Hello, all,
We found this on a PowerPC embedded platform using an FPGA-based USB
host controller. The Linux kernel is 2.6.29.
When disconnect the device during an interrupt transfer, we found that
periodic schedule is disabled, but quickly enabled again. It is later
disabled again. The bogus enable happens in ehci_urb_dequeue():
/* reschedule QH iff another request is queued */
if (!list_empty (&qh->qtd_list)
&& HC_IS_RUNNING (hcd->state)) {
printk(KERN_INFO "qh_schedule in urb_dequeue %x\n",
hcd->state);
rc = qh_schedule(ehci, qh);
The qh_schedule() then calls qh_link_periodic(), which calls
enable_periodic().
It is unclear how qh->qtd_list should be updated properly for the
disconnect, although ep->urb_list is cleared.
Is this a bug?
Thanks,
Julie.
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