Re: [PATCH] ep93xx: Implement double buffering for M2M DMA channels

From: Rafal Prylowski
Date: Tue Apr 17 2012 - 03:15:49 EST


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.

<snip>

> 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
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/