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    SubjectRe: Platform device id
    Hi Jean,

    On 9/7/07, Jean Delvare <> wrote:
    > Hi Greg, all,
    > While is a u32, platform_device_add() handles "-1" as
    > a special id value. This has potential for confusion and bugs. One such
    > bug was reported to me by David Brownell:
    > And since then I've found two other drivers affected (uartlite and
    > i2c-pxa).
    > Could we at least make an int so as to clear up the
    > confusion? I doubt that the id will ever be a large number anyway.
    > To go one step further, I am questioning the real value of this naming
    > exception for these "unique" platform devices. On top of the bugs I
    > mentioned above, it has potential for compatibility breakage: adding a
    > second device of the same type will rename the first one from "foo" to
    > "foo.0". It also requires specific checks in many individual platform
    > drivers. All this, as I understand it, for a purely aesthetic reason. I
    > don't think this is worth it. Would there be any objection to simply
    > getting rid of this exception and having all platform devices named
    > "foo.%d"?

    If a device has a <name>.<instance> scheme this implies possibility of
    having several instances of said device in a box. There are a few of
    platform devices that can only have one instance - for example i8042
    keyboard controller (the -1 special handling came from me because
    i80420 name was very confusing - there wasn't a dot separator in the
    name back then). Drivers that allow multiple devices should not
    attempt to use -1 for the very first instance - this should eliminate
    potential for error and special handling that you are talking about.

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      Last update: 2007-09-07 17:01    [W:0.029 / U:0.148 seconds]
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