On Thu, May 21, 2009 at 3:38 PM, Dan Williams <dcbw@xxxxxxxxxx> wrote: > 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. Right, you need a real SDIO (vs. SD storage) controller on the PCI bus. However I can confirm that the ThinkPad X61 (and T61) controller does full SDIO and you can plug Libertas SDIO cards into it. The older X-series ThinkPads (I tried the X40 and X41) work great too. >> >> (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 > -- 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
