On Thu, 2016-01-07 at 10:40 -0500, Alan Stern wrote: > > I understand there are some requirements on the allocation such that > > large blocks are not always available. But what is the proper way to > > determine the upper limit of the size such that the user can avoid > > generating warnings like this? (Also, the application really wants > to > > be able to allocate large buffers, maybe tune swiotlb=?.) > > It's debatable whether this should have generated a warning. Why > doesn't dma_alloc_coherent() simply fail silently? I suspect many drivers to be unable to deal well with a failure. Having this report makes "my device doesn't work" easier to solve as a bug report. Hence it seems to me that a driver which can handle a failure with a good fallback should indicate this with a flag to the VM layer. Regards Oliver -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
