Hello Felipe On Tue, Nov 25, 2014 at 3:54 PM, Felipe Balbi <balbi@xxxxxx> wrote: > Hi, > > On Tue, Nov 25, 2014 at 02:44:16AM +0100, Ricardo Ribalda Delgado wrote: >> > might be better if you can fix the code, instead. We have a "better" >> > scatter-gather support in the framework itself. >> >> As I understand it, the code was designed to reduce the number of irqs >> when you expect to send X consecutive packages. In that scenario you >> only want an irq at the end. ie, u_ether supports it. It was not >> designed for sg. >> >> The problem is that the driver only allocates one sg descriptor per >> endpoint, without the possibility of chaining the request I dont see > > right, but what I'm is that we don't want the UDC manually allocating SG > lists and moving req->buf to that sg, we want the gadget driver to pass > a properly formatted sg to the UDC. Currently, only UASP implementation > on top of target framework is doing that. Eventually, we should have > more functions passing sgs to the UDC. i understand. What I want to do is remove the use_dma_chaining and then add support for sg. > >> how can this can work. And it does not work on my hw. >> >> If you could confirm what I am saying about the dma_chaining by >> testing it on net2280 then I think we should remote the module >> parameter, because it will only confuse the user and also ofuscates a >> lot the code. > > Unfortunately I don't have net2280 and I keep forgetting if Alan has > net2280 or net2272. It doesnt really matter. Any will do for the test @Alan, could you please give it a try with is use_dma_chaining obsolete=1 > >> > UDC needs to set gadget->sg_supported and a pointer to the sg should be >> > passed in by the gadget driver through usb_request->sg. >> >> I could try to implement "pure" sg on net2282.c , but I will only be >> able to test it on usb338x hardware. If you could test it later I can >> give it a try. >> >> Regards! >> >> -- >> Ricardo Ribalda > > -- > balbi -- Ricardo Ribalda -- 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
