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* dma_alloc_coherent fails
@ 2007-06-01 16:46 Maximus
  2007-06-01 21:31 ` Russell King
  0 siblings, 1 reply; 2+ messages in thread
From: Maximus @ 2007-06-01 16:46 UTC (permalink / raw)
  To: linux-kernel

Hi,
Am using a linux 2.6.19 kernel for arm. the dma_alloc_coherent
function call in the kernel for 38400 bytes fails.


Has anyone faced this problem before?.


What could be make dma_alloc_coherent to success sometimes and fail sometimes?.

Regards,
John

^ permalink raw reply	[flat|nested] 2+ messages in thread

* Re: dma_alloc_coherent fails
  2007-06-01 16:46 dma_alloc_coherent fails Maximus
@ 2007-06-01 21:31 ` Russell King
  0 siblings, 0 replies; 2+ messages in thread
From: Russell King @ 2007-06-01 21:31 UTC (permalink / raw)
  To: Maximus; +Cc: linux-kernel

On Fri, Jun 01, 2007 at 10:16:41PM +0530, Maximus wrote:
> Hi,
> Am using a linux 2.6.19 kernel for arm. the dma_alloc_coherent
> function call in the kernel for 38400 bytes fails.
> 
> Has anyone faced this problem before?.
> 
> What could be make dma_alloc_coherent to success sometimes and fail 
> sometimes?.

Memory fragmentation.  Large allocations (> 1 page) are always unreliable.

-- 
Russell King
 Linux kernel    2.6 ARM Linux   - http://www.arm.linux.org.uk/
 maintainer of:

^ permalink raw reply	[flat|nested] 2+ messages in thread

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