Re: [linux-usb-devel] [PATCH] Make sleep/wakeup work with USB on powerbooks

On Wednesday 16 March 2005 9:36 pm, Paul Mackerras wrote:

I am currently using this patch on my powerbook to fix the problems
that USB was causing with sleep and wakeup.  Basically one of the USB
controllers was getting a spurious wakeup immediately when put it
into the suspend state.  This would cause the resume routine to be run
after we had turned off the device, causing a machine check.

Do you know yet why the spurious wakeup happened?  As I recall from
earlier discussions, that was indeed the root cause of the problem,
although there were a few other oddnesses that needed handling too.
But without the spurious wakeup, they'd have been quite rare.

Also we had some races where we would turn off the clock to the apple
OHCI cell(s) and then try to access them.  With this patch, sleep and
wakeup are quite reliable.  The patch is against 2.6.11.

Thanks, I'll have a more detailed look soon.  Most of it looks fine,
except for the stuff related to this:

Thing is, that change would also prevent us from getting rid of
the root hub timer for OHCI.   IRQ on connect status change is
not specific to USB_SUSPEND.

- Dave