Fixed bug 3583 - X11 touch device can be permanently lost

Volumetric

In X11 the SDL error "Unknown touch device" can occur after which the application stops recognizing touch events. For a kiosk-type application this results in a hang as far as the user is concerned. This is reproducible on HP Z220/Z230/Z240 workstations by swapping USB cables for a while and it also occurs with no physical changes, probably due to USB device power management. A workaround is to make SDL re-enumerate the touch devices like it does at startup. A patch is attached.
This commit is contained in:
Sam Lantinga 2017-02-11 11:14:48 -08:00
parent 06ccb71bcd
commit cf31ea1478
5 changed files with 22 additions and 2 deletions

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@ -25,6 +25,7 @@
#include "SDL_assert.h" #include "SDL_assert.h"
#include "SDL_events.h" #include "SDL_events.h"
#include "SDL_events_c.h" #include "SDL_events_c.h"
#include "../video/SDL_sysvideo.h"
static int SDL_num_touch = 0; static int SDL_num_touch = 0;
@ -48,7 +49,7 @@ SDL_TouchID
SDL_GetTouchDevice(int index) SDL_GetTouchDevice(int index)
{ {
if (index < 0 || index >= SDL_num_touch) { if (index < 0 || index >= SDL_num_touch) {
SDL_SetError("Unknown touch device"); SDL_SetError("Unknown touch device index %d", index);
return 0; return 0;
} }
return SDL_touchDevices[index]->id; return SDL_touchDevices[index]->id;
@ -74,7 +75,12 @@ SDL_GetTouch(SDL_TouchID id)
{ {
int index = SDL_GetTouchIndex(id); int index = SDL_GetTouchIndex(id);
if (index < 0 || index >= SDL_num_touch) { if (index < 0 || index >= SDL_num_touch) {
SDL_SetError("Unknown touch device"); if (SDL_GetVideoDevice()->ResetTouch != NULL) {
SDL_SetError("Unknown touch id %d, resetting", (int) id);
(SDL_GetVideoDevice()->ResetTouch)(SDL_GetVideoDevice());
} else {
SDL_SetError("Unknown touch device id %d, cannot reset", (int) id);
}
return NULL; return NULL;
} }
return SDL_touchDevices[index]; return SDL_touchDevices[index];

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@ -163,6 +163,11 @@ struct SDL_VideoDevice
*/ */
void (*VideoQuit) (_THIS); void (*VideoQuit) (_THIS);
/*
* Reinitialize the touch devices -- called if an unknown touch ID occurs.
*/
void (*ResetTouch) (_THIS);
/* * * */ /* * * */
/* /*
* Display functions * Display functions

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@ -42,6 +42,13 @@ X11_QuitTouch(_THIS)
SDL_TouchQuit(); SDL_TouchQuit();
} }
void
X11_ResetTouch(_THIS)
{
X11_QuitTouch(_this);
X11_InitTouch(_this);
}
#endif /* SDL_VIDEO_DRIVER_X11 */ #endif /* SDL_VIDEO_DRIVER_X11 */
/* vi: set ts=4 sw=4 expandtab: */ /* vi: set ts=4 sw=4 expandtab: */

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@ -25,6 +25,7 @@
extern void X11_InitTouch(_THIS); extern void X11_InitTouch(_THIS);
extern void X11_QuitTouch(_THIS); extern void X11_QuitTouch(_THIS);
extern void X11_ResetTouch(_THIS);
#endif /* SDL_x11touch_h_ */ #endif /* SDL_x11touch_h_ */

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@ -216,6 +216,7 @@ X11_CreateDevice(int devindex)
/* Set the function pointers */ /* Set the function pointers */
device->VideoInit = X11_VideoInit; device->VideoInit = X11_VideoInit;
device->VideoQuit = X11_VideoQuit; device->VideoQuit = X11_VideoQuit;
device->ResetTouch = X11_ResetTouch;
device->GetDisplayModes = X11_GetDisplayModes; device->GetDisplayModes = X11_GetDisplayModes;
device->GetDisplayBounds = X11_GetDisplayBounds; device->GetDisplayBounds = X11_GetDisplayBounds;
device->GetDisplayUsableBounds = X11_GetDisplayUsableBounds; device->GetDisplayUsableBounds = X11_GetDisplayUsableBounds;