Question about runtime pm status issue

hi Rafael, Alan:
I recently meet a problem that I enable a usb disk's runtime auto autosuspend,
set power/autosuspend_delay_ms to be 100 and make its usage_count to be 0. But after a long time, the disk's runtime status always is active. From my view, the disk's status
should be "suspend" after the usage_count being 0 and delay timeout. If my opinion was
wrong, please corrent me. Thanks.

Quoted 8 lines · Lan Tianyu

hi Rafael, Alan:
I recently meet a problem that I enable a usb disk's runtime auto autosuspend,
set power/autosuspend_delay_ms to be 100 and make its usage_count to be 0. But after a long time, the disk's runtime status always is active. From my view, the disk's status
should be "suspend" after the usage_count being 0 and delay timeout. If my opinion was
wrong, please corrent me. Thanks.

Please try to umount the disk to see if it can be auto suspended.

Thanks,

I have umount the disk and there is no user of the device since its usage_count
become zero.

Quoted 3 lines · Lan Tianyu

I have umount the disk and there is no user of the device since its usage_count
become zero.

Looks runtime PM of usb mass storage works well on my box with 3.7.0-rc3-next-20121029, maybe you can enable trace event on runtime PM to see what happened.

Thanks