Hi, The Linux OHCI driver doesn't keep the timing requirements for the USB Reset in the function hc_reset. At the end of the function hcReset the Host Controller is set to state UsbReset:
writel (ohci->hc_control, &ohci->regs->control); The OpenHCI documentation says that UsbReset state must be maintained for the minimum time specified in the USB Specification for the assertion of reset on USB, which is 10ms as far as i remember. Unfortunately hc_reset function inserts no pause after writing to hcControl. I meassured that sometimes the UsbReset state is left less than 50 microseconds after writing a 0 to hcControl. This leads to problems with the Netsilicon NS9750 OHCI, which requires that the UsbReset state is not left for 1ms after writing to hcControl (even if hcControl already was 0 before writting). An additional delay of 10 ms after setting the state to reset helps. Jochen ------------------------------------------------------- SF.Net email is sponsored by Shop4tech.com-Lowest price on Blank Media 100pk Sonic DVD-R 4x for only $29 -100pk Sonic DVD+R for only $33 Save 50% off Retail on Ink & Toner - Free Shipping and Free Gift. http://www.shop4tech.com/z/Inkjet_Cartridges/9_108_r285 _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
