On Sun, 22 Jun 2014, pedro wrote: > Hi Alan, > > What happens if you attach the full-speed device to a high-speed hub > and plug that hub into the MUSB? > > > That's a very interesting test i will definitely do. Unfortunately, even > if that solves the problem, we could not use that on our production > boards because we cannot change the design, we are very advanced and > nearly approaching the production phase. We have no chance of changing > any hardware, it should be a software solution. > > I'm also very interested in any opinions about my assumptions because I > really don't know if I'm misunderstanding something and the problem > could be on any other place. > > Basically that assumptions were that we are sending too small packets > (64B) which combines with the interrupt latencies and the degraded > performance of MUSB as it has more work done in software than an EHCI > interface. So for reaching the required 0.5MB/s by reducing the time > spent on the OMAP micro (which i find difficult) or by increasing the > packet size, having to use the Isochronous interface with a risk of > packet losing. I don't know much about the details of the MUSB driver. Your assumption seems reasonable, though. By the way, what size are your transfer requests? > Thanks :) You're welcome. Alan Stern -- 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
