On Thu 3 Jan 2008 12:04, Richard D pondered: > Does all USB Host controller hardware have the ability to disable PING?
I think they do. (or at least should)... http://www.intel.com/technology/usb/download/ehci-r10.pdf ================== 4.11 Ping Control (page 88) USB 2.0 defines an addition to the protocol for high-speed devices called Ping. Ping is required for all USB 2.0 High-speed bulk and control endpoints. Ping is not allowed for a split-transaction stream. This extension to the protocol eliminates the bad side-effects of Naking OUT endpoints. The Status field has a Ping State bit, which the host controller uses to determine the next actual PID it will use in the next transaction to the endpoint (see Table 3-16). Table 4–12 illustrates the state transition table for the host controller's responsibility for maintaining the PING protocol. Refer to Chapter 8 in the USB Specification Revision 2.0 for detailed description on the Ping protocol. =============== I think the musb is just missing the PING/OUT State table, as described in table 4-12. I think this is controlled in the ehci driver with: host/ehci.h:#define QTD_STS_PING (1 << 0) /* issue PING? */ -Robin -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
