On Tue, Mar 04, 2008 at 06:55:49PM +0000, Peter Stokes wrote: > On Tuesday 04 March 2008 12:47:15 Ville Syrjälä wrote: > > On Sat, Feb 16, 2008 at 04:22:43PM +0000, Peter Stokes wrote: > > > The attached patch reconfigures the ati_remote2 driver to use > > > soft-autorepeat functionality and adds support for loadable key maps. > > > > Why was this submitted (and even accepted) without cc:ing me? > > > > I am very sorry, that was my fault, I should have cc'd you on the original > mail. Apology accepted. No harm done :) > > > I have reconfigure the driver to use the input system's built-in > > > autorepeat functionality as the device only appears to be able to produce > > > key repeat notifications at a fixed period. Switching to the software > > > autorepeat functionality provides more precise configuration of the > > > timings requested for repeat-delay and repeat-rate. > > > > The soft-autorepeat support should be split into a separate patch. I don't > > need such fast repeat but if it helps people I'm fine with it. > > > > My reasoning behind modifying the ati_remote2 driver to use the > soft-autorepeat implementation provided by the core input system was based > upon the following: > > * It states, in section 1.8 of "Documentation/input/input-programming.txt", > the following: > > 1.8 Key autorepeat > ~~~~~~~~~~~~~~~~~~ > > ... is simple. It is handled by the input.c module. Hardware autorepeat is > not used, because it's not present in many devices and even where it is > present, it is broken sometimes (at keyboards: Toshiba notebooks). To enable > autorepeat for your device, just set EV_REP in dev->evbit. All will be > handled by the input system. > > * Using soft-autorepeat provides a more accurate behavior (the initial delay > and the repeat rate behave as configured, as opposed to being rounded up to > the nearest multiple of the hardware's, apparently fixed, repeat > notifications (the hardware based repeat behavior also introduces timing > aliasing where the actual interval between successive repeats is > inconsistent). > > * Using soft-autorepeat makes the code in ati_remote2 slightly simpler. Right. I think the only downside is additional timer interrupts to handle the soft repeat. Probably the effect is too minimal to even consider. Dmitry did suggest using soft-repeat when I originally submitted the driver but I had no need for a faster repeat rate so I didn't change the driver to use it. > I am happy to produce a separate patch containing only the changes necessary > to switch the ati_remote2 driver over to use the soft-autorepeat behavior, if > that is indeed the consensus regarding the best approach to take. Yes, I'd like one patch per feature. > As for ensuring that the mouse buttons on this device do not have auto-repeat > behavior applied to them. I was very unsure of my proposed solution, as I > attempted to express in my initial email on the subject. It does however > strike me that if mouse buttons (and perhaps other button/key codes) should > not be auto-repeated then these codes should be excluded from the auto-repeat > implementation within the input core. Experimentation using my Microsoft > Internet Keyboard appeared to indicate that regular keys where repeated but > the extra buttons (things like launch email, launch web browser etc.) are not > (my investigations appeared to indicate, contrary to section 1.8 of the > documentation quoted above, that the repeat behavior was being performed by > the hardware and not by the input system's soft-autorepeat implementation). > This behavior appears to approximately coincide with the boundary described > by the KEY_MIN_INTERESTING define but I had no idea whether that was merely > coincidence. > > I am happy to implement multiple input devices, one for the mouse, and one for > the keyboard. If my understanding is correct, this would break backwards > compatibility as the two devices would be exposed by the evdev driver as two > separate event devices? > > If anyone can suggest the best approach to this problem I would be happy to > develop the necessary patches to implement the chosen solution. Ah, the backwards compatibility angle. It would be rude of us to break the behaviour like that. It probably wouldn't affect my typical use case (MPlayer + DirectFB) since I typically only use the keyboard part of the remote. But if there are people using both "components" of the remote they would have to change their configuration or in the worst case their code to handle such a change. Not nice at all. > > > As this device is exposed as a combined keyboard and mouse, this change > > > somewhat depends upon the suggested modification to the core > > > soft-autorepeat functionality as outlined in my previous post to the > > > linux-input mailing list (on 12th Feb 2008 entitled "Soft-autorepeat > > > functionality"), without that modification, the mouse buttons are > > > autorepeated :-( > > > > > > The loadable keymap support exposes the ability to map 5 separate > > > keycodes to each key (depending on which "mode" the remote control is > > > currently in). Additionally, I have attempted to ensure that the > > > scancodes used to map keycodes to the keys lie outside of the range > > > normally covered by regular keyboards so as to avoid requests to remap > > > the keys on the remote from being intercepted by a normal keyboard. > > > > I thought the idea of input devices was to reflect the hardware and the > > keymaps should be handled in userspace. If that's not the case then I think > > the keymap support code should not be inside the driver but instead inside > > the input core. We don't want such invasive changes in every driver do > > we? > > If I may explain my reasoning behind proposing the changes associated with the > loadable keymap support. I would welcome any feedback on my reasoning and > approach. > > My initial problem was that some of the keycodes mapped in the ati_remote2 > driver have values greater than 255 and as such I am unable to obtain the > input from pressing those keys in X windows (perhaps I'm missing some > required configuration of X windows somewhere?). Upon further investigation > into this I noticed that the input core provides a mechanism for altering the > keymap configuration but the ati_remote2 driver is not compatible with it. Ah, the dreaded X angle :) A bit of googling tells me that the X guys don't have a real fix coming any time soon. I suppose that is one reason for having some kind of keymap support in the input core. I personally don't care for it but there are apprently too few people who can digest the Xorg code so I suppose it has a compelling reason for existence. > Initially I simply modified the ati_remote2 to use the mechanism provided by > the input core. Having done that, it occurred to me that the mode buttons of > of the remote could be employed to effectively provide five sets of key > mappings and I thought that this might be of some use to someone somewhere... > > I appreciate that the implementation I have suggested is probably not in line > with the original intended functionality of the loadable keymap support in > the input system. But it does get round my issue with X windows.... > > It also occurred to me that perhaps the multiple-keyboards should be exposed > as separate input devices, but again, if my understanding is correct, that > would break backwards compatibility. > > Any suggestions on better approaches would certainly be greatfully relieved. I think you could implement the multiple keymaps thing rather trivially in user space by having a small daemon listening on the event device and loading a new keymap when a mode key is pressed. That would limit the changes to the driver, and it would not require any kernel changes when if you would need to adapt it to a device that uses a different driver. I think the only problem is the grab thingy. I'm not sure if the Xorg evdev driver grabs the device, but if it does then the daemon wouldn't be able to see the events. DirectFB's input driver does grab the device to prevent events leaking to the console (ctrl-c combination was rather unpleasant without the grab). One solution would be a more light weight grab that would only prevent the console from receiving the events but would let other applications to see them. I remeber seeing some discussion around device grab in the past. I wonder if anything useful came of it... -- Ville Syrjälä syrjala@xxxxxx http://www.sci.fi/~syrjala/ -- 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
