From: Alexandre Bounine <alexandre.bounine@xxxxxxx>
Subject: rapidio/tsi721: fix bug in MSI interrupt handling
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@xxxxxxx>
Cc: Matt Porter <mporter@xxxxxxxxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/rapidio/devices/tsi721.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff -puN drivers/rapidio/devices/tsi721.c~rapidio-tsi721-fix-bug-in-msi-interrupt-handling drivers/rapidio/devices/tsi721.c
--- a/drivers/rapidio/devices/tsi721.c~rapidio-tsi721-fix-bug-in-msi-interrupt-handling
+++ a/drivers/rapidio/devices/tsi721.c
@@ -471,6 +471,10 @@ static irqreturn_t tsi721_irqhandler(int
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;
@@ -560,6 +564,14 @@ static irqreturn_t tsi721_irqhandler(int
}
}
#endif
+
+ /* 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;
}
_
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