Hi, > On 14-01-2012 0:10, Felipe Balbi wrote: > > >>> CPPI4.1 (Communication Port Programming Interface) is a TI specific > DMA > >>> controller used in multiple TI platform such as AM33x, DA8x, AM35x, > TI81x. > >>> The DMA engine is mainly used by musb controller on above platform. > > >> There are (at least out of tree) platforms using CPPI 4.1 for > Ethernet. > > > if they are out of tree, I'm sorry but we don't care about them. If > they > > are in tree, then that needs to be sorted out on the same patchset. > > I'm not sure if Puma-5 is the only one using CPPI 4.1 for Etherhet, > and not some new platfroms introduced just now like AM33x/TI81x. Currently AM33x/TI81x doesn't use cppi4.1 for Ethernet. > > >>> It would involve changes in existing musb driver also for which > current > >>> plan is to maintain the compatibility of non-CPPI4.1 DMA in musb > driver. > > >> I didn't quite understand this part... > > > how come ? What he's saying is that while moving cppi-dma.c to > > How come we are taling of cppi-dma.c at all? It's CPPI 3.0 driver > having > nothing in common with CPPI 4.1. > > > drivers/dma he will not move all the other dma engines (Inventra, > OMAP, > > TUSB-over-GPMC, etc). > > >>> The task is planned to be spitted into below subtasks. > > >>> (1) Post RFC on the API details, changes envisaged in musb driver > and other > >>> challenges > > >> First of all, I foresee changes in drivers/dma/ to cope with the > >> entity in CPPI 4.1 called the queue manager (there's also buffer > >> manager but it wasn't implemented on DA8xx, so I didn't design any > >> API for it). > > > that's why the kernel is open source, right ? If we need to improve > the > > framework so that it understands other types of DMAs, so be it. > > I just foresee difficulties here. We can discuss more on this when we post design and API flow for review. Regards, Ajay > > WBR, Sergei -- 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
