On Sat, Feb 1, 2014 at 10:44 AM, Alan Stern <st...@rowland.harvard.edu> wrote:
> On Fri, 31 Jan 2014, Dan Williams wrote:
>
>> Toggling port power currently leads to three unintended disconnect
>> scenarios that are addressed by this rework of port power recovery and
>> usb device resume:
>>
>> 1/ Superspeed devices downgrade to their hispeed connection: fix this by
>> preventing superspeed poweroff until the peer port is suspended.
>> This depends on the ability to identify peer ports (patches 1-4), and
>> then patch 5 implements the policy.
>>
>> 2/ khubd prematurely disconnects ports that are in the process of
>> being resumed or reset. khubd now ignores ports in the
>> pm-runtime-suspended state (patch 9) and holds a lock to synchronize the
>> port
>> status changes of usb_port_{suspend|resume} (patch 11).
>>
>> 3/ Superspeed devices fail to reconnect: Seen during repeated toggles of
>> the port power state. Fixed by forcing a full recovery cycle of the
>> usb_device before allowing the next suspend / khubd run (patch 12).
>> Also, for devices that live lock on reconnect the port runtime resume
>> path now has the capability to force a reset-resume to be a
>> warm-reset-resume (patch 13).
>
> I haven't gone through all this in any detail. But a couple of things
> stand out immediately, matters of style.
>
> Although the USB stack still has plenty of old code with multiline
> comments looking this this:
>
> /* blah blah blah
> * blah blah blah
> */
>
> the accepted style is that all new code should appear like this:
>
> /*
> * blah blah blah
> * blah blah blah
> */
Ah, the eternal debate. No worries.
> Also, the style for indentation througout most of the USB stack is that
> continuation lines are indented by two tab stops beyond the first line
> of the statement. They are not aligned with opening parentheses of
> function calls or anything like that.
Unfortunate that what goes for net/, or drivers/md/ doesn't go for
drivers/usb/... sounds like checkpatch needs subsystem specific style
rules to avoid this thrash.
If it's just the style I'll put those changes on a git branch and
spare the list if you're ok doing a pull... otherwise I'll hold off
until you have a chance to take a closer look.
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