Re: btusb "firmware request while host is not available" at resume

[Luis R. Rodriguez]

On Tue, Oct 3, 2017 at 5:20 PM, Luis R. Rodriguez <mcgrof@xxxxxxxxxx> wrote:
> the ordering devised currently there is:
>
>   o device driver pm ops called
>   o notifier for suspend issued - *going to suspend*
>   o userspace frozen
>   o filesystem freeze
>
> On the way back up this order is inverted:
>
>   o filesystem freeze
>   o userspace frozen
>   o notifier for suspend issued - *going to suspend*
>   o device driver pm ops called

Fortunately I had it a tad bit wrong, but in a good way. Our ordering
on our way down is:

 o notifier for suspend issued - *going to suspend*
 o userspace frozen
 o filesystem freeze (new, being proposed)
 o device driver pm ops called

Then on our way up:

  o device driver pm ops called
  o filesystem thaw
  o userspace thaw
  o notifier for resume issued - *thawing*

So the driver callbacks get called *later*, so anything called in
notifiers do get a chance to quiesce things properly.

  Luis