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authorAlexandre Bounine <alexandre.bounine@idt.com>2013-05-24 15:55:17 -0700
committerBen Hutchings <ben@decadent.org.uk>2013-05-30 14:35:06 +0100
commit1619f441963ea57fa1082d046da867acfcd4d099 (patch)
tree66d983ad350fce3ba404b648d6be37fe9c980cc0
parent7cdf9a24694742936fcf78dc6ed8dc31c636141d (diff)
rapidio/tsi721: fix bug in MSI interrupt handling
commit 1ccc819da6fda9bee10ab8b72e9adbb5ad3e4959 upstream. Fix bug in MSI interrupt handling which causes loss of event notifications. Typical indication of lost MSI interrupts are stalled message and doorbell transfers between RapidIO endpoints. To avoid loss of MSI interrupts all interrupts from the device must be disabled on entering the interrupt handler routine and re-enabled when exiting it. Re-enabling device interrupts will trigger new MSI message(s) if Tsi721 registered new events since entering interrupt handler routine. This patch is applicable to kernel versions starting from v3.2. Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com> Cc: Matt Porter <mporter@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
-rw-r--r--drivers/rapidio/devices/tsi721.c11
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/rapidio/devices/tsi721.c b/drivers/rapidio/devices/tsi721.c
index 33471e11a738..23ef16c94ca5 100644
--- a/drivers/rapidio/devices/tsi721.c
+++ b/drivers/rapidio/devices/tsi721.c
@@ -475,6 +475,10 @@ static irqreturn_t tsi721_irqhandler(int irq, void *ptr)
u32 intval;
u32 ch_inte;
+ /* For MSI mode disable all device-level interrupts */
+ if (priv->flags & TSI721_USING_MSI)
+ iowrite32(0, priv->regs + TSI721_DEV_INTE);
+
dev_int = ioread32(priv->regs + TSI721_DEV_INT);
if (!dev_int)
return IRQ_NONE;
@@ -548,6 +552,13 @@ static irqreturn_t tsi721_irqhandler(int irq, void *ptr)
tsi721_pw_handler(mport);
}
+ /* For MSI mode re-enable device-level interrupts */
+ if (priv->flags & TSI721_USING_MSI) {
+ dev_int = TSI721_DEV_INT_SR2PC_CH | TSI721_DEV_INT_SRIO |
+ TSI721_DEV_INT_SMSG_CH | TSI721_DEV_INT_BDMA_CH;
+ iowrite32(dev_int, priv->regs + TSI721_DEV_INTE);
+ }
+
return IRQ_HANDLED;
}