linux/include/linux/input.h

541 lines
19 KiB

Input: add detailed multi-touch finger data report protocol In order to utilize the full power of the new multi-touch devices, a way to report detailed finger data to user space is needed. This patch adds a multi-touch (MT) protocol which allows drivers to report details for an arbitrary number of fingers. The driver sends a SYN_MT_REPORT event via the input_mt_sync() function when a complete finger has been reported. In order to stay compatible with existing applications, the data reported in a finger packet must not be recognized as single-touch events. In addition, all finger data must bypass input filtering, since subsequent events of the same type refer to different fingers. A set of ABS_MT events with the desired properties are defined. The events are divided into categories, to allow for partial implementation. The minimum set consists of ABS_MT_TOUCH_MAJOR, ABS_MT_POSITION_X and ABS_MT_POSITION_Y, which allows for multiple fingers to be tracked. If the device supports it, the ABS_MT_WIDTH_MAJOR may be used to provide the size of the approaching finger. Anisotropy and direction may be specified with ABS_MT_TOUCH_MINOR, ABS_MT_WIDTH_MINOR and ABS_MT_ORIENTATION. Devices with more granular information may specify general shapes as blobs, i.e., as a sequence of rectangular shapes grouped together by a ABS_MT_BLOB_ID. Finally, the ABS_MT_TOOL_TYPE may be used to specify whether the touching tool is a finger or a pen. Signed-off-by: Henrik Rydberg <rydberg@euromail.se> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2009-04-28 07:47:33 -07:00
Input: uinput - avoid FF flush when destroying device Normally, when input device supporting force feedback effects is being destroyed, we try to "flush" currently playing effects, so that the physical device does not continue vibrating (or executing other effects). Unfortunately this does not work well for uinput as flushing of the effects deadlocks with the destroy action: - if device is being destroyed because the file descriptor is being closed, then there is noone to even service FF requests; - if device is being destroyed because userspace sent UI_DEV_DESTROY, while theoretically it could be possible to service FF requests, userspace is unlikely to do so (they'd need to make sure FF handling happens on a separate thread) even if kernel solves the issue with FF ioctls deadlocking with UI_DEV_DESTROY ioctl on udev->mutex. To avoid lockups like the one below, let's install a custom input device flush handler, and avoid trying to flush force feedback effects when we destroying the device, and instead rely on uinput to shut off the device properly. NMI watchdog: Watchdog detected hard LOCKUP on cpu 3 ... <<EOE>> [<ffffffff817a0307>] _raw_spin_lock_irqsave+0x37/0x40 [<ffffffff810e633d>] complete+0x1d/0x50 [<ffffffffa00ba08c>] uinput_request_done+0x3c/0x40 [uinput] [<ffffffffa00ba587>] uinput_request_submit.part.7+0x47/0xb0 [uinput] [<ffffffffa00bb62b>] uinput_dev_erase_effect+0x5b/0x76 [uinput] [<ffffffff815d91ad>] erase_effect+0xad/0xf0 [<ffffffff815d929d>] flush_effects+0x4d/0x90 [<ffffffff815d4cc0>] input_flush_device+0x40/0x60 [<ffffffff815daf1c>] evdev_cleanup+0xac/0xc0 [<ffffffff815daf5b>] evdev_disconnect+0x2b/0x60 [<ffffffff815d74ac>] __input_unregister_device+0xac/0x150 [<ffffffff815d75f7>] input_unregister_device+0x47/0x70 [<ffffffffa00bac45>] uinput_destroy_device+0xb5/0xc0 [uinput] [<ffffffffa00bb2de>] uinput_ioctl_handler.isra.9+0x65e/0x740 [uinput] [<ffffffff811231ab>] ? do_futex+0x12b/0xad0 [<ffffffffa00bb3f8>] uinput_ioctl+0x18/0x20 [uinput] [<ffffffff81241248>] do_vfs_ioctl+0x298/0x480 [<ffffffff81337553>] ? security_file_ioctl+0x43/0x60 [<ffffffff812414a9>] SyS_ioctl+0x79/0x90 [<ffffffff817a04ee>] entry_SYSCALL_64_fastpath+0x12/0x71 Reported-by: Rodrigo Rivas Costa <rodrigorivascosta@gmail.com> Reported-by: Clément VUCHENER <clement.vuchener@gmail.com> Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=193741 Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2017-09-01 17:13:43 -07:00