On 15-05-20, 09:21, Dave Jiang wrote: > > > On 5/14/2020 11:48 PM, Vinod Koul wrote: > > On 13-05-20, 09:35, Dave Jiang wrote: > > > > > > > > > On 5/13/2020 12:30 AM, Peter Ujfalusi wrote: > > > > > > > > > > > > On 12/05/2020 2.47, Dave Jiang wrote: > > > > > The cookie tracking in dmaengine expects all submissions completed in > > > > > order. Some DMA devices like Intel DSA can complete submissions out of > > > > > order, especially if configured with a work queue sharing multiple DMA > > > > > engines. Add a status DMA_OUT_OF_ORDER that tx_status can be returned for > > > > > those DMA devices. The user should use callbacks to track the completion > > > > > rather than the DMA cookie. This would address the issue of dmatest > > > > > complaining that descriptors are "busy" when the cookie count goes > > > > > backwards due to out of order completion. Add DMA_COMPLETION_NO_ORDER > > > > > DMA capability to allow the driver to flag the device's ability to complete > > > > > operations out of order. > > > > > > > > I'm still a bit hesitant around this. > > > > If the DMA only support out of order completion then it is mandatory > > > > that each descriptor must have unique callback parameter in order the > > > > client could know which transfer has been completed. > > > > Maybe we can still use the cookie to indicate that, or leave it to users > > to manage? They can add an id in the callback params? > > > > Using former is easy, but still user needs to keep track... later can be > > possibly more suited here? > > > > Is there anything else I need to do with this patch? Not really atm, but i am going to defer this after merge window. -- ~Vinod
