From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andy Shevchenko Subject: [PATCH v3 8/9] dmaengine: dw: return immediately from IRQ when DMA isn't in use Date: Fri, 4 Dec 2015 23:49:24 +0200 Message-ID: <1449265765-9393-9-git-send-email-andriy.shevchenko@linux.intel.com> References: <1449265765-9393-1-git-send-email-andriy.shevchenko@linux.intel.com> Return-path: In-Reply-To: <1449265765-9393-1-git-send-email-andriy.shevchenko@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org To: "Rafael J . Wysocki" , linux-acpi@vger.kernel.org, Vinod Koul , dmaengine@vger.kernel.org, Thomas Gleixner , Greg Kroah-Hartman , Jarkko Nikula , linux-kernel@vger.kernel.org, Mika Westerberg Cc: Andy Shevchenko List-Id: linux-acpi@vger.kernel.org There is no need to bother the hardware when all channels are idle. We have not to get any interrupts. Signed-off-by: Andy Shevchenko --- drivers/dma/dw/core.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c index 7067b6d..8b20930 100644 --- a/drivers/dma/dw/core.c +++ b/drivers/dma/dw/core.c @@ -622,12 +622,17 @@ static void dw_dma_tasklet(unsigned long data) static irqreturn_t dw_dma_interrupt(int irq, void *dev_id) { struct dw_dma *dw = dev_id; - u32 status = dma_readl(dw, STATUS_INT); + u32 status; + /* Check if we have any interrupt from the DMAC which is not in use */ + if (!dw->in_use) + return IRQ_NONE; + + status = dma_readl(dw, STATUS_INT); dev_vdbg(dw->dma.dev, "%s: status=0x%x\n", __func__, status); /* Check if we have any interrupt from the DMAC */ - if (!status || !dw->in_use) + if (!status) return IRQ_NONE; /* -- 2.6.2