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authorDan Williams <dan.j.williams@intel.com>2009-09-08 12:01:49 -0700
committerDan Williams <dan.j.williams@intel.com>2009-09-08 17:30:24 -0700
commit09c8a5b85e5f1e74a19bdd7c85547429d51df1cd (patch)
tree9bb255d9f596ab062996de49032875e8b9253971 /drivers/idle
parentad643f54c8514998333bc6c7b201fda2267496be (diff)
downloadop-kernel-dev-09c8a5b85e5f1e74a19bdd7c85547429d51df1cd.zip
op-kernel-dev-09c8a5b85e5f1e74a19bdd7c85547429d51df1cd.tar.gz
ioat: switch watchdog and reset handler from workqueue to timer
In order to support dynamic resizing of the descriptor ring or polling for a descriptor in the presence of a hung channel the reset handler needs to make progress while in a non-preemptible context. The current workqueue implementation precludes polling channel reset completion under spin_lock(). This conversion also allows us to return to opportunistic cleanup in the ioat2 case as the timer implementation guarantees at least one cleanup after every descriptor is submitted. This means the worst case completion latency becomes the timer frequency (for exceptional circumstances), but with the benefit of avoiding busy waiting when the lock is contended. Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/idle')
-rw-r--r--drivers/idle/i7300_idle.c16
1 files changed, 8 insertions, 8 deletions
diff --git a/drivers/idle/i7300_idle.c b/drivers/idle/i7300_idle.c
index f2ec724..1f20a04 100644
--- a/drivers/idle/i7300_idle.c
+++ b/drivers/idle/i7300_idle.c
@@ -126,9 +126,9 @@ static void i7300_idle_ioat_stop(void)
udelay(10);
sts = readq(ioat_chanbase + IOAT1_CHANSTS_OFFSET) &
- IOAT_CHANSTS_DMA_TRANSFER_STATUS;
+ IOAT_CHANSTS_STATUS;
- if (sts != IOAT_CHANSTS_DMA_TRANSFER_STATUS_ACTIVE)
+ if (sts != IOAT_CHANSTS_ACTIVE)
break;
}
@@ -160,9 +160,9 @@ static int __init i7300_idle_ioat_selftest(u8 *ctl,
udelay(1000);
chan_sts = readq(ioat_chanbase + IOAT1_CHANSTS_OFFSET) &
- IOAT_CHANSTS_DMA_TRANSFER_STATUS;
+ IOAT_CHANSTS_STATUS;
- if (chan_sts != IOAT_CHANSTS_DMA_TRANSFER_STATUS_DONE) {
+ if (chan_sts != IOAT_CHANSTS_DONE) {
/* Not complete, reset the channel */
writeb(IOAT_CHANCMD_RESET,
ioat_chanbase + IOAT1_CHANCMD_OFFSET);
@@ -288,9 +288,9 @@ static void __exit i7300_idle_ioat_exit(void)
ioat_chanbase + IOAT1_CHANCMD_OFFSET);
chan_sts = readq(ioat_chanbase + IOAT1_CHANSTS_OFFSET) &
- IOAT_CHANSTS_DMA_TRANSFER_STATUS;
+ IOAT_CHANSTS_STATUS;
- if (chan_sts != IOAT_CHANSTS_DMA_TRANSFER_STATUS_ACTIVE) {
+ if (chan_sts != IOAT_CHANSTS_ACTIVE) {
writew(0, ioat_chanbase + IOAT_CHANCTRL_OFFSET);
break;
}
@@ -298,14 +298,14 @@ static void __exit i7300_idle_ioat_exit(void)
}
chan_sts = readq(ioat_chanbase + IOAT1_CHANSTS_OFFSET) &
- IOAT_CHANSTS_DMA_TRANSFER_STATUS;
+ IOAT_CHANSTS_STATUS;
/*
* We tried to reset multiple times. If IO A/T channel is still active
* flag an error and return without cleanup. Memory leak is better
* than random corruption in that extreme error situation.
*/
- if (chan_sts == IOAT_CHANSTS_DMA_TRANSFER_STATUS_ACTIVE) {
+ if (chan_sts == IOAT_CHANSTS_ACTIVE) {
printk(KERN_ERR I7300_PRINT "Unable to stop IO A/T channels."
" Not freeing resources\n");
return;
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