From 13bbf8c9ea7e22f1ddeb73d0e2e3876ae59b036d 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 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 Cc: Matt Porter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings Cc: Qiang Huang Signed-off-by: Greg Kroah-Hartman --- drivers/rapidio/devices/tsi721.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/rapidio/devices/tsi721.c b/drivers/rapidio/devices/tsi721.c index 33471e1..23ef16c 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; } -- 2.7.4