Re: [PATCH v2 2/5] async_tx: Handle DMA devices having support for fewer PQ coefficients

[Dan Williams]

On Tue, Feb 7, 2017 at 12:16 AM, Anup Patel <anup.patel@xxxxxxxxxxxx> wrote:
> The DMAENGINE framework assumes that if PQ offload is supported by a
> DMA device then all 256 PQ coefficients are supported. This assumption
> does not hold anymore because we now have BCM-SBA-RAID offload engine
> which supports PQ offload with limited number of PQ coefficients.
>
> This patch extends async_tx APIs to handle DMA devices with support
> for fewer PQ coefficients.
>
> Signed-off-by: Anup Patel <anup.patel@xxxxxxxxxxxx>
> Reviewed-by: Scott Branden <scott.branden@xxxxxxxxxxxx>

I don't like this approach. Define an interface for md to query the
offload engine once at the beginning of time. We should not be adding
any new extensions to async_tx.