Subject: Re: [PATCH 11/16] powerpc: vio_cmo: use dev_groups and not dev_attrs for bus_type

From: Greg Kroah-Hartman <[email-masked]>
Date: Sat, 10 Jun 2017 14:48:13 +0200

On Fri, Jun 09, 2017 at 09:23:10PM +1000, Michael Ellerman wrote:
> Greg Kroah-Hartman <[email-masked]> writes:
> 
> > On Fri, Jun 09, 2017 at 08:53:22AM +1000, Michael Ellerman wrote:
> >> Greg Kroah-Hartman <[email-masked]> writes:
> >> 
> >> > On Thu, Jun 08, 2017 at 11:12:10PM +1000, Michael Ellerman wrote:
> >> >> Greg Kroah-Hartman <[email-masked]> writes:
> >> >> 
> >> >> > The dev_attrs field has long been "depreciated" and is finally being
> >> >> > removed, so move the driver to use the "correct" dev_groups field
> >> >> > instead for struct bus_type.
> >> >> >
> >> >> > Cc: Benjamin Herrenschmidt <[email-masked]>
> >> >> > Cc: Paul Mackerras <[email-masked]>
> >> >> > Cc: Michael Ellerman <[email-masked]>
> >> >> > Cc: Vineet Gupta <[email-masked]>
> >> >> > Cc: Bart Van Assche <[email-masked]>
> >> >> > Cc: Robin Murphy <[email-masked]>
> >> >> > Cc: Joerg Roedel <[email-masked]>
> >> >> > Cc: Johan Hovold <[email-masked]>
> >> >> > Cc: Alexey Kardashevskiy <[email-masked]>
> >> >> > Cc: Krzysztof Kozlowski <[email-masked]>
> >> >> > Cc: <[email-masked]>
> >> >> > Signed-off-by: Greg Kroah-Hartman <[email-masked]>
> >> >> > ---
> >> >> >  arch/powerpc/platforms/pseries/vio.c | 37 +++++++++++++++++++++---------------
> >> >> >  1 file changed, 22 insertions(+), 15 deletions(-)
> >> >> 
> >> >> This one needed a bit more work to get building, the incremental diff is
> >> >> below. We need a forward declaration of name, devspec and modalias,
> >> >> which is a bit weird, but that's how the code is currently structured.
> >> >> And there's dev and bus attributes with the same name, so that needed an
> >> >> added "bus".
> >> >> 
> >> >> I booted v2 of patch 10 and this one and everything looks identical to
> >> >> upstream.
> >> >
> >> > Ah, many thanks, this was on my todo list to fix up today.
> >> >
> >> > But you renamed the sysfs files when you added "bus" to the function
> >> > names, are you sure you want to do that?  I don't mind, but if you
> >> > happen to have userspace tools that look at those files, they just broke
> >> > :(
> >> 
> >> Ugh crap, no that won't work.
> >> 
> >> I didn't see it when I tested because my machine doesn't have the CMO
> >> feature enabled.
> >> 
> >> I guess we have to open code some of the BUS_ATTR_RO() etc. so we can
> >> avoid the name clash.
> >
> > Or split it into multiple files, I've solved this that way in the past.
> > You shouldn't have to "open code" BUS_ATTR_RO().
> 
> It just requires one use of __ATTR(), which seems simpler than splitting
> the file in two.

Ah, yes, nice work, thanks.  If you wanted to be really "tricky", you
could just use __ATTR_RO() there, but I'll leave it as-is :)

Let's see what 0-day says about this version.

Many thanks for working on this, much appreciated.

greg k-h