Re: [patch 1/5] Staging: VME Framework for the Linux Kernel

From: Martyn Welch
Date: Tue Aug 11 2009 - 11:09:40 EST


Emilio G. Cota wrote:
Martyn Welch wrote:
Again: what part of the API I have defined forces the driver to know about the underlying bridge?

Let me answer with another question, maybe we get to understand
each other this way:

Could you please explain me what happens when 17 different drivers
want to control 17 different devices, each on a different slot,
same address modifier, only 1MB per device? Apply if necessary
to the tsi148 bridge.

Not the same question, but I'd agree - that would probably break the current model I have proposed. *However*, providing a resource management layer as you have proposed above the basic resource management my API provides would resolve that without added complexity in the bridge drivers themselves.

NB1. Any given driver knows nothing about the other devices
on the crate; each driver only knows about the address, am and
size of the mapping for the device it controls--user-space
provide this info on a per-driver basis.
Yes. I agree.
NB2. The mapping offsets configured through the cards' pins match
the information passed from user space to each of the cards.

Yes. If I understand you correctly, your saying that management of the devices in the VME address space is a system configuration issue.

Cheers,
E.
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