1.\" 2.\" Copyright (c) 1997 3.\" Kazutaka YOKOTA <yokota@zodiac.mech.utsunomiya-u.ac.jp> 4.\" All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer as 11.\" the first lines of this file unmodified. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26.\" 27.\" $Id: psm.4,v 1.15 1999/02/07 05:40:14 yokota Exp $ 28.\" 29.Dd January 30, 1999 30.Dt PSM 4 i386 31.Os FreeBSD 32.Sh NAME 33.Nm psm 34.Nd 35PS/2 mouse style pointing device driver 36.Sh SYNOPSIS 37.Cd "options" \&"PSM_HOOKAPM\&" 38.Cd "options" \&"PSM_RESETAFTERSUSPEND\&" 39.Cd "options" \&"KBD_RESETDELAY=N\&" 40.Cd "options" \&"KBD_MAXWAIT=N\&" 41.Cd "options" \&"PSM_DEBUG=N\&" 42.Cd "options" \&"KBDIO_DEBUG=N\&" 43.Cd "device psm0 at atkbdc? irq 12" 44.Sh DESCRIPTION 45The 46.Nm 47driver provides support for the PS/2 mouse style pointing device. 48Currently there can be only one 49.Nm 50device node in the system. 51As the PS/2 mouse port is located 52at the auxiliary port of the keyboard controller, 53the keyboard controller driver, 54.Nm atkbdc , 55must also be configured in the kernel. 56Note that there is currently no provision of changing the 57.Em irq 58number. 59.Pp 60Basic PS/2 style pointing device has two or three buttons. 61Some devices may have a roller or a wheel and/or additional buttons. 62.Ss Device Resolution 63The PS/2 style pointing device usually has several grades of resolution, 64that is, sensitivity of movement. They are typically 25, 50, 100 and 200 65pulse per inch. Some devices may have finer resolution. 66The current resolution can be changed at runtime. The 67.Nm 68driver allows the user to initially set the resolution 69via the driver flag 70.Pq see Sx DRIVER CONFIGURATION 71or change it later via the 72.Xr ioctl 2 73command 74.Dv MOUSE_SETMODE 75.Pq see Sx IOCTLS . 76.Ss Report Rate 77Frequency, or report rate, at which the device sends movement 78and button state reports to the host system is also configurable. 79The PS/2 style pointing device typically supports 10, 20, 40, 60, 80, 100 80and 200 reports per second. 8160 or 100 appears to be the default value for many devices. 82Note that when there is no movement and no button has changed its state, 83the device won't send anything to the host system. 84The report rate can be changed via an ioctl call. 85.Ss Operation Levels 86The 87.Nm 88driver has three levels of operation. 89The current operation level can be set via an ioctl call. 90.Pp 91At the level zero the basic support is provided; the device driver will report 92horizontal and vertical movement of the attached device 93and state of up to three buttons. 94The movement and status are encoded in a series of fixed-length data packets 95.Pq see Sx Data Packet Format . 96This is the default level of operation and the driver is initially 97at this level when opened by the user program. 98.Pp 99The operation level one, the `extended' level, supports a roller (or wheel), 100if any, and up to 11 buttons. 101The movement of the roller is reported as movement along the Z axis. 1028 byte data packets are sent to the user program at this level. 103.Pp 104At the operation level two, data from the pointing device is passed to the 105user program as is. 106Modern PS/2 type pointing devices often use proprietary data format. 107Therefore, the user program is expected to have 108intimate knowledge about the format from a particular device when operating 109the driver at this level. 110This level is called `native' level. 111.Ss Data Packet Format 112Data packets read from the 113.Nm 114driver are formatted differently at each operation level. 115.Pp 116A data packet from the PS/2 mouse style pointing device 117is three bytes long at the operation level zero: 118.Pp 119.Bl -tag -width Byte_1 -compact 120.It Byte 1 121.Bl -tag -width bit_7 -compact 122.It bit 7 123One indicates overflow in the vertical movement count. 124.It bit 6 125One indicates overflow in the horizontal movement count. 126.It bit 5 127Set if the vertical movement count is negative. 128.It bit 4 129Set if the horizontal movement count is negative. 130.It bit 3 131Always one. 132.\" The ALPS GlidePoint clears this bit when the user `taps' the surface of 133.\" the pad, otherwise the bit is set. 134.\" Most, if not all, other devices always set this bit. 135.It bit 2 136Middle button status; set if pressed. For devices without the middle 137button, this bit is always zero. 138.It bit 1 139Right button status; set if pressed. 140.It bit 0 141Left button status; set if pressed. 142.El 143.It Byte 2 144Horizontal movement count in two's compliment; 145-256 through 255. 146Note that the sign bit is in the first byte. 147.It Byte 3 148Vertical movement count in two's compliment; 149-256 through 255. 150Note that the sign bit is in the first byte. 151.El 152.Pp 153At the level one, a data packet is encoded 154in the standard format 155.Dv MOUSE_PROTO_SYSMOUSE 156as defined in 157.Xr mouse 4 . 158.Pp 159At the level two, native level, there is no standard on the size and format 160of the data packet. 161.Ss Acceleration 162The 163.Nm 164driver can somewhat `accelerate' the movement of the pointing device. 165The faster you move the device, the further the pointer 166travels on the screen. 167The driver has an internal variable which governs the effect of 168the acceleration. Its value can be modified via the driver flag 169or via an ioctl call. 170.Ss Device Number 171The minor device number of the 172.Nm 173is made up of: 174.Bd -literal -offset indent 175minor = (`unit' << 1) | `non-blocking' 176.Ed 177.Pp 178where `unit' is the device number (usually 0) and the `non-blocking' bit 179is set to indicate ``don't block waiting for mouse input, 180return immediately''. 181The `non-blocking' bit should be set for \fIXFree86\fP, 182therefore the minor device number usually used for \fIXFree86\fP is 1. 183See 184.Sx FILES 185for device node names. 186.Sh DRIVER CONFIGURATION 187.Ss Kernel Configuration Options 188There are following kernel configuration options to control the 189.Nm 190driver. 191They may be set in the kernel configuration file 192.Pq see Xr config 8 . 193.Bl -tag -width MOUSE 194.It Em PSM_HOOKAPM 195The built-in PS/2 pointing device of some laptop computers is somehow 196not operable immediately after the system `resumes' from 197the power saving mode, 198though it will eventually become available. 199There are reports that 200stimulating the device by performing I/O will help 201waking up the device quickly. This option will add a piece of code 202to the 203.Nm 204driver to hook 205the APM `resume' event and exercise some harmless I/O operations to the 206device. 207.It Em PSM_RESETAFTERSUSPEND 208This option adds more drastic action for the above problem. 209It will make the 210.Nm 211driver to reset the pointing device after the APM resume event. 212It has no effect unless the 213.Em PSM_HOOKAPM 214option is enabled as well. 215.It Em KBD_RESETDELAY=X, KBD_MAXWAIT=Y 216The 217.Nm 218driver will attempt to reset the pointing device during the boot process. 219It sometimes takes a long while before the device will respond after 220reset. These options control how long the driver should wait before 221it eventually gives up waiting. The driver will wait 222.Fa X 223* 224.Fa Y 225msecs at most. If the driver seems unable to detect your pointing 226device, you may want to increase these values. The default values are 227200 msec for 228.Fa X 229and 5 230for 231.Fa Y . 232.It Em PSM_DEBUG=N, KBDIO_DEBUG=N 233Sets the debug level to 234.Fa N . 235The default debug level is zero. See 236.Sx DIAGNOSTICS 237for debug logging. 238.El 239.Ss Driver Flags 240The 241.Nm 242driver accepts the following driver flags. Set them in the 243kernel configuration file or in the User Configuration Menu at 244the boot time 245.Pq see Xr boot 8 . 246.Pp 247.Bl -tag -width MOUSE 248.It bit 0..3 RESOLUTION 249This flag specifies the resolution of the pointing device. 250It must be zero through four. The greater the value 251is, the finer resolution the device will select. 252Actual resolution selected by this field varies according to the model 253of the device. Typical resolutions are: 254.Pp 255.Bl -tag -width 0_(medium_high)__ -compact 256.It Em 1 (low) 25725 pulse per inch (ppi) 258.It Em 2 (medium low) 25950 ppi 260.It Em 3 (medium high) 261100 ppi 262.It Em 4 (high) 263200 ppi 264.El 265.Pp 266Leaving this flag zero will selects the default resolution for the 267device (whatever it is). 268.It bit 4..7 ACCELERATION 269This flag controls the amount of acceleration effect. 270The smaller the value of this flag is, more sensitive the movement becomes. 271The minimum value allowed, thus the value for the most sensitive setting, 272is one. Setting this flag to zero will completely disables the 273acceleration effect. 274.It bit 8 NOCHECKSYNC 275The 276.Nm 277driver tries to detect the first byte of the data packet by checking 278the bit pattern of that byte. Although this method should work with most 279PS/2 pointing devices, it may interfere with some devices which are not 280so compatible with known devices. 281If you think your pointing device is not functioning as expected, 282and the kernel frequently prints the following message to the console, 283.Bd -literal -offset indent 284psmintr: out of sync (xxxx != yyyy). 285.Ed 286.Pp 287set this flag to disable synchronization check and see if it helps. 288.It bit 9 NOIDPROBE 289The 290.Nm 291driver will not try to identify the model of the pointing device and 292will not carry out model-specific initialization. 293The device should always act like a standard PS/2 mouse without such 294initialization. 295Extra features, such as wheels and additional buttons, won't be 296recognized by the 297.Nm 298driver. 299.It bit 10 NORESET 300When this flag is set, the 301.Nm 302driver won't reset the pointing device when initializing the device. 303If the FreeBSD kernel 304is started after another OS has run, the pointing device will inherit 305settings from the previous OS. 306However, because there is no way for the 307.Nm 308driver to know the settings, the device and the driver may not 309work correctly. 310The flag should never be necessary under normal circumstances. 311.It bit 11 FORCETAP 312Some pad devices report as if the fourth button is pressed 313when the user `taps' the surface of the device (see 314.Sx CAVEATS ) . 315This flag will make the 316.Nm 317driver assume that the device behaves this way. 318Without the flag, the driver will assume this behavior 319for ALPS GlidePoint models only. 320.It bit 12 IGNOREPORTERROR 321This flag makes 322.Nm 323driver ignore certain error conditions when probing the PS/2 mouse port. 324It should never be necessary under normal circumstances. 325.El 326.Sh IOCTLS 327There are a few 328.Xr ioctl 2 329commands for mouse drivers. 330These commands and related structures and constants are defined in 331.Ao Pa machine/mouse.h Ac . 332General description of the commands is given in 333.Xr mouse 4 . 334This section explains the features specific to the 335.Nm 336driver. 337.Pp 338.Bl -tag -width MOUSE -compact 339.It Dv MOUSE_GETLEVEL Ar int *level 340.It Dv MOUSE_SETLEVEL Ar int *level 341These commands manipulate the operation level of the 342.Nm 343driver. 344.Pp 345.It Dv MOUSE_GETHWINFO Ar mousehw_t *hw 346Returns the hardware information of the attached device in the following 347structure. 348.Bd -literal 349typedef struct mousehw { 350 int buttons; /* number of buttons */ 351 int iftype; /* I/F type */ 352 int type; /* mouse/track ball/pad... */ 353 int model; /* I/F dependent model ID */ 354 int hwid; /* I/F dependent hardware ID */ 355} mousehw_t; 356.Ed 357.Pp 358The 359.Dv buttons 360field holds the number of buttons on the device. 361The 362.Nm 363driver currently can detect the 3 button mouse from Logitech and report 364accordingly. 365The 3 button mouse from the other manufacturer may or may not be 366reported correctly. However, it will not affect the operation of 367the driver. 368.Pp 369The 370.Dv iftype 371is always 372.Dv MOUSE_IF_PS2 . 373.Pp 374The 375.Dv type 376tells the device type: 377.Dv MOUSE_MOUSE , 378.Dv MOUSE_TRACKBALL , 379.Dv MOUSE_STICK , 380.Dv MOUSE_PAD , 381or 382.Dv MOUSE_UNKNOWN . 383The user should not heavily rely on this field, as the 384driver may not always, in fact it is very rarely able to, identify 385the device type. 386.Pp 387The 388.Dv model 389is always 390.Dv MOUSE_MODEL_GENERIC 391at the operation level 0. 392It may be 393.Dv MOUSE_MODEL_GENERIC 394or one of 395.Dv MOUSE_MODEL_XXX 396constants at higher operation levels. 397Again the 398.Nm 399driver may or may not set an appropriate value in this field. 400.Pp 401The 402.Dv hwid 403is the ID value returned by the device. 404Known IDs include: 405.Pp 406.Bl -tag -width 0__ -compact 407.It Em 0 408Mouse (Microsoft, Logitech and many other manufacturers) 409.It Em 2 410Microsoft Ballpoint mouse 411.It Em 3 412Microsoft IntelliMouse 413.El 414.Pp 415.It Dv MOUSE_GETMODE Ar mousemode_t *mode 416The command gets the current operation parameters of the mouse 417driver. 418.Bd -literal 419typedef struct mousemode { 420 int protocol; /* MOUSE_PROTO_XXX */ 421 int rate; /* report rate (per sec), -1 if unknown */ 422 int resolution; /* MOUSE_RES_XXX, -1 if unknown */ 423 int accelfactor; /* acceleration factor */ 424 int level; /* driver operation level */ 425 int packetsize; /* the length of the data packet */ 426 unsigned char syncmask[2]; /* sync. bits */ 427} mousemode_t; 428.Ed 429.Pp 430The 431.Dv protocol 432is 433.Dv MOUSE_PROTO_PS2 434at the operation level zero and two. 435.Dv MOUSE_PROTO_SYSMOUSE 436at the operation level one. 437.Pp 438The 439.Dv rate 440is the status report rate (reports/sec) at which the device will send 441movement report to the host computer. 442Typical supported values are 10, 20, 40, 60, 80, 100 and 200. 443Some mice may accept other arbitrary values too. 444.Pp 445The 446.Dv resolution 447of the pointing device must be one of 448.Dv MOUSE_RES_XXX 449constants or a positive value. The greater the value 450is, the finer resolution the mouse will select. 451Actual resolution selected by the 452.Dv MOUSE_RES_XXX 453constant varies according to the model of mouse. Typical resolutions are: 454.Pp 455.Bl -tag -width MOUSE_RES_MEDIUMHIGH__ -compact 456.It Dv MOUSE_RES_LOW 45725 ppi 458.It Dv MOUSE_RES_MEDIUMLOW 45950 ppi 460.It Dv MOUSE_RES_MEDIUMHIGH 461100 ppi 462.It Dv MOUSE_RES_HIGH 463200 ppi 464.El 465.Pp 466The 467.Dv accelfactor 468field holds a value to control acceleration feature 469.Pq see Sx Acceleration . 470It must be zero or greater. If it is zero, acceleration is disabled. 471.Pp 472The 473.Dv packetsize 474field specifies the length of the data packet. It depends on the 475operation level and the model of the pointing device. 476.Pp 477.Bl -tag -width level_0__ -compact 478.It Em level 0 4793 bytes 480.It Em level 1 4818 bytes 482.It Em level 2 483Depends on the model of the device 484.El 485.Pp 486The array 487.Dv syncmask 488holds a bit mask and pattern to detect the first byte of the 489data packet. 490.Dv syncmask[0] 491is the bit mask to be ANDed with a byte. If the result is equal to 492.Dv syncmask[1] , 493the byte is likely to be the first byte of the data packet. 494Note that this detection method is not 100% reliable, 495thus, should be taken only as an advisory measure. 496.Pp 497.It Dv MOUSE_SETMODE Ar mousemode_t *mode 498The command changes the current operation parameters of the mouse driver 499as specified in 500.Ar mode . 501Only 502.Dv rate , 503.Dv resolution , 504.Dv level 505and 506.Dv accelfactor 507may be modifiable. Setting values in the other field does not generate 508error and has no effect. 509.Pp 510If you do not want to change the current setting of a field, put -1 511there. 512You may also put zero in 513.Dv resolution 514and 515.Dv rate , 516and the default value for the fields will be selected. 517.\" .Pp 518.\" .It Dv MOUSE_GETVARS Ar mousevar_t *vars 519.\" .It Dv MOUSE_SETVARS Ar mousevar_t *vars 520.\" These commands are not supported by the 521.\" .Nm 522.\" driver. 523.Pp 524.It Dv MOUSE_READDATA Ar mousedata_t *data 525.\" The command reads the raw data from the device. 526.\" .Bd -literal 527.\" typedef struct mousedata { 528.\" int len; /* # of data in the buffer */ 529.\" int buf[16]; /* data buffer */ 530.\" } mousedata_t; 531.\" .Ed 532.\" .Pp 533.\" Upon returning to the user program, the driver will place the number 534.\" of valid data bytes in the buffer in the 535.\" .Dv len 536.\" field. 537.\" .Pp 538.It Dv MOUSE_READSTATE Ar mousedata_t *state 539.\" The command reads the hardware settings from the device. 540.\" Upon returning to the user program, the driver will place the number 541.\" of valid data bytes in the buffer in the 542.\" .Dv len 543.\" field. It is usually 3 bytes. 544.\" The buffer is formatted as follows: 545.\" .Pp 546.\" .Bl -tag -width Byte_1 -compact 547.\" .It Byte 1 548.\" .Bl -tag -width bit_6 -compact 549.\" .It bit 7 550.\" Reserved. 551.\" .It bit 6 552.\" 0 - stream mode, 1 - remote mode. 553.\" In the stream mode, the pointing device sends the device status 554.\" whenever its state changes. In the remote mode, the host computer 555.\" must request the status to be sent. 556.\" The 557.\" .Nm 558.\" driver puts the device in the stream mode. 559.\" .It bit 5 560.\" Set if the pointing device is currently enabled. Otherwise zero. 561.\" .It bit 4 562.\" 0 - 1:1 scaling, 1 - 2:1 scaling. 563.\" 1:1 scaling is the default. 564.\" .It bit 3 565.\" Reserved. 566.\" .It bit 2 567.\" Left button status; set if pressed. 568.\" .It bit 1 569.\" Middle button status; set if pressed. 570.\" .It bit 0 571.\" Right button status; set if pressed. 572.\" .El 573.\" .It Byte 2 574.\" .Bl -tag -width bit_6_0 -compact 575.\" .It bit 7 576.\" Reserved. 577.\" .It bit 6..0 578.\" Resolution code: zero through three. Actual resolution for 579.\" the resolution code varies from one device to another. 580.\" .El 581.\" .It Byte 3 582.\" The status report rate (reports/sec) at which the device will send 583.\" movement report to the host computer. 584.\" .El 585These commands are not currently supported by the 586.Nm 587driver. 588.Pp 589.It Dv MOUSE_GETSTATE Ar mousestatus_t *status 590The command returns the current state of buttons and 591movement counts as described in 592.Xr mouse 4 . 593.El 594.Sh FILES 595.Bl -tag -width /dev/npsm0 -compact 596.It Pa /dev/psm0 597`non-blocking' device node 598.It Pa /dev/bpsm0 599`blocking' device node under 600.Em devfs . 601.El 602.Sh EXAMPLE 603.Dl "options" \&"PSM_HOOKAPM\&" 604.Dl "device psm0 at atkbdc? irq 12" 605.Pp 606Add the 607.Nm 608driver to the kernel with the optional code to stimulate the pointing device 609after the `resume' event. 610.Pp 611.Dl "device psm0 at atkbdc? flags 0x024 irq 12" 612.Pp 613Set the device resolution high (4) and the acceleration factor to 2. 614.Sh DIAGNOSTICS 615.Pp 616At debug level 0, little information is logged except for the following 617line during boot process: 618.Bd -literal -offset indent 619psm0: device ID X 620.Ed 621.Pp 622where 623.Fa X 624the device ID code returned by the found pointing device. 625See 626.Dv MOUSE_GETINFO 627for known IDs. 628.Pp 629At debug level 1 more information will be logged 630while the driver probes the auxiliary port (mouse port). 631Messages are logged with the LOG_KERN facility at the LOG_DEBUG level 632.Pq see Xr syslogd 8 . 633.Bd -literal -offset indent 634psm0: current command byte:xxxx 635kbdio: TEST_AUX_PORT status:0000 636kbdio: RESET_AUX return code:00fa 637kbdio: RESET_AUX status:00aa 638kbdio: RESET_AUX ID:0000 639[...] 640psm: status 00 02 64 641psm0 irq 12 on isa 642psm0: model AAAA, device ID X, N buttons 643psm0: config:00000www, flags:0000uuuu, packet size:M 644psm0: syncmask:xx, syncbits:yy 645.Ed 646.Pp 647The first line shows the command byte value of the keyboard 648controller just before the auxiliary port is probed. 649It usually is 4D, 45, 47 or 65, depending on how the motherboard BIOS 650initialized the keyboard controller upon power-up. 651.Pp 652The second line shows the result of the keyboard controller's 653test on the auxiliary port interface, with zero indicating 654no error; note that some controllers report no error even if 655the port does not exist in the system, however. 656.Pp 657The third through fifth lines show the reset status of the pointing device. 658The functioning device should return the sequence of FA AA <ID>. 659The ID code is described above. 660.Pp 661The seventh line shows the current hardware settings. 662.\" See 663.\" .Dv MOUSE_READSTATE 664.\" for definitions. 665These bytes are formatted as follows: 666.Pp 667.Bl -tag -width Byte_1 -compact 668.It Byte 1 669.Bl -tag -width bit_6 -compact 670.It bit 7 671Reserved. 672.It bit 6 6730 - stream mode, 1 - remote mode. 674In the stream mode, the pointing device sends the device status 675whenever its state changes. In the remote mode, the host computer 676must request the status to be sent. 677The 678.Nm 679driver puts the device in the stream mode. 680.It bit 5 681Set if the pointing device is currently enabled. Otherwise zero. 682.It bit 4 6830 - 1:1 scaling, 1 - 2:1 scaling. 6841:1 scaling is the default. 685.It bit 3 686Reserved. 687.It bit 2 688Left button status; set if pressed. 689.It bit 1 690Middle button status; set if pressed. 691.It bit 0 692Right button status; set if pressed. 693.El 694.It Byte 2 695.Bl -tag -width bit_6_0 -compact 696.It bit 7 697Reserved. 698.It bit 6..0 699Resolution code: zero through three. Actual resolution for 700the resolution code varies from one device to another. 701.El 702.It Byte 3 703The status report rate (reports/sec) at which the device will send 704movement report to the host computer. 705.El 706.Pp 707Note that the pointing device will not be enabled until the 708.Nm 709driver is opened by the user program. 710.Pp 711The rest of the lines show the device ID code, the number of detected 712buttons and internal variables. 713.Pp 714At debug level 2, much more detailed information is logged. 715.Sh CAVEATS 716Many pad devices behave as if the first (left) button were pressed if 717the user `taps' the surface of the pad. 718In contrast, some ALPS GlidePoint pad models treat the tapping action 719as fourth button events. 720.Pp 721Some PS/2 mouse models from MouseSystems require to be put in the 722high resolution mode to work properly. Use the driver flag to 723set resolution. 724.Pp 725There is not a guaranteed way to re-synchronize with the first byte 726of the packet once we are out of synchronization with the data 727stream. However, if you are using the \fIXFree86\fP server and experiencing 728the problem, you may be able to make the X server synchronize with the mouse 729by switching away to a virtual terminal and getting back to the X server, 730unless the X server is accessing the mouse via 731.Xr moused 1 . 732Clicking any button without moving the mouse may also work. 733.Sh BUGS 734The ioctl command 735.Dv MOUSEIOCREAD 736has been removed. It was never functional anyway. 737.Sh SEE ALSO 738.Xr ioctl 2 , 739.Xr syslog 3 , 740.Xr atkbdc 4 , 741.Xr mouse 4 , 742.Xr mse 4 , 743.Xr sysmouse 4 , 744.Xr moused 8 , 745.Xr syslogd 8 746.\".Sh HISTORY 747.Sh AUTHORS 748The 749.Nm 750driver is based on the work done by quite a number of people, including 751.An Eric Forsberg , 752.An Sandi Donno , 753.An Rick Macklem , 754.An Andrew Herbert , 755.An Charles Hannum , 756.An Shoji Yuen 757and 758.An Kazutaka Yokota 759to name the few. 760.Pp 761This manual page was written by 762.An Kazutaka Yokota Aq yokota@FreeBSD.org . 763