Re: [PATCH] dmaengine: add CSR SiRFprimaII DMAC driver

From: Jassi Brar
Date: Thu Sep 08 2011 - 03:49:08 EST


On Thu, Sep 8, 2011 at 12:06 PM, Barry Song <21cnbao@xxxxxxxxx> wrote:
> 2011/9/8 Jassi Brar <jassisinghbrar@xxxxxxxxx>:
>> According to figures, {xlen > width} is to be set _only_ when a transfer
>> is divided into _exactly_ two chunks separated by gap _exactly_
>> equal to length of the second chunk (an extremely rare case).
>
> Sorry i didn't list related full information in datasheet in my early reply.
> we don't have the case of xlen > dma_width.
Then the dmac driver becomes even simpler.
Accept strictly 'rectangular' requests and reject every other.


>> Anyways, every case can be easily expressed using the generic api
>> I proposed. See 'struct xfer_template' in https://lkml.org/lkml/2011/8/12/128
>
> i think it is the interleaved DMA case and there is a
> inter-chunk-gap(ICG) between every chunk while dma_width > xlen,
> then your new generic API can definitely cover this case.
>
Yup, it does. Thanks for confirming.
--
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/