From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Lindgren Subject: [PATCH 6/7] ARM: OMAP: Dispatch only relevant DMA interrupts Date: Wed, 04 Mar 2009 13:54:55 -0800 Message-ID: <20090304215455.21101.47444.stgit@localhost> References: <20090304214540.21101.72079.stgit@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: Received: from mho-01-bos.mailhop.org ([63.208.196.178]:60970 "EHLO mho-01-bos.mailhop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754812AbZCDVy7 (ORCPT ); Wed, 4 Mar 2009 16:54:59 -0500 In-Reply-To: <20090304214540.21101.72079.stgit@localhost> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: linux-arm-kernel@lists.arm.linux.org.uk Cc: Nishant Kamat , linux-omap@vger.kernel.org, Santosh Shilimkar From: Santosh Shilimkar This fixes the spurious interrupt issue on a DMA channel. In OMAP sDMA, contrast to the SDMA.DMA4_CSRi registers, the SDMA.DMA4_IRQSTATUS_Lj registers are updated regardless of the corresponding bits in the SDMA.DMA4_IRQENABLE_Lj registers. Since there are four sDMA interrupt lines and if more than one line is actively used by two concurrently running sDMA softwares modules,then the spurious interrupt can be observed on the other lines. Fix in this patch will only dispatch the relevant and enabled interrupts on a particular line thus perevting spurious IRQ. Signed-off-by: Santosh Shilimkar Acked-by: Nishant Kamat Signed-off-by: Tony Lindgren --- arch/arm/plat-omap/dma.c | 4 +++- 1 files changed, 3 insertions(+), 1 deletions(-) diff --git a/arch/arm/plat-omap/dma.c b/arch/arm/plat-omap/dma.c index eca43bb..c46e5a4 100644 --- a/arch/arm/plat-omap/dma.c +++ b/arch/arm/plat-omap/dma.c @@ -1901,7 +1901,7 @@ static int omap2_dma_handle_ch(int ch) /* STATUS register count is from 1-32 while our is 0-31 */ static irqreturn_t omap2_dma_irq_handler(int irq, void *dev_id) { - u32 val; + u32 val, enable_reg; int i; val = dma_read(IRQSTATUS_L0); @@ -1910,6 +1910,8 @@ static irqreturn_t omap2_dma_irq_handler(int irq, void *dev_id) printk(KERN_WARNING "Spurious DMA IRQ\n"); return IRQ_HANDLED; } + enable_reg = dma_read(IRQENABLE_L0); + val &= enable_reg; /* Dispatch only relevant interrupts */ for (i = 0; i < dma_lch_count && val != 0; i++) { if (val & 1) omap2_dma_handle_ch(i);