On Tue, Nov 25, 2014 at 4:32 PM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > On Tue, 25 Nov 2014, Ricardo Ribalda Delgado wrote: > >> 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 > > Give what a try? What exactly would you like me to do? Hello Alan Could you test if the parameter dma_chaining works on your board with the current kernel? #on the target modprobe net2280 use_dma_chaining=1 #(it it is already loaded, rmmod) dd if=/dev/zero of=/tmp/mem bs=256M count=1 modprobe g_mass_storage file=/tmp/mem #on the host #Check if /dev/sdX has apperared dd if=/dev/sdX of=/dev/null Thanks! > > Alan Stern > -- 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
