On 15-11-21, 11:21, Arnd Bergmann wrote: > On Mon, Nov 15, 2021 at 10:14 AM Laurent Pinchart > <laurent.pinchart@xxxxxxxxxxxxxxxx> wrote: > > On Mon, Nov 15, 2021 at 09:54:00AM +0100, Arnd Bergmann wrote: > > > @@ -1285,11 +1287,13 @@ static int xilinx_dpdma_config(struct dma_chan *dchan, > > > spin_lock_irqsave(&chan->lock, flags); > > > > > > /* > > > - * Abuse the slave_id to indicate that the channel is part of a video > > > - * group. > > > + * Abuse the peripheral_config to indicate that the channel is part > > > > Is it still an abuse, or is this now the right way to pass custom data > > to the DMA engine driver ? > > It doesn't make the driver any more portable, but it's now being > more explicit about it. As far as I can tell, this is the best way > to pass data that cannot be expressed through the regular interfaces > in DT and the dmaengine API. > > Ideally there would be a generic way to pass this flag, but I couldn't > figure out what this is actually doing, or whether there is a better > way. Maybe Vinod has an idea. > > I'll change s/Abuse/Use/ for the moment until I get a definite answer. I would feel this is still not use for the peripheral_config, but lets keep it to get rid of slave_id. Also, I would be better if this was moved to DT as the next cell, don't recall why that was not done/feasible. -- ~Vinod
