From: prylowski@metasoft.pl (Rafal Prylowski) Date: Tue, 17 Apr 2012 09:15:39 +0200 Subject: [PATCH] ep93xx: Implement double buffering for M2M DMA channels In-Reply-To: References: <4F683B36.8090101@metasoft.pl> <20120321193836.GC3740@mwesterb-mobl.ger.corp.intel.com> <20120323070446.GC5812@mwesterb-mobl.ger.corp.intel.com> <20120410172853.GA25697@mwesterb-mobl> <4F853053.7040800@metasoft.pl> Message-ID: <4F8D189B.3010100@metasoft.pl> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 2012-04-16 20:59, H Hartley Sweeten wrote: > On Wednesday, April 11, 2012 12:19 AM, Rafal Prylowski wrote: > > Rafal, > > This patch still doesn't work on my ep93xx system. > It appears your patch is causing an interrupt storm on my system. > Could you please apply the following patch on top of double buffering patch? I would like to know the state of dma channel when you get that interrupt storm. Thanks, RP Index: linux-2.6/drivers/dma/ep93xx_dma.c =================================================================== --- linux-2.6.orig/drivers/dma/ep93xx_dma.c +++ linux-2.6/drivers/dma/ep93xx_dma.c @@ -606,6 +606,7 @@ static int m2m_hw_interrupt(struct ep93x */ last = list_first_entry(edmac->active.next, struct ep93xx_dma_desc, node)->txd.cookie; + printk("M2M: %x %s\n", status, last ? "last" : ""); /* * Use M2M DMA Buffer FSM and Control FSM to check current state of