On Wed, May 12, 2010 at 12:39 AM, Linus WALLEIJ <linus.walleij@xxxxxxxxxxxxxx> wrote: > [Dan] > >> >> +void dma_set_ambaconfig(struct dma_chan *chan, >> >> + struct amba_dma_channel_config *config) >> > >> > What happens when two primecell dma devices are present on one soc? >> > Can that happen? In that case we'll have conflicting providers of >> > dma_set_ambaconfig(). >> > >> >> ...the ->device_control() method is already approaching an ioctl() >> let's just add the argument parameter to complete the capability, >> i.e.: >> >> int (*device_control)(struct dma_chan *chan, enum dma_ctrl_cmd cmd, >> unsigned long arg); > > So the unsigned long arg is to match an ioctl? Okidoki... > > If it was only for in-kernel use a void* would be preferred > I believe since assuming unsigned long to be == bus width > is ... well, disturbing, since we'll be casting this into > a struct pointer. It's safe to assume that Linux does not run on any architecture where sizeof(unsigned long) < sizeof(void *). > So this should also be used for the AMBA configuration stuff > then, so I have to make first a patch to convert all the > device_control functions and then a patch on top of that to > implement the AMBA call as a device_control() thingie? > > (Should work out...) > > Just a bit of work, so will take some more hours :-) Apologies for not discovering this earlier in the review process, but it gets rid of the last bit of 'specialness' of the Primecell api and I can see it allowing other weird commands to be implemented generically down the road. Just let me know if you want to run any compile tests for you. > I will just have to make a proof-of-concept for the AMBA config > interface for Russell first, then I'll be on the ioctl-like API. Ok, I really appreciate your patience, I'll see what I can do to push this post-rc1 if things turn out that way. Regards, Dan -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
