On Mon, Apr 6, 2009 at 8:54 AM, Atsushi Nemoto <anemo@xxxxxxxxxxxxx> wrote:
> This patch adds support for the integrated DMAC of the TXx9 family.
>
> Signed-off-by: Atsushi Nemoto <anemo@xxxxxxxxxxxxx>
> ---
Not quite "ackable" yet...
> +#ifdef CONFIG_MACH_TX49XX
> +#define TXX9_DMA_MAY_HAVE_64BIT_REGS
> +#define TXX9_DMA_HAVE_CCR_LE
> +#define TXX9_DMA_HAVE_SMPCHN
> +#define TXX9_DMA_HAVE_IRQ_PER_CHAN
> +#endif
> +
> +#ifdef TXX9_DMA_HAVE_SMPCHN
> +#define TXX9_DMA_USE_SIMPLE_CHAIN
> +#endif
> +
There seems to be a lot of ifdef magic in the code based on these
defines. Can we move this magic and some of the pure definitions to
drivers/dma/txx9dmac.h? (See the "#ifdefs are ugly" section of
Documentation/SubmittingPatches)
> +static struct dma_async_tx_descriptor *
> +txx9dmac_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
> + size_t len, unsigned long flags)
[..]
> + if (!first) {
> + first = desc;
> + } else {
> + desc_write_CHAR(dc, prev, desc->txd.phys);
> + dma_sync_single_for_device(chan2parent(&dc->chan),
> + prev->txd.phys, ddev->descsize,
> + DMA_TO_DEVICE);
> + list_add_tail(&desc->desc_node,
> + &first->txd.tx_list);
> + }
Is there a reason to keep f'irst' off of the tx_list? It seems like
you could simplify this logic and get rid of the scary looking
list_splice followed by list_add in txx9dmac_desc_put. It also seems
odd that the descriptors on tx_list are not reachable from the
dc->queue list after a submit... but maybe I am missing a subtle
detail?
Regards,
Dan
