On Mon, 12 Feb 2007, Pavel Machek wrote:
> > > "If the device requires that, implement .suspend and .resume or at least
> >                                                                   ^^^^^^^^
> > > define .suspend that will always return -ENOSYS (then people will know 
> > > they
> >   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> > > have to unload the driver before the suspend).  Similarly, if you aren't 
> > > sure
> > > whether or not the device requires .suspend and .resume, define .suspend 
> > > that
> >                                                            
> > ^^^^^^^^^^^^^^^^^^^^
> > > will always return -ENOSYS."
> >   ^^^^^^^^^^^^^^^^^^^^^^^^^^^
> > Can't the upper layer just assume -ENOSYS if .resume/.suspend is NULL?
> > It's nicer if you don't have to implement dummy functions at all.
> 
> Unfortunately, drivers currently assume "NULL == nothing is needed",
> so we'd have t do big search & replace... 

Which means you also cannot easily keep track of which driver supports
suspend/resume and which doesn't, as there will always be drivers where a
missing suspend/resume function is correct.

Wouldn't it be more sensible to have

    .suspend = suspend_nothing_to_do

instead, and reserve NULL for `not yet implemented'?

Gr{oetje,eeting}s,

                                                Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [EMAIL PROTECTED]

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                                            -- Linus Torvalds
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