On Thu, 2009-05-21 at 08:00 +0800, Dongas wrote: > 2009/5/21 Dan Williams <dcbw@xxxxxxxxxx>: > > On Wed, 2009-05-20 at 22:48 +0800, Dongas wrote: > >> 2009/5/20 John W. Linville <linville@xxxxxxxxxxxxx>: > >> > On Wed, May 20, 2009 at 01:48:32AM +0800, Dongas wrote: > >> > > >> >> Why the bandwidth is not changed when bit rate is changed to 11Mb/s? > >> >> Any thing wrong? > >> > > >> > More errors at higher bit rate, resulting in more retries? Just a > >> > thought... > >> > > >> Is there a quick way to verify this possible reason? I'm using Libertas driver. > >> > >> BTW, my sdio host driver is using polling mode to handle SDIO IRQ. > >> Could this be the cause of such poor performance? > > > > Definitely. With libertas, the largest class of issues by *far* that > > we've seen are controller related. I seem to recall that I've pulled > > about 6Mbps through the card using a normal Ricoh controller from a > > Fujitsu laptop. I can recheck that. > > AFAIK, most old laptop ,including my x61, doesn't support SDIO in HW. > So did Ricoh controller you tested use polling mode to handle SDIO IRQ? > Which clock of controller and which bit rate did you test? Actually, most of the older machines *can* do SDIO, those made from about 2006 - 2009. These days a lot of the SD "controllers" are actually USB-based mass-storage converters and cannot do SDIO, they are essentially 10-in-1 cardreaders. What is the 'lspci' output for your Thinkpad? If the controller isn't in 'lspci' but is in 'lsusb', then it's quite unlikely to work because of the above reason, I think. Dan > >> (However I just can't believe the performance is so poor ,only around > >> 1.1Mbps, with polling mode of SDIO IRQ) > > > > What specific kernel version are you using? There have been some > > latency fixes in recent kernels, but would be good to know just to make > > sure. > > I'm using kenrel 2.6.25. > > Thanks > > Regards > Dongas -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
