Messages in this thread | | | From | Holger Schurig <> | Subject | Re: [PATCH] usb: generic calibration support | Date | Fri, 17 Nov 2006 09:12:29 +0100 |
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> sorry, but i have to give you a big NACK on that one:
Hehe, I actually anticipated this NACK :-)
> - no more modparam: it should be per-device sysfs attributes > (swap_xy is basically only for touchkitusb compatibility and > shoud be converted to per-device sysfs attribute as well. i > just never got to do it)
That would be okay for me.
> - calibration can be handled in userspace just fine
Yes it can, and that is the most convinging argument against my patch.
However, user-space calibration often sucks. For example, in X11 the calibration values are stored in /etc/X11/xorg.conf, so a calibration program has to parse & write that file. And I've seen binary-only-calibration programs from vendors use /etc/X11/XF86Config, which doesn't exist here. Anyway, once you've calibrated you have to restart X-Windows, so you need to terminate all running X applications just because of a silly re-calibration. Not nice.
A calibration at kernel level (may it be input level or driver level) doesn't have this problem. I can make the level persistent via udev, modules.conf or other means. Even when I have a frame-buffer based calibration utility, the calibration would be OK for X11 or GTK/DirectFB as well.
For me, this speaks against "Calibration is purely a user-space problem".
> - even for in-kernel it's in the wrong place. there are other > devices that report raw absolute data...so it would belong to > the input layer
Suppose I have a graphics tabled and a touchscreen connected at the same time. Can I distinguish this easily at the input layer level?
I can very easily distinguish this at the device driver level. After all, the individual calibration parameters are a property of this individual device. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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