Re: [PATCH] [FIX] dmaengine: virt-dma: Free descriptor after callback

[Russell King - ARM Linux]

On Thu, Apr 17, 2014 at 07:56:50PM -0500, Joel Fernandes wrote:
> Free the vd (virt descriptor) after the callback is called.  In EDMA driver
> atleast which uses virt-dma, we make use of the desc during the callback and if
> its dangerously freed before the callback is called. I also noticed this in
> omap-dma dmaengine driver.

You've missed the vital bit of information: why do you make use of the
descriptor afterwards?  You shouldn't.  omap-dma doesn't either.

Once clients submit their request to DMA engine, they must not hold any
kind of reference to the descriptor other than the cookie.

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