Merge branch 'linux-2.6' into for-2.6.24

4 files changed, 476 insertions, 255 deletions

diff --git a/Documentation/crypto/async-tx-api.txt b/Documentation/crypto/async-tx-api.txt
new file mode 100644
index 0000000..c1e9545
--- /dev/null
+++ b/Documentation/crypto/async-tx-api.txt
@@ -0,0 +1,219 @@
+		 Asynchronous Transfers/Transforms API
+
+1 INTRODUCTION
+
+2 GENEALOGY
+
+3 USAGE
+3.1 General format of the API
+3.2 Supported operations
+3.3 Descriptor management
+3.4 When does the operation execute?
+3.5 When does the operation complete?
+3.6 Constraints
+3.7 Example
+
+4 DRIVER DEVELOPER NOTES
+4.1 Conformance points
+4.2 "My application needs finer control of hardware channels"
+
+5 SOURCE
+
+---
+
+1 INTRODUCTION
+
+The async_tx API provides methods for describing a chain of asynchronous
+bulk memory transfers/transforms with support for inter-transactional
+dependencies.  It is implemented as a dmaengine client that smooths over
+the details of different hardware offload engine implementations.  Code
+that is written to the API can optimize for asynchronous operation and
+the API will fit the chain of operations to the available offload
+resources.
+
+2 GENEALOGY
+
+The API was initially designed to offload the memory copy and
+xor-parity-calculations of the md-raid5 driver using the offload engines
+present in the Intel(R) Xscale series of I/O processors.  It also built
+on the 'dmaengine' layer developed for offloading memory copies in the
+network stack using Intel(R) I/OAT engines.  The following design
+features surfaced as a result:
+1/ implicit synchronous path: users of the API do not need to know if
+   the platform they are running on has offload capabilities.  The
+   operation will be offloaded when an engine is available and carried out
+   in software otherwise.
+2/ cross channel dependency chains: the API allows a chain of dependent
+   operations to be submitted, like xor->copy->xor in the raid5 case.  The
+   API automatically handles cases where the transition from one operation
+   to another implies a hardware channel switch.
+3/ dmaengine extensions to support multiple clients and operation types
+   beyond 'memcpy'
+
+3 USAGE
+
+3.1 General format of the API:
+struct dma_async_tx_descriptor *
+async_<operation>(<op specific parameters>,
+		  enum async_tx_flags flags,
+        	  struct dma_async_tx_descriptor *dependency,
+        	  dma_async_tx_callback callback_routine,
+		  void *callback_parameter);
+
+3.2 Supported operations:
+memcpy       - memory copy between a source and a destination buffer
+memset       - fill a destination buffer with a byte value
+xor          - xor a series of source buffers and write the result to a
+	       destination buffer
+xor_zero_sum - xor a series of source buffers and set a flag if the
+	       result is zero.  The implementation attempts to prevent
+	       writes to memory
+
+3.3 Descriptor management:
+The return value is non-NULL and points to a 'descriptor' when the operation
+has been queued to execute asynchronously.  Descriptors are recycled
+resources, under control of the offload engine driver, to be reused as
+operations complete.  When an application needs to submit a chain of
+operations it must guarantee that the descriptor is not automatically recycled
+before the dependency is submitted.  This requires that all descriptors be
+acknowledged by the application before the offload engine driver is allowed to
+recycle (or free) the descriptor.  A descriptor can be acked by one of the
+following methods:
+1/ setting the ASYNC_TX_ACK flag if no child operations are to be submitted
+2/ setting the ASYNC_TX_DEP_ACK flag to acknowledge the parent
+   descriptor of a new operation.
+3/ calling async_tx_ack() on the descriptor.
+
+3.4 When does the operation execute?
+Operations do not immediately issue after return from the
+async_<operation> call.  Offload engine drivers batch operations to
+improve performance by reducing the number of mmio cycles needed to
+manage the channel.  Once a driver-specific threshold is met the driver
+automatically issues pending operations.  An application can force this
+event by calling async_tx_issue_pending_all().  This operates on all
+channels since the application has no knowledge of channel to operation
+mapping.
+
+3.5 When does the operation complete?
+There are two methods for an application to learn about the completion
+of an operation.
+1/ Call dma_wait_for_async_tx().  This call causes the CPU to spin while
+   it polls for the completion of the operation.  It handles dependency
+   chains and issuing pending operations.
+2/ Specify a completion callback.  The callback routine runs in tasklet
+   context if the offload engine driver supports interrupts, or it is
+   called in application context if the operation is carried out
+   synchronously in software.  The callback can be set in the call to
+   async_<operation>, or when the application needs to submit a chain of
+   unknown length it can use the async_trigger_callback() routine to set a
+   completion interrupt/callback at the end of the chain.
+
+3.6 Constraints:
+1/ Calls to async_<operation> are not permitted in IRQ context.  Other
+   contexts are permitted provided constraint #2 is not violated.
+2/ Completion callback routines cannot submit new operations.  This
+   results in recursion in the synchronous case and spin_locks being
+   acquired twice in the asynchronous case.
+
+3.7 Example:
+Perform a xor->copy->xor operation where each operation depends on the
+result from the previous operation:
+
+void complete_xor_copy_xor(void *param)
+{
+	printk("complete\n");
+}
+
+int run_xor_copy_xor(struct page **xor_srcs,
+		     int xor_src_cnt,
+		     struct page *xor_dest,
+		     size_t xor_len,
+		     struct page *copy_src,
+		     struct page *copy_dest,
+		     size_t copy_len)
+{
+	struct dma_async_tx_descriptor *tx;
+
+	tx = async_xor(xor_dest, xor_srcs, 0, xor_src_cnt, xor_len,
+		       ASYNC_TX_XOR_DROP_DST, NULL, NULL, NULL);
+	tx = async_memcpy(copy_dest, copy_src, 0, 0, copy_len,
+			  ASYNC_TX_DEP_ACK, tx, NULL, NULL);
+	tx = async_xor(xor_dest, xor_srcs, 0, xor_src_cnt, xor_len,
+		       ASYNC_TX_XOR_DROP_DST | ASYNC_TX_DEP_ACK | ASYNC_TX_ACK,
+		       tx, complete_xor_copy_xor, NULL);
+
+	async_tx_issue_pending_all();
+}
+
+See include/linux/async_tx.h for more information on the flags.  See the
+ops_run_* and ops_complete_* routines in drivers/md/raid5.c for more
+implementation examples.
+
+4 DRIVER DEVELOPMENT NOTES
+4.1 Conformance points:
+There are a few conformance points required in dmaengine drivers to
+accommodate assumptions made by applications using the async_tx API:
+1/ Completion callbacks are expected to happen in tasklet context
+2/ dma_async_tx_descriptor fields are never manipulated in IRQ context
+3/ Use async_tx_run_dependencies() in the descriptor clean up path to
+   handle submission of dependent operations
+
+4.2 "My application needs finer control of hardware channels"
+This requirement seems to arise from cases where a DMA engine driver is
+trying to support device-to-memory DMA.  The dmaengine and async_tx
+implementations were designed for offloading memory-to-memory
+operations; however, there are some capabilities of the dmaengine layer
+that can be used for platform-specific channel management.
+Platform-specific constraints can be handled by registering the
+application as a 'dma_client' and implementing a 'dma_event_callback' to
+apply a filter to the available channels in the system.  Before showing
+how to implement a custom dma_event callback some background of
+dmaengine's client support is required.
+
+The following routines in dmaengine support multiple clients requesting
+use of a channel:
+- dma_async_client_register(struct dma_client *client)
+- dma_async_client_chan_request(struct dma_client *client)
+
+dma_async_client_register takes a pointer to an initialized dma_client
+structure.  It expects that the 'event_callback' and 'cap_mask' fields
+are already initialized.
+
+dma_async_client_chan_request triggers dmaengine to notify the client of
+all channels that satisfy the capability mask.  It is up to the client's
+event_callback routine to track how many channels the client needs and
+how many it is currently using.  The dma_event_callback routine returns a
+dma_state_client code to let dmaengine know the status of the
+allocation.
+
+Below is the example of how to extend this functionality for
+platform-specific filtering of the available channels beyond the
+standard capability mask:
+
+static enum dma_state_client
+my_dma_client_callback(struct dma_client *client,
+			struct dma_chan *chan, enum dma_state state)
+{
+	struct dma_device *dma_dev;
+	struct my_platform_specific_dma *plat_dma_dev;
+	
+	dma_dev = chan->device;
+	plat_dma_dev = container_of(dma_dev,
+				    struct my_platform_specific_dma,
+				    dma_dev);
+
+	if (!plat_dma_dev->platform_specific_capability)
+		return DMA_DUP;
+
+	. . .
+}
+
+5 SOURCE
+include/linux/dmaengine.h: core header file for DMA drivers and clients
+drivers/dma/dmaengine.c: offload engine channel management routines
+drivers/dma/: location for offload engine drivers
+include/linux/async_tx.h: core header file for the async_tx api
+crypto/async_tx/async_tx.c: async_tx interface to dmaengine and common code
+crypto/async_tx/async_memcpy.c: copy offload
+crypto/async_tx/async_memset.c: memory fill offload
+crypto/async_tx/async_xor.c: xor and xor zero sum offload
diff --git a/Documentation/devices.txt b/Documentation/devices.txt
index 8de132a..6c46730 100644
--- a/Documentation/devices.txt
+++ b/Documentation/devices.txt
@@ -94,6 +94,8 @@ Your cooperation is appreciated.
 		  9 = /dev/urandom	Faster, less secure random number gen.
 		 10 = /dev/aio		Asynchronous I/O notification interface
 		 11 = /dev/kmsg		Writes to this come out as printk's
+		 12 = /dev/oldmem	Used by crashdump kernels to access
+					the memory of the kernel that crashed.
 
   1 block	RAM disk
 		  0 = /dev/ram0		First RAM disk
diff --git a/Documentation/input/iforce-protocol.txt b/Documentation/input/iforce-protocol.txt
index 95df4ca..8777d2d 100644
--- a/Documentation/input/iforce-protocol.txt
+++ b/Documentation/input/iforce-protocol.txt
@@ -1,254 +1,254 @@
-** Introduction

-This document describes what I managed to discover about the protocol used to

-specify force effects to I-Force 2.0 devices.  None of this information comes

-from Immerse. That's why you should not trust what is written in this

-document. This document is intended to help understanding the protocol.

-This is not a reference. Comments and corrections are welcome.  To contact me,

-send an email to: deneux@ifrance.com

-

-** WARNING **

-I may not be held responsible for any dammage or harm caused if you try to

-send data to your I-Force device based on what you read in this document.

-

-** Preliminary Notes:

-All values are hexadecimal with big-endian encoding (msb on the left). Beware,

-values inside packets are encoded using little-endian.  Bytes whose roles are

-unknown are marked ???  Information that needs deeper inspection is marked (?)

-

-** General form of a packet **

-This is how packets look when the device uses the rs232 to communicate.

-2B OP LEN DATA CS

-CS is the checksum. It is equal to the exclusive or of all bytes.

-

-When using USB:

-OP DATA

-The 2B, LEN and CS fields have disappeared, probably because USB handles frames and

-data corruption is handled or unsignificant.

-

-First, I describe effects that are sent by the device to the computer

-

-** Device input state

-This packet is used to indicate the state of each button and the value of each

-axis

-OP= 01 for a joystick, 03 for a wheel

-LEN= Varies from device to device

-00 X-Axis lsb

-01 X-Axis msb

-02 Y-Axis lsb, or gas pedal for a wheel

-03 Y-Axis msb, or brake pedal for a wheel

-04 Throttle

-05 Buttons

-06 Lower 4 bits: Buttons

-   Upper 4 bits: Hat

-07 Rudder

-

-** Device effects states

-OP= 02

-LEN= Varies

-00 ? Bit 1 (Value 2) is the value of the deadman switch

-01 Bit 8 is set if the effect is playing. Bits 0 to 7 are the effect id.

-02 ??

-03 Address of parameter block changed (lsb)

-04 Address of parameter block changed (msb)

-05 Address of second parameter block changed (lsb)

-... depending on the number of parameter blocks updated

-

-** Force effect **

-OP=  01

-LEN= 0e

-00 Channel (when playing several effects at the same time, each must be assigned a channel)

-01 Wave form

-	Val 00 Constant

-	Val 20 Square

-	Val 21 Triangle

-	Val 22 Sine

-	Val 23 Sawtooth up

-	Val 24 Sawtooth down

-	Val 40 Spring (Force = f(pos))

-	Val 41 Friction (Force = f(velocity)) and Inertia (Force = f(acceleration))

-

-	

-02 Axes affected and trigger

-	Bits 4-7: Val 2 = effect along one axis. Byte 05 indicates direction

-	          Val 4 = X axis only. Byte 05 must contain 5a

-	          Val 8 = Y axis only. Byte 05 must contain b4

-	          Val c = X and Y axes. Bytes 05 must contain 60

-	Bits 0-3: Val 0 = No trigger

-	          Val x+1 = Button x triggers the effect

-	When the whole byte is 0, cancel the previously set trigger

-

-03-04 Duration of effect (little endian encoding, in ms)

-

-05 Direction of effect, if applicable. Else, see 02 for value to assign.

-

-06-07 Minimum time between triggering.

-

-08-09 Address of periodicity or magnitude parameters

-0a-0b Address of attack and fade parameters, or ffff if none.

-*or*

-08-09 Address of interactive parameters for X-axis, or ffff if not applicable

-0a-0b Address of interactive parameters for Y-axis, or ffff if not applicable

-

-0c-0d Delay before execution of effect (little endian encoding, in ms)

-

-

-** Time based parameters **

-

-*** Attack and fade ***

-OP=  02

-LEN= 08

-00-01 Address where to store the parameteres

-02-03 Duration of attack (little endian encoding, in ms)

-04 Level at end of attack. Signed byte.

-05-06 Duration of fade.

-07 Level at end of fade.

-

-*** Magnitude ***

-OP=  03

-LEN= 03

-00-01 Address

-02 Level. Signed byte.

-

-*** Periodicity ***

-OP=  04

-LEN= 07

-00-01 Address

-02 Magnitude. Signed byte.

-03 Offset. Signed byte.

-04 Phase. Val 00 = 0 deg, Val 40 = 90 degs.

-05-06 Period (little endian encoding, in ms)

-

-** Interactive parameters **

-OP=  05

-LEN= 0a

-00-01 Address

-02 Positive Coeff

-03 Negative Coeff

-04+05 Offset (center)

-06+07 Dead band (Val 01F4 = 5000 (decimal))

-08 Positive saturation (Val 0a = 1000 (decimal) Val 64 = 10000 (decimal))

-09 Negative saturation

-

-The encoding is a bit funny here: For coeffs, these are signed values. The

-maximum value is 64 (100 decimal), the min is 9c.

-For the offset, the minimum value is FE0C, the maximum value is 01F4.

-For the deadband, the minimum value is 0, the max is 03E8.

-

-** Controls **

-OP=  41

-LEN= 03

-00 Channel

-01 Start/Stop

-	Val 00: Stop

-	Val 01: Start and play once.

-	Val 41: Start and play n times (See byte 02 below)

-02 Number of iterations n.

-

-** Init **

-

-*** Querying features ***

-OP=  ff

-Query command. Length varies according to the query type.

-The general format of this packet is:

-ff 01 QUERY [INDEX] CHECKSUM

-reponses are of the same form:

-FF LEN QUERY VALUE_QUERIED CHECKSUM2

-where LEN = 1 + length(VALUE_QUERIED)

-

-**** Query ram size ****

-QUERY = 42 ('B'uffer size)

-The device should reply with the same packet plus two additionnal bytes

-containing the size of the memory:

-ff 03 42 03 e8 CS would mean that the device has 1000 bytes of ram available.

-

-**** Query number of effects ****

-QUERY = 4e ('N'umber of effects)

-The device should respond by sending the number of effects that can be played

-at the same time (one byte)

-ff 02 4e 14 CS would stand for 20 effects.

-

-**** Vendor's id ****

-QUERY = 4d ('M'anufacturer)

-Query the vendors'id (2 bytes)

-

-**** Product id *****

-QUERY = 50 ('P'roduct)

-Query the product id (2 bytes)

-

-**** Open device ****

-QUERY = 4f ('O'pen) 

-No data returned.

-

-**** Close device *****

-QUERY = 43 ('C')lose

-No data returned.

-

-**** Query effect ****

-QUERY = 45 ('E') 

-Send effect type.

-Returns nonzero if supported (2 bytes)

-

-**** Firmware Version ****

-QUERY = 56 ('V'ersion)

-Sends back 3 bytes - major, minor, subminor

-

-*** Initialisation of the device ***

-

-**** Set Control ****

-!!! Device dependent, can be different on different models !!!

-OP=  40 <idx> <val> [<val>]

-LEN= 2 or 3

-00 Idx

-   Idx 00 Set dead zone (0..2048) 

-   Idx 01 Ignore Deadman sensor (0..1)     

-   Idx 02 Enable comm watchdog (0..1)     

-   Idx 03 Set the strength of the spring (0..100)   

-   Idx 04 Enable or disable the spring (0/1)

-   Idx 05 Set axis saturation threshold (0..2048) 

-

-**** Set Effect State ****

-OP=  42 <val>

-LEN= 1

-00 State

-   Bit 3 Pause force feedback

-   Bit 2 Enable force feedback

-   Bit 0 Stop all effects

-

-**** Set overall gain ****

-OP=  43 <val>

-LEN= 1

-00 Gain

-   Val 00 = 0%

-   Val 40 = 50%

-   Val 80 = 100%

-

-** Parameter memory **

-

-Each device has a certain amount of memory to store parameters of effects.

-The amount of RAM may vary, I encountered values from 200 to 1000 bytes. Below

-is the amount of memory apparently needed for every set of parameters:

- - period : 0c

- - magnitude : 02

- - attack and fade : 0e

- - interactive : 08

-

-** Appendix: How to study the protocol ? **

-

-1. Generate effects using the force editor provided with the DirectX SDK, or use Immersion Studio (freely available at their web site in the developer section: www.immersion.com)

-2. Start a soft spying RS232 or USB (depending on where you connected your joystick/wheel). I used ComPortSpy from fCoder (alpha version!)

-3. Play the effect, and watch what happens on the spy screen.

-

-A few words about ComPortSpy:

-At first glance, this soft seems, hum, well... buggy. In fact, data appear with a few seconds latency. Personnaly, I restart it every time I play an effect.

-Remember it's free (as in free beer) and alpha!

-

-** URLS **

-Check www.immerse.com for Immersion Studio, and www.fcoder.com for ComPortSpy.

-

-** Author of this document **

-Johann Deneux <deneux@ifrance.com>

-Home page at http://www.esil.univ-mrs.fr/~jdeneux/projects/ff/

-

-Additions by Vojtech Pavlik.

-

-I-Force is trademark of Immersion Corp.

+** Introduction
+This document describes what I managed to discover about the protocol used to
+specify force effects to I-Force 2.0 devices.  None of this information comes
+from Immerse. That's why you should not trust what is written in this
+document. This document is intended to help understanding the protocol.
+This is not a reference. Comments and corrections are welcome.  To contact me,
+send an email to: deneux@ifrance.com
+
+** WARNING **
+I may not be held responsible for any dammage or harm caused if you try to
+send data to your I-Force device based on what you read in this document.
+
+** Preliminary Notes:
+All values are hexadecimal with big-endian encoding (msb on the left). Beware,
+values inside packets are encoded using little-endian.  Bytes whose roles are
+unknown are marked ???  Information that needs deeper inspection is marked (?)
+
+** General form of a packet **
+This is how packets look when the device uses the rs232 to communicate.
+2B OP LEN DATA CS
+CS is the checksum. It is equal to the exclusive or of all bytes.
+
+When using USB:
+OP DATA
+The 2B, LEN and CS fields have disappeared, probably because USB handles frames and
+data corruption is handled or unsignificant.
+
+First, I describe effects that are sent by the device to the computer
+
+** Device input state
+This packet is used to indicate the state of each button and the value of each
+axis
+OP= 01 for a joystick, 03 for a wheel
+LEN= Varies from device to device
+00 X-Axis lsb
+01 X-Axis msb
+02 Y-Axis lsb, or gas pedal for a wheel
+03 Y-Axis msb, or brake pedal for a wheel
+04 Throttle
+05 Buttons
+06 Lower 4 bits: Buttons
+   Upper 4 bits: Hat
+07 Rudder
+
+** Device effects states
+OP= 02
+LEN= Varies
+00 ? Bit 1 (Value 2) is the value of the deadman switch
+01 Bit 8 is set if the effect is playing. Bits 0 to 7 are the effect id.
+02 ??
+03 Address of parameter block changed (lsb)
+04 Address of parameter block changed (msb)
+05 Address of second parameter block changed (lsb)
+... depending on the number of parameter blocks updated
+
+** Force effect **
+OP=  01
+LEN= 0e
+00 Channel (when playing several effects at the same time, each must be assigned a channel)
+01 Wave form
+	Val 00 Constant
+	Val 20 Square
+	Val 21 Triangle
+	Val 22 Sine
+	Val 23 Sawtooth up
+	Val 24 Sawtooth down
+	Val 40 Spring (Force = f(pos))
+	Val 41 Friction (Force = f(velocity)) and Inertia (Force = f(acceleration))
+
+
+02 Axes affected and trigger
+	Bits 4-7: Val 2 = effect along one axis. Byte 05 indicates direction
+	          Val 4 = X axis only. Byte 05 must contain 5a
+	          Val 8 = Y axis only. Byte 05 must contain b4
+	          Val c = X and Y axes. Bytes 05 must contain 60
+	Bits 0-3: Val 0 = No trigger
+	          Val x+1 = Button x triggers the effect
+	When the whole byte is 0, cancel the previously set trigger
+
+03-04 Duration of effect (little endian encoding, in ms)
+
+05 Direction of effect, if applicable. Else, see 02 for value to assign.
+
+06-07 Minimum time between triggering.
+
+08-09 Address of periodicity or magnitude parameters
+0a-0b Address of attack and fade parameters, or ffff if none.
+*or*
+08-09 Address of interactive parameters for X-axis, or ffff if not applicable
+0a-0b Address of interactive parameters for Y-axis, or ffff if not applicable
+
+0c-0d Delay before execution of effect (little endian encoding, in ms)
+
+
+** Time based parameters **
+
+*** Attack and fade ***
+OP=  02
+LEN= 08
+00-01 Address where to store the parameteres
+02-03 Duration of attack (little endian encoding, in ms)
+04 Level at end of attack. Signed byte.
+05-06 Duration of fade.
+07 Level at end of fade.
+
+*** Magnitude ***
+OP=  03
+LEN= 03
+00-01 Address
+02 Level. Signed byte.
+
+*** Periodicity ***
+OP=  04
+LEN= 07
+00-01 Address
+02 Magnitude. Signed byte.
+03 Offset. Signed byte.
+04 Phase. Val 00 = 0 deg, Val 40 = 90 degs.
+05-06 Period (little endian encoding, in ms)
+
+** Interactive parameters **
+OP=  05
+LEN= 0a
+00-01 Address
+02 Positive Coeff
+03 Negative Coeff
+04+05 Offset (center)
+06+07 Dead band (Val 01F4 = 5000 (decimal))
+08 Positive saturation (Val 0a = 1000 (decimal) Val 64 = 10000 (decimal))
+09 Negative saturation
+
+The encoding is a bit funny here: For coeffs, these are signed values. The
+maximum value is 64 (100 decimal), the min is 9c.
+For the offset, the minimum value is FE0C, the maximum value is 01F4.
+For the deadband, the minimum value is 0, the max is 03E8.
+
+** Controls **
+OP=  41
+LEN= 03
+00 Channel
+01 Start/Stop
+	Val 00: Stop
+	Val 01: Start and play once.
+	Val 41: Start and play n times (See byte 02 below)
+02 Number of iterations n.
+
+** Init **
+
+*** Querying features ***
+OP=  ff
+Query command. Length varies according to the query type.
+The general format of this packet is:
+ff 01 QUERY [INDEX] CHECKSUM
+reponses are of the same form:
+FF LEN QUERY VALUE_QUERIED CHECKSUM2
+where LEN = 1 + length(VALUE_QUERIED)
+
+**** Query ram size ****
+QUERY = 42 ('B'uffer size)
+The device should reply with the same packet plus two additionnal bytes
+containing the size of the memory:
+ff 03 42 03 e8 CS would mean that the device has 1000 bytes of ram available.
+
+**** Query number of effects ****
+QUERY = 4e ('N'umber of effects)
+The device should respond by sending the number of effects that can be played
+at the same time (one byte)
+ff 02 4e 14 CS would stand for 20 effects.
+
+**** Vendor's id ****
+QUERY = 4d ('M'anufacturer)
+Query the vendors'id (2 bytes)
+
+**** Product id *****
+QUERY = 50 ('P'roduct)
+Query the product id (2 bytes)
+
+**** Open device ****
+QUERY = 4f ('O'pen)
+No data returned.
+
+**** Close device *****
+QUERY = 43 ('C')lose
+No data returned.
+
+**** Query effect ****
+QUERY = 45 ('E')
+Send effect type.
+Returns nonzero if supported (2 bytes)
+
+**** Firmware Version ****
+QUERY = 56 ('V'ersion)
+Sends back 3 bytes - major, minor, subminor
+
+*** Initialisation of the device ***
+
+**** Set Control ****
+!!! Device dependent, can be different on different models !!!
+OP=  40 <idx> <val> [<val>]
+LEN= 2 or 3
+00 Idx
+   Idx 00 Set dead zone (0..2048)
+   Idx 01 Ignore Deadman sensor (0..1)
+   Idx 02 Enable comm watchdog (0..1)
+   Idx 03 Set the strength of the spring (0..100)
+   Idx 04 Enable or disable the spring (0/1)
+   Idx 05 Set axis saturation threshold (0..2048)
+
+**** Set Effect State ****
+OP=  42 <val>
+LEN= 1
+00 State
+   Bit 3 Pause force feedback
+   Bit 2 Enable force feedback
+   Bit 0 Stop all effects
+
+**** Set overall gain ****
+OP=  43 <val>
+LEN= 1
+00 Gain
+   Val 00 = 0%
+   Val 40 = 50%
+   Val 80 = 100%
+
+** Parameter memory **
+
+Each device has a certain amount of memory to store parameters of effects.
+The amount of RAM may vary, I encountered values from 200 to 1000 bytes. Below
+is the amount of memory apparently needed for every set of parameters:
+ - period : 0c
+ - magnitude : 02
+ - attack and fade : 0e
+ - interactive : 08
+
+** Appendix: How to study the protocol ? **
+
+1. Generate effects using the force editor provided with the DirectX SDK, or use Immersion Studio (freely available at their web site in the developer section: www.immersion.com)
+2. Start a soft spying RS232 or USB (depending on where you connected your joystick/wheel). I used ComPortSpy from fCoder (alpha version!)
+3. Play the effect, and watch what happens on the spy screen.
+
+A few words about ComPortSpy:
+At first glance, this soft seems, hum, well... buggy. In fact, data appear with a few seconds latency. Personnaly, I restart it every time I play an effect.
+Remember it's free (as in free beer) and alpha!
+
+** URLS **
+Check www.immerse.com for Immersion Studio, and www.fcoder.com for ComPortSpy.
+
+** Author of this document **
+Johann Deneux <deneux@ifrance.com>
+Home page at http://www.esil.univ-mrs.fr/~jdeneux/projects/ff/
+
+Additions by Vojtech Pavlik.
+
+I-Force is trademark of Immersion Corp.
diff --git a/Documentation/lguest/lguest.c b/Documentation/lguest/lguest.c
index f791840..73c5f1f 100644
--- a/Documentation/lguest/lguest.c
+++ b/Documentation/lguest/lguest.c
@@ -882,7 +882,7 @@ static u32 handle_block_output(int fd, const struct iovec *iov,
 		 * of the block file (possibly extending it). */
 		if (off + len > device_len) {
 			/* Trim it back to the correct length */
-			ftruncate(dev->fd, device_len);
+			ftruncate64(dev->fd, device_len);
 			/* Die, bad Guest, die. */
 			errx(1, "Write past end %llu+%u", off, len);
 		}