Hi Maxime, On Thursday 23 October 2014 15:19:33 Maxime Ripard wrote: > On Thu, Oct 23, 2014 at 12:21:31AM +0300, Laurent Pinchart wrote: > > Hi Maxime, > > > > Thank you for the patch. > > > > On Wednesday 22 October 2014 17:44:12 Maxime Ripard wrote: > > > For the slave caps retrieval to be really useful, most drivers need to > > > implement it. > > > > > > Hence, we need to be slightly more aggressive, and trigger a warning at > > > registration time for drivers that don't fill their caps infos in order > > > to > > > encourage them to implement it. > > > > > > Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx> > > > --- > > > > > > drivers/dma/dmaengine.c | 3 +++ > > > 1 file changed, 3 insertions(+) > > > > > > diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c > > > index 98e9431f85ec..4e18981b16bd 100644 > > > --- a/drivers/dma/dmaengine.c > > > +++ b/drivers/dma/dmaengine.c > > > @@ -827,6 +827,9 @@ int dma_async_device_register(struct dma_device > > > *device) BUG_ON(!device->device_issue_pending); > > > > > > BUG_ON(!device->dev); > > > > > > + WARN(dma_has_cap(DMA_SLAVE, device->cap_mask) && > > > !device->generic_slave_caps, > > > + "this driver doesn't support generic slave capabilities > > > reporting\n"); > > > + > > > > This might be slightly too aggressive. > > I disagree with that. If we want at some point to have the drivers > implement it, we should be aggressive (and note that we don't break > anything, the driver will still work as it used to). I meant too aggressive given the possibility that a driver might need its own implementation if not all channels have the same capability. > > I agree with your previous comment on all DMA engine drivers > > returning the same capabilities for all channels, but it might not > > be true anymore in the future, in which case drivers will need to > > implement a custom slave caps function. We could delay support for > > that to when it's needed though. > > Actually, my next patch (59) is removing such possibility... And you > acked it ;) > > Is it still something we should be concerned about? Maybe not now, we can always add that possibility back in the future if needed. -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
