From 1ccc819da6fda9bee10ab8b72e9adbb5ad3e4959 Mon Sep 17 00:00:00 2001 From: Alexandre Bounine Date: Fri, 24 May 2013 15:55:17 -0700 Subject: [PATCH] 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 Cc: Matt Porter Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/rapidio/devices/tsi721.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/drivers/rapidio/devices/tsi721.c b/drivers/rapidio/devices/tsi721.c index 6faba406b6e9..a8b2c23a7ef4 100644 --- a/drivers/rapidio/devices/tsi721.c +++ b/drivers/rapidio/devices/tsi721.c @@ -471,6 +471,10 @@ 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; @@ -560,6 +564,14 @@ static irqreturn_t tsi721_irqhandler(int irq, void *ptr) } } #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; }