On Tue, Feb 7, 2017 at 1:02 AM, Anup Patel <anup.patel@xxxxxxxxxxxx> wrote: > On Tue, Feb 7, 2017 at 1:57 PM, Dan Williams <dan.j.williams@xxxxxxxxx> wrote: >> 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. > > Even if we do capability checks in Linux MD, we still need a way > for DMAENGINE drivers to advertise number of PQ coefficients > handled by the HW. > > I agree capability checks should be done once in Linux MD but I don't > see why this has to be part of BCM-SBA-RAID driver patches. We need > separate patchsets to address limitations of async_tx framework. Right, separate enabling before we pile on new hardware support to a known broken framework.
