On Thu, 2013-01-31 at 16:42 -0500, Matt Porter wrote: > On Thu, Jan 31, 2013 at 08:58:39PM +0000, Arnd Bergmann wrote: > > On Thursday 31 January 2013, Matt Porter wrote: > > > On Wed, Jan 30, 2013 at 09:32:58AM +0000, Arnd Bergmann wrote: > > > > On Wednesday 30 January 2013, Matt Porter wrote: > > > > > + dma_cap_set(DMA_SLAVE, edma_filter_info.dma_cap); > > > > > + of_dma_controller_register(dev->of_node, > > > > > + of_dma_simple_xlate, > > > > > + &edma_filter_info); > > > > > + } > > > > > > > > How do you actually deal with the problem mentioned by Padma, that > > > > the filter function does not know which edma instance it is looking > > > > at? If you assume that there can only be a single edma instance in > > > > the system, that is probably a limitation that should be documented > > > > somewhere, and ideally the probe() function should check for that. > > > > > > I make an assumption of one edma instance in the system in the case of > > > DT being populated. This is always true right now as the only SoC with > > > two EDMA controllers in existence is Davinci DA850. Until recently, > > > Davinci had no DT support. Given the steady work being done today on DT > > > support for DA850, it'll probably be something needed in 3.10. > > > > > > I will add a comment and check in probe() to capture this assumption > > > and then plan to update separately to support DA850 booting from DT. > > > > Ok, sounds good. Hopefully by then we will already have a nicer > > way to write an xlate function that does not rely on a filter > > function. > > Yes, it would be nice to avoid what Padma had to do. I should have > mentioned also that the second EDMA on DA850 has no DMA events of > immediate use on it anyway. All the in-kernel users use events on the > first controller, except for the second MMC instance. That's only used > for a wl12xx module on the EVM and that driver has no DT support so it > doesn't matter yet in the DT case. Because of this, DA850 can actually > add EDMA DT support immediately (on top of this series) and add DMA > support to the DT support already posted for the Davinci SPI and MMC > client drivers. I haven't followed this whole discussion in details, but please notice that I'm aiming to get DT support for the WiLink modules (wlcore, wl12xx...) for 3.10. ;) -- Cheers, Luca. -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
