Re: [RFC PATCH] scatterlist: Initialize the dma_address field withinvalid dma address

From: David Miller
Date: Thu Dec 09 2010 - 14:59:43 EST


From: Nicolas Ferre <nicolas.ferre@xxxxxxxxx>
Date: Thu, 9 Dec 2010 14:15:14 +0100

> Initialize the the dma_address field so that it will be possible to test
> its value while using scatterlists. This field will be compatible with
> testing by dma_mapping_error().
>
> Signed-off-by: Nicolas Ferre <nicolas.ferre@xxxxxxxxx>

Please don't do this, it's unjustified and it's going to kill performance.
Even if it were a good change, you should have used the invalid DMA
address definition defined by various architectures instead of a constant.

You should be aware of whether entries in a scatterlist have been setup
by your code path.
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