptying the schedule aborts any urbs */
spin_lock_irq(&ehci->lock);
if (ehci->reclaim)
- ehci->reclaim_ready = 1;
+ end_unlink_async(ehci);
ehci_work(ehci);
spin_unlock_irq(&ehci->lock);
diff --git a/drivers/usb/host/ehci-q.c b/drivers/usb/host/ehci-q.c
index b10f39c047e..853e5e6396a 100644
--- a/drivers/usb/host/ehci-q.c
+++ b/drivers/usb/host/ehci-q.c
@@ -973,7 +973,7 @@ static void end_unlink_async (struct ehci_hcd *ehci)
struct ehci_qh *qh = ehci->reclaim;
struct ehci_qh *next;
- timer_action_done (ehci, TIMER_IAA_WATCHDOG);
+ iaa_watchdog_done(ehci);
// qh->hw_next = cpu_to_hc32(qh->qh_dma);
qh->qh_state = QH_STATE_IDLE;
@@ -983,7 +983,6 @@ static void end_unlink_async (struct ehci_hcd *ehci)
/* other unlink(s) may be pending (in QH_STATE_UNLINK_WAIT) */
next = qh->reclaim;
ehci->reclaim = next;
- ehci->reclaim_ready = 0;
qh->reclaim = NULL;
qh_completions (ehci, qh);
@@ -1059,11 +1058,10 @@ static void start_unlink_async (struct ehci_hcd *ehci, struct ehci_qh *qh)
return;
}
- ehci->reclaim_ready = 0;
cmd |= CMD_IAAD;
ehci_writel(ehci, cmd, &ehci->regs->command);
(void)ehci_readl(ehci, &ehci->regs->command);
- timer_action (ehci, TIMER_IAA_WATCHDOG);
+ iaa_watchdog_start(ehci);
}
/*-------------------------------------------------------------------------*/
diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h
index 10e71417c35..eeda4c88eba 100644
--- a/drivers/usb/host/ehci.h
+++ b/drivers/usb/host/ehci.h
@@ -74,7 +74,6 @@ struct ehci_hcd { /* one per controller */
/* async schedule support */
struct ehci_qh *async;
struct ehci_qh *reclaim;
- unsigned reclaim_ready : 1;
unsigned scanning : 1;
/* periodic schedule support */
@@ -105,6 +104,7 @@ struct ehci_hcd { /* one per controller */
struct dma_pool *itd_pool; /* itd per iso urb */
struct dma_pool *sitd_pool; /* sitd per split iso urb */
+ struct timer_list iaa_watchdog;
struct timer_list watchdog;
unsigned long actions;
unsigned stamp;
@@ -148,9 +148,21 @@ static inline struct usb_hcd *ehci_to_hcd (struct ehci_hcd *ehci)
}
+static inline void
+iaa_watchdog_start(struct ehci_hcd *ehci)
+{
+ WARN_ON(timer_pending(&ehci->iaa_watchdog));
+ mod_timer(&ehci->iaa_watchdog,
+ jiffies + msecs_to_jiffies(EHCI_IAA_MSECS));
+}
+
+static inline void iaa_watchdog_done(struct ehci_hcd *ehci)
+{
+ del_timer(&ehci->iaa_watchdog);
+}
+
enum ehci_timer_action {
TIMER_IO_WATCHDOG,
- TIMER_IAA_WATCHDOG,
TIMER_ASYNC_SHRINK,
TIMER_ASYNC_OFF,
};
@@ -168,9 +180,6 @@ timer_action (struct ehci_hcd *ehci, enum ehci_timer_action action)
unsigned long t;
switch (action) {
- case TIMER_IAA_WATCHDOG:
- t = EHCI_IAA_JIFFIES;
- break;
case TIMER_IO_WATCHDOG:
t = EHCI_IO_JIFFIES;
break;
@@ -187,8 +196,7 @@ timer_action (struct ehci_hcd *ehci, enum ehci_timer_action action)
// async queue SHRINK often precedes IAA. while it's ready
// to go OFF neither can matter, and afterwards the IO
// watchdog stops unless there's still periodic traffic.
- if (action != TIMER_IAA_WATCHDOG
- && t > ehci->watchdog.expires
+ if (time_before_eq(t, ehci->watchdog.expires)
&& timer_pending (&ehci->watchdog))
return;
mod_timer (&ehci->watchdog, t);