linux-toradex.git/drivers/usb/storage/usb.h, branch v3.0.23

usb-storage: fix freezing of the scanning thread

2012-03-01T00:34:27+00:00

commit bb94a406682770a35305daaa241ccdb7cab399de upstream.

This patch (as1521b) fixes the interaction between usb-storage's
scanning thread and the freezer.  The current implementation has a
race: If the device is unplugged shortly after being plugged in and
just as a system sleep begins, the scanning thread may get frozen
before the khubd task.  Khubd won't be able to freeze until the
disconnect processing is complete, and the disconnect processing can't
proceed until the scanning thread finishes, so the sleep transition
will fail.

The implementation in the 3.2 kernel suffers from an additional
problem.  There the scanning thread calls set_freezable_with_signal(),
and the signals sent by the freezer will mess up the thread's I/O
delays, which are all interruptible.

The solution to both problems is the same: Replace the kernel thread
used for scanning with a delayed-work routine on the system freezable
work queue.  Freezable work queues have the nice property that you can
cancel a work item even while the work queue is frozen, and no signals
are needed.

The 3.2 version of this patch solves the problem in Bugzilla #42730.

Signed-off-by: Alan Stern 
Acked-by: Seth Forshee 
Signed-off-by: Greg Kroah-Hartman

usb-storage: redo incorrect reads

2011-06-07T16:05:42+00:00

Some USB mass-storage devices have bugs that cause them not to handle
the first READ(10) command they receive correctly.  The Corsair
Padlock v2 returns completely bogus data for its first read (possibly
it returns the data in encrypted form even though the device is
supposed to be unlocked).  The Feiya SD/SDHC card reader fails to
complete the first READ(10) command after it is plugged in or after a
new card is inserted, returning a status code that indicates it thinks
the command was invalid, which prevents the kernel from retrying the
read.

Since the first read of a new device or a new medium is for the
partition sector, the kernel is unable to retrieve the device's
partition table.  Users have to manually issue an "hdparm -z" or
"blockdev --rereadpt" command before they can access the device.

This patch (as1470) works around the problem.  It adds a new quirk
flag, US_FL_INVALID_READ10, indicating that the first READ(10) should
always be retried immediately, as should any failing READ(10) commands
(provided the preceding READ(10) command succeeded, to avoid getting
stuck in a loop).  The patch also adds appropriate unusual_devs
entries containing the new flag.

Signed-off-by: Alan Stern 
Tested-by: Sven Geggus 
Tested-by: Paul Hartman 
CC: Matthew Dharm 
CC: 
Signed-off-by: Greg Kroah-Hartman

USB: remove uses of URB_NO_SETUP_DMA_MAP

2010-05-20T20:21:31+00:00

This patch (as1350) removes all usages of coherent buffers for USB
control-request setup-packet buffers.  There's no good reason to
reserve coherent memory for these things; control requests are hardly
ever used in large quantity (the major exception is firmware
transfers, and they aren't time-critical).  Furthermore, only seven
drivers used it.  We might as well always use streaming DMA mappings
for setup-packet buffers, and remove some extra complexity from
usbcore.

The DMA-mapping portion of hcd.c is currently in flux.  A separate
patch will be submitted to remove support for URB_NO_SETUP_DMA_MAP
after everything else settles down.  The removal should go smoothly,
as by then nobody will be using it.

Signed-off-by: Alan Stern 
Signed-off-by: Greg Kroah-Hartman

USB: usb-storage: Associate the name of the interface with the scsi host

2009-12-11T19:55:13+00:00

Instead of reporting "SCSI emulation for USB Mass Storage devices",
report "usb-storage 1-4:1.0".

Signed-off-by: Matthew Wilcox 
Acked-by: Alan Stern 
Signed-off-by: Greg Kroah-Hartman

usb-storage: prepare for subdriver separation

2009-03-24T23:20:34+00:00

This patch (as1206) is the first step in converting usb-storage's
subdrivers into separate modules.  It makes the following large-scale
changes:

	Remove a bunch of unnecessary #ifdef's from usb_usual.h.
	Not truly necessary, but it does clean things up.

	Move the USB device-ID table (which is duplicated between
	libusual and usb-storage) into its own source file,
	usual-tables.c, and arrange for this to be linked with
	either libusual or usb-storage according to whether
	USB_LIBUSUAL is configured.

	Add to usual-tables.c a new usb_usual_ignore_device()
	function to detect whether a particular device needs to be
	managed by a subdriver and not by the standard handlers
	in usb-storage.

	Export a whole bunch of functions in usb-storage, renaming
	some of them because their names don't already begin with
	"usb_stor_".  These functions will be needed by the new
	subdriver modules.

	Split usb-storage's probe routine into two functions.
	The subdrivers will call the probe1 routine, then fill in
	their transport and protocol settings, and then call the
	probe2 routine.

	Take the default cases and error checking out of
	get_transport() and get_protocol(), which run during
	probe1, and instead put a check for invalid transport
	or protocol values into the probe2 function.

	Add a new probe routine to be used for standard devices,
	i.e., those that don't need a subdriver.  This new routine
	checks whether the device should be ignored (because it
	should be handled by ub or by a subdriver), and if not,
	calls the probe1 and probe2 functions.

Signed-off-by: Alan Stern 
CC: Matthew Dharm 
Signed-off-by: Greg Kroah-Hartman

USB: storage: add last-sector hacks

2009-01-07T18:00:11+00:00

This patch (as1189b) adds some hacks to usb-storage for dealing with
the growing problems involving bad capacity values and last-sector
accesses:

	A new flag, US_FL_CAPACITY_OK, is created to indicate that
	the device is known to report its capacity correctly.  An
	unusual_devs entry for Linux's own File-backed Storage Gadget
	is added with this flag set, since g_file_storage always
	reports the correct capacity and since the capacity need
	not be even (it is determined by the size of the backing
	file).

	An entry in unusual_devs.h which has only the CAPACITY_OK
	flag set shouldn't prejudice libusual, since the device will
	work perfectly well with either usb-storage or ub.  So a
	new macro, COMPLIANT_DEV, is added to let libusual know
	about these entries.

	When a last-sector access succeeds and the total number of
	sectors is odd (the unexpected case, in which guessing that
	the number is even might cause trouble), a WARN is triggered.
	The kerneloops.org project will collect these warnings,
	allowing us to add CAPACITY_OK flags for the devices in
	question before implementing the default-to-even heuristic.
	If users want to prevent the stack dump produced by the WARN,
	they can disable the hack by adding an unusual_devs entry
	for their device with the CAPACITY_OK flag.

	When a last-sector access fails three times in a row and
	neither the FIX_CAPACITY nor the CAPACITY_OK flag is set,
	we assume the last-sector bug is present.  We replace the
	existing status and sense data with values that will cause
	the SCSI core to fail the access immediately rather than
	retry indefinitely.  This should fix the difficulties
	people have been having with Nokia phones.

Signed-off-by: Alan Stern 
Cc: stable 
Signed-off-by: Greg Kroah-Hartman

USB: usb-storage: remove us->sensebuf

2009-01-07T17:59:54+00:00

This patch (as1171) removes us->sensebuf, since it isn't used anywhere.

Signed-off-by: Alan Stern 
Signed-off-by: Greg Kroah-Hartman

USB: remove CVS keywords

2008-07-21T22:15:55+00:00

This patch removes CVS keywords that weren't updated for a long time
from comments.

Signed-off-by: Adrian Bunk 
Signed-off-by: Greg Kroah-Hartman

usb-storage: implement "soft" unbinding

2008-07-21T22:15:54+00:00

This patch (as1092) implements "soft" unbinding for usb-storage.  When
the disconnect routine is called, all commands and reset delays are
allowed to complete normally until after scsi_remove_host() returns.
This means that the commands needed for an orderly shutdown will be
sent through to the device.

Unlike before, the driver will now execute every command that it
accepts.  Hence there's no need for special code to catch unexecuted
commands and fail them.

The new sequence of events when disconnect runs goes as follows:

	If the device is truly unplugged, set the DISCONNECTING
	flag so we won't try to access it any more.

	If the SCSI-scanning thread hasn't started up yet, prevent
	it from doing anything by setting the new DONT_SCAN flag.
	Then wake it up and wait for it to terminate.

	Remove the SCSI host.  This unbinds the upper-level drivers,
	doing an orderly shutdown.  Commands sent to quiesce the
	device will be transmitted normally, unless the device is
	unplugged.

	Set the DISCONNECTING flag so that we won't accept any new
	commands that might get submitted (there aren't supposed to be
	any) and we won't try to access the device for resets.

	Tell the control thread to exit by waking it up with no
	pending command, and wait for it to terminate.

	Go on to do all the other normal stuff: releasing resources,
	freeing memory, and so on.

Signed-off-by: Alan Stern 
Signed-off-by: Greg Kroah-Hartman

usb-storage: change remaining semaphore to completion

2008-07-21T22:15:53+00:00

This patch (as1090) converts the one remaining semaphore in
usb-storage into a completion.

Signed-off-by: Alan Stern 
Cc: Matthew Dharm 
Signed-off-by: Greg Kroah-Hartman