This code implements the setting of devices offline during the removal
phase.

This patch makes us hold the host reference count a little bit longer in
the /proc interface code.  We were releasing it too early before.

  speedtouch: reject outgoing packets earlier when the firmware is not loaded.

  speedtouch: allocate send urbs in udsl_usb_probe rather than in udsl_usb_data_init.
  Since this diminishes udsl_usb_data_init down to almost nothing, roll it into the one
  place it was used.  Get rid of the semaphore Oliver put it - it is no longer needed.


 speedtouch.c |   86 ++++++++++++++++++++++++++---------------------------------
 1 files changed, 38 insertions(+), 48 deletions(-)

  speedtouch: change data_started to firmware_loaded, which is what it actually
  means, plus some minor related changes.

  speedtouch: a pile of cosmetic changes to make me feel happier (no code changes).

  speedtouch: wait for receive urb completion handlers to finish after calling
  usb_unlink_urb.

  speedtouch: more robust handling of receive urb failure: retry failed urbs whenever
  a new connection is opened.  This should work well with pppd's persist option.

Rediffed version of the original patch - no sk_buff on the stack this time.

  speedtouch: recycle the receive urb's buffer.  Currently, every time a receive urb
    completes, its old buffer is thrown away and replaced with a new one.  This patch
    performs the minor changes needed to reuse the old buffer.

  speedtouch: move all processing of receive urbs to udsl_atm_processqueue.  This has
  several advantages, as will be seen in the next few patches.  The most important is
  that it makes it easy to reuse of the urb's buffer (right now a new buffer is
  allocated every time the urb completes).  By the way, this patch is much smaller than
  it looks: most of the bulk is due to indentation changes.

This patch prints the vendor + product ids of the scanner after it has
been successfully detected.

Also the annoying error message about "Scanner device is already open"
was downgraded to a dbg. Scanning for devices while one scanner device
was open produced several 100 error messages in syslog.

This patch changes the maintainer from Brian Beattie to Henning
Meier-Geinitz and adds a link to the documentation and website.

This is a minor cleanup to convert 8 spaces into tabs.  There is no
functional change here.

This patch removes the US_FL_DEV_ATTACHED flag, which is now rendered
obsolete by the new hotplug system.

It also adds a comment or two about areas of code that need to be
re-examined.

This patch does the following:
(o) Add comments showing what needs to be done to complete the hot-unplug
    system.
(o) Add a BUG_ON() for (what is now) a critical failure case.
(o) Make certain that a debug print happens even if a usb_get_intfdata()
    crashes.
(o) Add an un-necessary up() to balance a down, for the auto-code-checkers.

It should fix the OOPS on attach.

This fixes a silly error where I fail to initialize a pointer early enough
for the scanning code.  If this isn't a perfect example of why
scsi_register() and scsi_add_host() aren't two separate functions, I don't
know what is.  :)

Oh, and I added a couple of comments, too.

  -  Fix an OOPS by moving the setting of the hostdata[] pointer to _before_
     the device scan starts.

This patch goes on top of the last one.  It fixes a typo in the test for
scsi_register() failure.

  -- reversed the logic of failure test for scsi_register()

The attached patch is my first implementation of SCSI hotplugging.

It's only been tested that it compiles, as I can't get the current
linux-2.5 tree from linuxusb to boot.  It dies _very_ early.  Greg, I'm not
sure if you'll want to apply this.  Linus seemed to want this very much,
and it is 2.5.x... I say go for it, but I can understand if you have
reservations.

I would definately like to see this tested by anyone who can get a kernel
to boot.

This patch is quite large.  Lots of things had to be changed.  Among them:

(o) The proc interface now uses the host number to look up the SCSI host
    structure, and then finds the usb-storage structure from that.
(o) The SCSI interface has been changed.  The code flow is now much
    clearer, as more work is done from the USB probe/detach functions than
    from auxillary functions.
(o) Names have been changed for newer conventions
(o) GUIDs have been removed
(o) The linked-list of devices has been removed, and it's associated
    semaphore
(o) All code dealing with re-attaching a device to it's old association has
    been removed
(o) Some spaces changed to tabs
(o) usb-storage now takes one directory under /proc/scsi instead of
    one per virtual-HBA
(o) All control threads now have the same name.  This could be changed back
    to the old behavior, if enough people want it.

Known problems:
(o) Testing, testing, testing
(o) More dead code needs to be cut
(o) It's a unclear how a LLD is supposed to cut off the flow of
    commands, so that the unregister() call always succeeds.  SCSI folks
    need to work on this.
(o) Probing needs to be broken down into smaller functions, probably.

Thanks to Matt Dharm and David Brownell for tracking this bug down.

  speedtouch: add a new encoding function, atmsar_encode.  Calling it amounts to doing
  atmsar_encode_aal5 followed by atmsar_encode_rawcell in one fell swoop.  It eliminates
  the need for intermediate buffers and reduces memory movement.  The following patches
  use it to simplify the send logic (and get rid of those annoying little oopsen).

This should apply to 2.5.59 too.  It seems to get rid of some pesky
hangs, on at least some hardware, but I won't have time to test it
on either VIA version ... maybe someone else will make the time?  :)

      New QH state prevents a re-activation race
	- nobody can un-halt a qh before its cleanup is done
	- resubmit-from-completion had this race (some usbtest cases)
	  as could some normal submit paths on busy endpoints (storage)
	- faster controllers would trip on this more consistently

      Queues of qtds
	- work harder to avoid ever modifing any qh in software
	- short reads block queue advance much less often
	- be more cautious with large (>~19KB) unaligned buffers

      Unlinking urbs
	- if qtd unlinked is at queue head, use its latest status
	  (main effect is reporting bytes from partial transfers)
	- another new qh state:  defer qh unlink if IAA is busy
	  (eliminates a busy-wait loop in a rare scenario)

      Enable features to improve bus utilization
	- PCI MWI ... can produce better write throughput; and by
	  using right cacheline size, sometimes read throughput too
	- USB NAK throttle ... sometimes reduces PCI access rates

      Other
	- async dump shows more funky qh+qtd states, and NAK count
	- cope with with some of the sprintf wierdness
	- periodic dump is usually smaller (so is that schedule)
      	- minor cleanups

Normally the CDC ACM devices have an subclass of 0, and the ACM subclass is
only applied to their first interface. But some have the subclass set on
the device itself, namely Motorola mobile phones. This patch takes those
devices into account.

The support for non-dma HCDs is likely the most interesting bit here.

    - makes dma calls behave sensibly when used with host controllers
      that don't use dma (including sl811).  usb_buffer_map() is a nop
      while scatterlist dma mappings fail (as they must).

    - make usb_sg_init() behave sensibly when used with non-dma hcs.
      the urbs are initted with transfer_buffer, not transfer_dma.
      this is the higher level analogue to usb_buffer_map(), so it
      needs to succeed unless there's a Real Error (tm).

    - moves two compatibility inlines from ehci.h into hcd.h so
      it'll be more practical to have the other hcds work in other
      environments (notably lk 2.4) too

    - remove URB_TIMEOUT_KILLED flag ... no device driver tests it;
      hcds don't really (uhci sets it, never reads it; sl811 doesn't
      enable the path that might set it), and it's not well defined.
      if any hcd needs such state, keep it in hc-private storage.

    - in usb_sg_wait(), use yield() instead of schedule() to let
      other activities free resources needed to continue.  (This
      was noted recently by Oliver.)

This is a minor cleanup to let per-request memory allocations block,
when the caller allows (it provided the bitmask).  The driver used
to work that way until something like 2.4.3; an update (a few months
back) to how the "dma_addr_t" hashes to a "struct ohci_td *" lets us
simplify things again.  Another benfit:  it blocks irqs for less time
on the submit path.  (The ehci driver already acts this way.)

  Some ethernet drivers other than those in .../drivers/net need generic
  MII code too and this cset shows how we do it for .../drivers/usb/net;
  For now only pegasus.c is using this feature, but as soon as we find
  more MII compliant controllers we'll put them in Makefile.mii too.
  Note: drivers which use the generic mii routines should bracket the
  code with #ifdef CONFIG_MII #endif since CONFIG_MII may not be present.
  See pegasus.c for more details.

This patch adds vendor/product ids for Artec, Canon, Compaq, Epson,
HP, and Microtek scanners. Further more, the device list was cleaned
up, sorted and duplicated entries have been removed.

  speedtouch: simplify the receive urb lifecycle: allocate them in the usb probe function,
  free them on disconnect.

  speedtouch: turn a micro race into a nano race.  The race is that an ATM device can
  be used the moment atm_dev_register returns, but you only get to fill out the
  atm_dev structure after atm_dev_register returns (this is a design flaw in the
  ATM layer).  Thus there is a small window during which you can be called with an
  incompletely set up data structure.  Workaround this by causing all ATM callbacks
  to fail if the dev_data field has not been set.  There is still a nano race if
  writing/reading the dev_data field is not atomic.  Is it atomic on all architectures?

  speedtouch: rework udsl_usb_probe error handling (for example, handle failure of
  atm_dev_register).  Do some trivial cleaning up while we're at it.

  speedtouch: roll udsl_atm_startdevice into udsl_usb_probe.

  speedtouch: use an array for rcvbufs rather than a pointer and dynamic allocation.

  speedtouch: roll udsl_atm_set_mac into udsl_usb_probe.

  speedtouch: trivial whitespace and debug message changes.

Added ids for the Dell Axim and Toshiba E740.

Thanks to Ian Molton and B.I.

  speedtouch: restore use of MODULE_DEVICE_TABLE to export usb info.  There may have
  been a problem with older 2.4 kernels, but there is none now.

Someone changed the "get string" logic to use short reads,
not long ones, a while back.  That broke many root hub
string accesses (not through tools like "lsusb"!) because
that logic didn't handle short reads quite right.

into kroah.com:/home/greg/linux/BK/gregkh-2.5