Is there any downside to letting hiddev to cover all devices, even those that are supported by the hid system? I should point out that with the current settings, the n-trig digitizers do in fact bind to both drivers. Its been a useful debugging tool. Jiri Kosina wrote: > On Wed, 20 May 2009, Stéphane Chatty wrote: > >> I just saw a message in the linux-input ml about a USB tablet that is >> not registered in the input layer. Someone proposed that there might be >> no useful application in the HID report descriptors. >> >> There is an other possibility: the IS_INPUT_APPLICATION in hid.h might >> fail to capture a legitimate application. I am currently working on a >> HID driver for a multitouch surface by Stantum that has application >> usage 0x000d0004 (Digitizer / Touchscreen), and I had to change >> IS_INPUT_APPLICATION to have it registered in the input layer. The >> N-Trig surface is registered only because it declares two application >> collections: a Pen and a Touchscreen. >> >> The comment that accompanies the definition of the macro looks very old. >> Is there another reason why the definition of input applications is so >> restrictive? I had in mind to add the range 0x000d0002-0x000d0006 at >> least. Is there any contraindication to this? > > Hi Stephane, > > we definitely want to extend the IS_INPUT_APPLICATION() macro to reflect > the current hardware -- the contants used in the macro are quite old > indeed. > > On the other hand we must be careful not to break any userspace drivers -- > because currently hiddev node (which userspace drivers use) is created > when the device has at least one application which is not recognized as > input application by IS_INPUT_APPLICATION macro. > > If we change semantics of this macro, it might happen that hiddev node > would stop appearing for certain devices, thus breaking backwards > compatibility for userspace drivers. > -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
