Hi, On Tue, Jun 14, 2011 at 05:52:23PM +0800, Aaron Wu wrote: > On Tue, Jun 14, 2011 at 5:39 PM, Felipe Balbi <balbi@xxxxxx> wrote: > > Hi, > > > > On Tue, Jun 14, 2011 at 05:34:09PM +0800, Aaron Wu wrote: > >> Since the wifi card we are using is of the USB interface. We tried on > >> two diffrent USB controllers, looks like the ISP1362 works OK and > >> problems happens only on MUSB controller. For both USB controllers we > >> are using the same kernel version and USB wifi card. > > > > Yeah, USB host has quite some performance issues to be fixed. To start > > with, it uses only DMA Mode0, which is bound to packet boundaries. BTW, > > which embedded platform are you using ? Which SoC ? > > > > Hi balbi, > Thanks for the quick reply. Our concern is the priority capability, > current problems is, the network data packge should have been > prioritized in the IPV4 stack itself, by IP_TOS option as mentioned, > we are just curious why the priority looks like to have something to > do with the USB controller, I mean by experiment the prioritization > works well on some USB controllers like that on a X86 PC and ISP1362, > but does not work on MUSB. > > We are using PIO mode on Blackfin. Performance is not our concern at > this moment, actually the MUSB has better throughput performance than > the ISP1362, but the prioritization works on 1362. On the 1362 > controller, the second iperf session(high priority) always take up a > large bandwidth while the other two low priority session get only a > little in the test as expected. On MUSB, we see no priority for the > second session, it drops greatly as if it has the same low priority as > the first and third session. Well, I can't answer that question, specially since it's on Blackfin. Maybe Mike can help -- balbi
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