From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752793AbbKZPU7 (ORCPT ); Thu, 26 Nov 2015 10:20:59 -0500 Received: from mga02.intel.com ([134.134.136.20]:53900 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751646AbbKZPTW (ORCPT ); Thu, 26 Nov 2015 10:19:22 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.20,347,1444719600"; d="scan'208";a="847643355" From: Andy Shevchenko 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 Subject: [PATCH v2 6/7] dmaengine: dw: return immediately from IRQ when DMA isn't in use Date: Thu, 26 Nov 2015 17:19:12 +0200 Message-Id: <1448551153-84719-7-git-send-email-andriy.shevchenko@linux.intel.com> X-Mailer: git-send-email 2.6.2 In-Reply-To: <1448551153-84719-1-git-send-email-andriy.shevchenko@linux.intel.com> References: <1448551153-84719-1-git-send-email-andriy.shevchenko@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@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