On Tue, 19 Sep 2006, Jiri Kosina wrote:

> With 2.6.18-rc6-mm2 it is possible on my IBM T42p to do suspend/resume 
> cycle only once. The second time, suspend fails with
> 
>       usb_hcd_pci_suspend(): ehci_pci_suspend+0x0/0xd0 [ehci_hcd]() returns 
> -22
>       pci_device_suspend(): usb_hcd_pci_suspend+0x0/0x280() returns -22
>       suspend_device(): pci_device_suspend+0x0/0x70() returns -22
> 
> or, when ehci is unloaded, uhci fails in a similar way:
> 
>       usb_hcd_pci_suspend(): uhci_suspend+0x0/0xf0 [uhci_hcd]() returns -16
>       pci_device_suspend(): usb_hcd_pci_suspend+0x0/0x1c0() returns -16
>       suspend_device(): pci_device_suspend+0x0/0x70() returns -16
> 
> (by the way this looks to me like a mess, that the user could be presented 
> with either -EINVAL or -EBUSY, in case of the same error, depending on the 
> device driver which reports it. I will probably submit a consolidating 
> patch later this evening).
> 
> After some time I figured out that usb_resume_both() is not resuming 
> devices properly - it calls resume_device() only for those devices which 
> are USB_STATE_SUSPENDED (in which case we want to propagate the resume 
> recursively up the device tree), but other cases (most notably 
> USB_STATE_CONFIGURED) stay unhadled.
> 
> This patch fixes my issue, now the suspend/resume can be done arbitrary 
> number of times without any error.
> 
> Signed-off-by: Jiri Kosina <[EMAIL PROTECTED]>
> 
> --- linux-2.6.18-rc6-mm2.orig/drivers/usb/core/driver.c       2006-09-14 
> 16:20:48.000000000 +0200
> +++ linux-2.6.18-rc6-mm2/drivers/usb/core/driver.c    2006-09-19 
> 03:03:12.000000000 +0200
> @@ -1083,6 +1083,8 @@ int usb_resume_both(struct usb_device *u
>                       status = resume_device(udev);
>               if (parent)
>                       mutex_unlock(&parent->pm_mutex);
> +     } else {
> +             status = resume_device(udev);
>       }
>  
>       /* Now the parent won't suspend until we are finished */

Oddly enough, I identified exactly the same problem last week and 
submitted a nearly-identical patch just a few minutes ago.  The problem 
occurs only when CONFIG_USB_SUSPEND isn't set, and it stems from the fact 
that without this addition, the device's dev.power.power_state.event field 
doesn't get set properly during the resume.

Alan Stern


-------------------------------------------------------------------------
Take Surveys. Earn Cash. Influence the Future of IT
Join SourceForge.net's Techsay panel and you'll get the chance to share your
opinions on IT & business topics through brief surveys -- and earn cash
http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV
_______________________________________________
[email protected]
To unsubscribe, use the last form field at:
https://lists.sourceforge.net/lists/listinfo/linux-usb-devel

Reply via email to