From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alexandre Bounine , Matt Porter , Andrew Morton , Linus Torvalds Subject: [ 046/127] rapidio/tsi721: fix bug in MSI interrupt handling Date: Wed, 5 Jun 2013 14:33:33 -0700 Message-Id: <20130605213223.220518960@linuxfoundation.org> In-Reply-To: <20130605213217.966891866@linuxfoundation.org> References: <20130605213217.966891866@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alexandre Bounine 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 Signed-off-by: Greg Kroah-Hartman --- drivers/rapidio/devices/tsi721.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) --- a/drivers/rapidio/devices/tsi721.c +++ b/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; }