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Diffstat (limited to 'results/scraper/launchpad-without-comments/1550743')
| -rw-r--r-- | results/scraper/launchpad-without-comments/1550743 | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/results/scraper/launchpad-without-comments/1550743 b/results/scraper/launchpad-without-comments/1550743 new file mode 100644 index 000000000..d665a0598 --- /dev/null +++ b/results/scraper/launchpad-without-comments/1550743 @@ -0,0 +1,26 @@ +connect low speed host devices to qemu ehci does not work + +$ qemu-system-i386 -hda my_x86.img -device ich9-usb-ehci1,id=ehci -device usb-host,vendorid=0x045e,productid=0x071d -serial stdio +qemu-system-i386: Warning: speed mismatch trying to attach usb device "Microsoft? 2.4GHz Transceiver V" ( speed) to bus "ehci.0", port "1" (high speed) +qemu-system-i386: Warning: speed mismatch trying to attach usb device "Microsoft? 2.4GHz Transceiver V" ( speed) to bus "ehci.0", port "1" (high speed) +qemu-system-i386: Warning: speed mismatch trying to attach usb device "Microsoft? 2.4GHz Transceiver V" ( speed) to bus "ehci.0", port "1" (high speed) + +Which is obviously wrong. The ehci specification states: + +Low-speed device, release ownership of port <= Table 2-16. + +Table 2-6: + +Number of Companion Controller (N_CC). This field indicates the number of +companion controllers associated with this USB 2.0 host controller. +A zero in this field indicates there are no companion host controllers. Port-ownership +hand-off is not supported. Only high-speed devices are supported on the host controller +root ports. +A value larger than zero in this field indicates there are companion USB 1.1 host +controller(s). Port-ownership hand-offs are supported. High, Full- and Low-speed +devices are supported on the host controller root ports. + +Which is not longer true, as for example skylake and baytrail offers a dual usb stack of ehci and xhci. In that case, EHCI handles the low speed device as well. + +brgds, +Bert \ No newline at end of file |