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    SubjectRe: [PATCH 08/20] pinctrl: Assume map table entries can't have a NULL name field
    On Thu, Feb 23, 2012 at 08:39:58AM -0800, Stephen Warren wrote:
    > Dong Aisheng wrote at Wednesday, February 22, 2012 9:48 PM:
    > > On Wed, Feb 22, 2012 at 07:53:44PM -0800, Stephen Warren wrote:
    > ...
    > > > I'm hoping that we don't do this internal conversion. The rules I'd like are:
    > ...
    > > > * Every mapping table entry must include a non-NULL name field.
    > > >
    > > > * Every call to pinctrl_get()/pinctrl_lookup_state() must pass a non-NULL name
    > >
    > > This is a way.
    > >
    > > Before using this, i'm still wondering what big problems do you think for us to support
    > > a NULL map name?
    > > Because the name for devices do not have different state really does not make too much
    > > sense but extra overhead.
    >
    > If we disallow NULL names, it simplifies the code in the pinctrl core;
    > when registering mappings or right at the start of pinctrl_get() or
    > pinctrl_lookup_state(), we check if the name is NULL and if so error out.
    > Everywhere else can then assume name!=NULL, and hence not have special-
    > cases for name==NULL, e.g.:
    >
    > In debug code:
    > name ? name : "(unnamed)"
    > vs.:
    > name
    >
    > When matching mapping table entries:
    > match = !name ? !map->name : !strcmp(name, map->name)
    > vs.:
    > match = !strcmp(name, map->name)
    >
    > Similar for the body of pinctrl_lookup_state().
    >
    Yes, it does make thing simple.
    But i guess it's not the key point to not support NULL state name, right?

    > Equally, it's not possible to generate a mapping table entry with a NULL
    > name from device tree given the bindings we discussed, so disallowing them
    > everywhere keeps things consistent.
    >
    Yes, i'm wondering if we can change it a bit to support NULL name.
    I replied with my idea in another mail before this one.

    Regards
    Dong Aisheng



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