Pull scsi target updates from Nicholas Bellinger:
"Things have been calm for the most part with no new fabric drivers in
flight for v3.7 (we're up to eight now !), so this update is primarily
focused on addressing a few long-standing items within target-core and
iscsi-target fabric code.
The highlights include:
- target: Simplify fabric sense data length handling (roland)
- qla2xxx: Fix endianness of task management response code (roland)
- target: fix truncation of mode data, support zero allocation length
(paolo)
- target: Properly support zero-length commands in normal processing
path (paolo)
- iscsi-target: Correctly set 0xffffffff field within ISCSI_OP_REJECT
PDU (ronnie + nab)
- iscsi-target: Add explicit set of cache_dynamic_acls=1 for TPG
demo-mode (ronnie + nab)
- target/file: Re-enable optional fd_buffered_io=1 operation (nab +
hch)
- iscsi-target: Add MaxXmitDataSegmenthLength forr target ->
initiator MDRSL declaration (nab)
- target: Add target_submit_cmd_map_sgls for SGL fabric memory
passthrough (nab + hch)
- tcm_loop: Convert I/O path to use target_submit_cmd_map_sgls (hch +
nab)
- tcm_vhost: Convert I/O path to use target_submit_cmd_map_sgls (nab
+ hch)
The last series for adding a new target_submit_cmd_map_sgls() fabric
caller (as requested by hch) that accepts pre-allocated SGL memory
(using existing logic), along with converting tcm_loop + tcm_vhost has
only been in -next for the last days, but has gotten enough review
+testing and is clear enough a mechanical change that I think it's
reasonable to merge for -rc1 code.
Thanks again to everyone who contributed this round! Extra special
thanks to Roland (PureStorage) for tracking down the qla2xxx target
TMR response code endian issue, and to Paolo (Redhat) for resolving
the long standing zero-length CDB issues within target-core between
virtual and pSCSI backends."
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (44 commits)
iscsi-target: Bump defaults for nopin_timeout + nopin_response_timeout values
iscsit: proper endianess conversions
iscsit: use the itt_t abstract type
iscsit: add missing endianess conversion in iscsit_check_inaddr_any
iscsit: remove incorrect unlock in iscsit_build_sendtargets_resp
iscsit: mark various functions static
target/iscsi: precedence bug in iscsit_set_dataout_sequence_values()
target/usb-gadget: strlen() doesn't count the terminator
target/usb-gadget: remove duplicate initialization
tcm_vhost: Convert I/O path to use target_submit_cmd_map_sgls
target: Add control CDB READ payload zero work-around
tcm_loop: Convert I/O path to use target_submit_cmd_map_sgls
target: Add target_submit_cmd_map_sgls for SGL fabric memory passthrough
iscsi-target: Add explicit set of cache_dynamic_acls=1 for TPG demo-mode
iscsi-target: Change iscsi_target_seq_pdu_list.c to honor MaxXmitDataSegmentLength
iscsi-target: Add MaxXmitDataSegmentLength connection recovery check
iscsi-target: Convert incoming PDU payload checks to MaxXmitDataSegmentLength
iscsi-target: Enable MaxXmitDataSegmentLength operation in login path
iscsi-target: Add base MaxXmitDataSegmentLength code
target/file: Re-enable optional fd_buffered_io=1 operation
...
To understand all the Linux-USB framework, you'll use these resources:
* This source code. This is necessarily an evolving work, and
includes kerneldoc that should help you get a current overview.
("make pdfdocs", and then look at "usb.pdf" for host side and
"gadget.pdf" for peripheral side.) Also, Documentation/usb has
more information.
* The USB 2.0 specification (from www.usb.org), with supplements
such as those for USB OTG and the various device classes.
The USB specification has a good overview chapter, and USB
peripherals conform to the widely known "Chapter 9".
* Chip specifications for USB controllers. Examples include
host controllers (on PCs, servers, and more); peripheral
controllers (in devices with Linux firmware, like printers or
cell phones); and hard-wired peripherals like Ethernet adapters.
* Specifications for other protocols implemented by USB peripheral
functions. Some are vendor-specific; others are vendor-neutral
but just standardized outside of the www.usb.org team.
Here is a list of what each subdirectory here is, and what is contained in
them.
core/ - This is for the core USB host code, including the
usbfs files and the hub class driver ("khubd").
host/ - This is for USB host controller drivers. This
includes UHCI, OHCI, EHCI, and others that might
be used with more specialized "embedded" systems.
gadget/ - This is for USB peripheral controller drivers and
the various gadget drivers which talk to them.
Individual USB driver directories. A new driver should be added to the
first subdirectory in the list below that it fits into.
image/ - This is for still image drivers, like scanners or
digital cameras.
../input/ - This is for any driver that uses the input subsystem,
like keyboard, mice, touchscreens, tablets, etc.
../media/ - This is for multimedia drivers, like video cameras,
radios, and any other drivers that talk to the v4l
subsystem.
../net/ - This is for network drivers.
serial/ - This is for USB to serial drivers.
storage/ - This is for USB mass-storage drivers.
class/ - This is for all USB device drivers that do not fit
into any of the above categories, and work for a range
of USB Class specified devices.
misc/ - This is for all USB device drivers that do not fit
into any of the above categories.