[PATCH v2 0/4] usb: hub: convert khubd into workqueue

[Petr Mladek <pmladek@suse.cz>]

The workqueue API is well defined and tested. It has many options
that could be used to tune the scheduling. The code is usually
easier and thus more safe. It allows to avoid the extra thread
in most cases. It has has clearly defined behavior vrt. system suspend.

This patchset converts khubd into the workqueue. It saves one thread,
lock, and list.

It  looks huge but the main change is in the first patch. The rest is
simple renaming of functions, comments and documentation.

Changes in v2:

	+ solved potential races:
	  	 + get hub->kref in kick_hub_wq()
		 + call usb_get_dev(hdev) in hub_probe()
		   and 	usb_put_dev(hdev) in hub_release()
		 + INIT_WORK only once in hub_probe()
	 + do not call cancel_work_sync() in hub_disconnect()
	   to keep it fast
	 + rename kick_khubd() to kick_hub_wq() already
	   in the first patch; IMHO, it is cleaner while
	   adding only very few changes
	   
I send all patches again. Especially, 2nd and 3rd patch
needed refresh.

Note that the while cycle in hub_events() was needed when using
the kthread. More events might appear in the list before
the thread is scheduled. This is why I kept the order of patches
as is to do not break bisection.

Thanks a lot Alan Stern for hint and guidance.

The patches can be applied either against Linus' tree or linux-next.


Petr Mladek (4):
  usb: hub: convert khubd into workqueue
  usb: hub: remove obsolete while cycle in hub_event()
  usb: hub: rename usb_kick_khubd() to usb_kick_hub_wq()
  usb: hub: rename khubd to hub_wq in documentation and comments

 Documentation/DocBook/usb.tmpl             |   2 +-
 Documentation/usb/WUSB-Design-overview.txt |   6 +-
 Documentation/usb/hotplug.txt              |   2 +-
 drivers/net/usb/usbnet.c                   |  14 +-
 drivers/usb/README                         |   2 +-
 drivers/usb/core/hcd.c                     |  14 +-
 drivers/usb/core/hub.c                     | 380 +++++++++++++----------------
 drivers/usb/core/hub.h                     |   2 +-
 drivers/usb/core/usb.h                     |   2 +-
 drivers/usb/host/ehci-fsl.c                |   2 +-
 drivers/usb/host/ehci-hcd.c                |   2 +-
 drivers/usb/host/ehci-hub.c                |   8 +-
 drivers/usb/host/fhci-hcd.c                |   6 +-
 drivers/usb/host/fotg210-hcd.c             |   8 +-
 drivers/usb/host/fusbh200-hcd.c            |   8 +-
 drivers/usb/host/isp1760-hcd.c             |   6 +-
 drivers/usb/host/ohci-hcd.c                |   6 +-
 drivers/usb/host/ohci-hub.c                |   4 +-
 drivers/usb/host/ohci-omap.c               |   2 +-
 drivers/usb/host/oxu210hp-hcd.c            |  10 +-
 drivers/usb/host/sl811-hcd.c               |   8 +-
 drivers/usb/host/xhci-hub.c                |   2 +-
 drivers/usb/host/xhci.c                    |   4 +-
 drivers/usb/misc/usbtest.c                 |   2 +-
 drivers/usb/musb/am35x.c                   |   1 +
 drivers/usb/musb/tusb6010.c                |   2 +-
 drivers/usb/phy/phy-fsl-usb.c              |   2 +-
 drivers/usb/phy/phy-isp1301-omap.c         |   2 +-
 drivers/usb/wusbcore/devconnect.c          |   6 +-
 drivers/usb/wusbcore/wa-hc.h               |   2 +-
 sound/usb/midi.c                           |   2 +-
 31 files changed, 240 insertions(+), 279 deletions(-)

-- 
1.8.4