Messages in this thread | | | Date | Tue, 11 Aug 2009 17:38:24 +0100 | From | Martyn Welch <> | Subject | Re: [patch 1/5] Staging: VME Framework for the Linux Kernel |
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Emilio G. Cota wrote: > Martyn Welch wrote: > >>> It wouldn't break it, the model simply couldn't give you more >>> than 8 windows-->8 devices. >>> >>> >> Unless the devices we the same and the driver reused one window. >> > > No, we agreed on that devices should know *nothing* about windows. > > Don't think I did. :-)
I agreed that it would be impossible to assign sole use of 8 resources to 17 different drivers. I feel that there could be room and indeed a need for both approaches. It may be more efficient for a driver to use and move 1 window to position it's self over the registers of each of a number of compatible devices as required. Such a driver could exist side-by-side with drivers using your approach, that utilize a layer which removes such control. Whilst I understand you can assign a fairly sizable chunk of memory mapped IO for VME, this is not always the case. In situations where the available memory mapped IO is limited, placing a large window to cover 2 smaller windows with dead space in between them will not be an adequate solution either.
Martyn > E. >
-- Martyn Welch MEng MPhil MIET (Principal Software Engineer) T:+44(0)1327322748 GE Fanuc Intelligent Platforms Ltd, |Registered in England and Wales Tove Valley Business Park, Towcester, |(3828642) at 100 Barbirolli Square, Northants, NN12 6PF, UK T:+44(0)1327359444 |Manchester,M2 3AB VAT:GB 927559189
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