On Wed, 20 Jun 2012, Austin Schuh wrote: > > The IAA interrupts aren't getting lost. �Instead we're seeing early > > timer expirations, probably caused by imprecise timer values. �What do > > you have CONFIG_HZ set to > > CONFIG_HZ=100 Yes, that explains it. The timer values would be too imprecise for any CONFIG_HZ value smaller than 200. Okay, never mind the IAA stuff... > Ok. Here's the trace. I might have an extra print or two in there > from some of my other debugging, but it should be pretty clean. ... > [ 430.268189] usb 1-4: usbdev_do_ioctl: SUBMITURB > [ 430.268196] usb 1-4: userurb 00007f1c3881e250, ep2 bulk-out, length 12 > [ 430.268199] data: 0c 00 00 00 01 00 16 91 25 00 00 00 > ........%... > [ 430.268324] ehci_hcd 0000:00:1a.7: IRQ: status c009 cmd 10021 > > $ cat 0000\:00\:1a.7/async > qh/ffff88055e366980 dev7 hs ep2 42002207 40000000 (00008c00 data0 nak4) > ffff880037801240 out len=0 00008c00 urb ffff880522de5c80 That's the smoking gun. There _was_ an interrupt, and the STS_INT bit (the 0x01 bit) in the status register was set. That should have caused ehci_irq to call ehci_work -> scan_async -> qh_completions. qh_completions should have seen that the QTD_STS_ACTIVE bit wasn't set in the qTD token (the 0x80 bit in the low-order byte of the 00008c00 word in the second line of the "async" file). That would tell it the transfer was complete. Here's a patch to print out the values of the qTD tokens. Let's see what it shows when your transfer hangs up. Leave the "IRQ:" message in place. Alan Stern Index: usb-3.4/drivers/usb/host/ehci-q.c =================================================================== --- usb-3.4.orig/drivers/usb/host/ehci-q.c +++ usb-3.4/drivers/usb/host/ehci-q.c @@ -364,6 +364,7 @@ qh_completions (struct ehci_hcd *ehci, s /* hardware copies qtd out of qh overlay */ rmb (); token = hc32_to_cpu(ehci, qtd->hw_token); +ehci_dbg(ehci, "qh %p qtd %p token %x\n", qh, qtd, token); /* always clean up qtds the hc de-activated */ retry_xacterr: -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
