Date: Tue, 16 Mar 2004 12:40:33 +0000

From: Alan Swanson Subject: [SDL] [PATCH] Linux joystick evdev axis count fix The event device configuration under Linux does not check the returned ioctl value when reading the axis information. This means extra undefined axes are returned. Note, in EV_HandleEvents, the default for case EV_ABS is to return any axis information which is fine as we have already checked for all valid absolute axes. No new axes should be returned after opening the device. (Unless, of course, the evdev allows closing and reassigning a new device while in use and I can't believe that happens.)
libsdl-org · May 16, 2004 · 9a12084 · 9a12084
1 parent 8b567d0
commit 9a12084
Showing 1 changed file with 2 additions and 1 deletion.
diff --git a/src/joystick/linux/SDL_sysjoystick.c b/src/joystick/linux/SDL_sysjoystick.c
@@ -594,7 +594,8 @@ static SDL_bool EV_ConfigJoystick(SDL_Joystick *joystick, int fd)
 			if ( test_bit(i, absbit) ) {
 				int values[5];
 
-				ioctl(fd, EVIOCGABS(i), values);
+				if ( ioctl(fd, EVIOCGABS(i), values) < 0 )
+					continue;
 #ifdef DEBUG_INPUT_EVENTS
 				printf("Joystick has absolute axis: %x\n", i);
 				printf("Values = { %d, %d, %d, %d, %d }\n",