On Wednesday, 13 September 2006 20:38, Alan Stern wrote: > On Wed, 13 Sep 2006, Rafael J. Wysocki wrote: > > > Well, I have reproduced it with gregkh-usb-usbcore-remove-usb_suspend_root_hub.patch > > reverted too. > > > > Attached is the output of dmesg from the failing case with USB_DEBUG set. > > It covers two attempts to suspend to disk, the second one being unsuccessful, > > with reloading the ohci_hcd module in between. [This kernel also has your > > other patch to prevent the second suspend from failing applied, but it doesn't > > help.] > > Okay. Your problem, and probably Mattia's too, is something other than > what that recent patch addressed. I can't tell from the dmesg log exactly > what went wrong, but I can tell you where to look. > > In drivers/usb/core/driver.c, resume_device() is not succeeding. That is, > the lines near the end which do > > if (status == 0) > udev->dev.power.power_state.event = PM_EVENT_ON; > > aren't running during the first resume. You can see this in the dmesg > log; lines 1173-1175 say > > usb usb1: resuming > usbdev1.1_ep00: PM: resume from 0, parent usb1 still 1 > hub 1-0:1.0: PM: resume from 0, parent usb1 still 1 > > If power_state.event had gotten set to PM_EVENT_ON then the parent state > would be 0, not 1. This is the source of your problem. During your > second suspend attempt, usb1 didn't get handled correctly because its > state was set wrong. (I suspect the mishandling took place in usbcore > rather than the PM core, but it doesn't matter. The state should not have > been wrong to begin with.) Consequently its parent device 0000:00:13.2 > refused to freeze, which aborted the suspend attempt. > > For the usb1 device, udriver->resume should point to the generic_resume() > routine in drivers/usb/core/generic.c. In fact, this should be true for > every device that driver.c:resume_device() sees. But generic_resume() > simply calls usb_port_resume() in hub.c, and the log doesn't contain any > of the USB debugging messages that usb_port_resume() would produce. So I > can't tell what happened. > > The patch below will add some extra debugging information. We need to > find out why the resume didn't succeed. Oh -- and of course, you should > reinstate all those autosuspend patches. Otherwise this patch won't > apply! OK Attached is a dmesg output from 2.6.18-rc6-mm2 with the patch applied. It covers two consecutive attempts to suspend (the second one obviously failed). Greetings, Rafael -- You never change things by fighting the existing reality. R. Buckminster Fuller
Attachment:
dmesg-debug.log.gz
Description: GNU Zip compressed data
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