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On Saturday 16 May 2009 19:14:17 pk wrote: |
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> Alan McKinnon wrote: |
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> > I'm not sure who's criticizing DeviceKit, but it isn't me :-) |
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> |
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> I guess it was me... :-) |
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> |
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> I find this thread interesting: |
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> http://lists.freedesktop.org/archives/xorg/2009-May/045561.html |
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> |
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> ...especially this: |
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> http://lists.freedesktop.org/archives/xorg/2009-May/045574.html |
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> |
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> Which seems like a much more sane way... to me. I don't know what BSD |
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> and other platforms use (instead of Udev) but I'm sure one could come up |
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> with a common API. |
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|
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Sometimes you have to make several horrendous errors to know what to not do |
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and thereby deduce what you should do - the only version 3 rule of thumb :-) |
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|
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From threads involving the hal maintainers I get the idea that the problem is |
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not so much the idea of hal, but rather it's implementation. And then there's |
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those fdi files... |
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|
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As I see it, at the bottom of the stack you have a kernel and at the top a |
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user space app (the X server will do for an example). Plug in a USB device |
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that the app can use, and the kernel needs to make a node in /dev for it if |
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it's not already there. The kernel should not be interrogating the device for |
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all possible info - that is expensive - and doesn't need to. It only needs |
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enough info to know what driver, major and minor numbers to use. X OTOH, can |
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successfully use much more info. If you have a 19 button mouse, it would like |
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to know and could even use it as a one-handed keyboard (extreme example). So |
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the current model uses udev as the interface to the kernel's nodes and HAL as |
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the interface to exactly what hardware you have. Seems pretty sane for the |
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most usual use case. At some point in the stack you will need the OS-dependant |
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part, my guess is the best place is between hal and udev. Only Linux uses |
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udev, but all OSes use something in that spot. And if not, they have static |
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nodes. |
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Meanwhile we have an acknowledged problem with hal - it's too complex, too |
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many things have been shoved into it that were never catered for in the |
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design, configuration is horrific - and the devs are having their usual |
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spirited debate about how best to approach a solution. This is perfectly |
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normal and perfectly healthy |
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|
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-- |
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alan dot mckinnon at gmail dot com |
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