lkml.org 
[lkml]   [2007]   [Feb]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: NAK new drivers without proper power management?
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 -- geert@linux-m68k.org

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
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2007-02-12 17:01    [W:0.184 / U:0.708 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site