On Tue, Oct 18, 2011 at 02:23:29PM +0200, Jan Kiszka wrote: > On 2011-10-18 14:05, Michael S. Tsirkin wrote: > > On Mon, Oct 17, 2011 at 09:15:47PM +0200, Jan Kiszka wrote: > >> On 2011-10-17 15:43, Michael S. Tsirkin wrote: > >>> On Mon, Oct 17, 2011 at 11:27:45AM +0200, Jan Kiszka wrote: > >>>> diff --git a/hw/msi.c b/hw/msi.c > >>>> index 3c7ebc3..9055155 100644 > >>>> --- a/hw/msi.c > >>>> +++ b/hw/msi.c > >>>> @@ -40,6 +40,14 @@ > >>>> /* Flag for interrupt controller to declare MSI/MSI-X support */ > >>>> bool msi_supported; > >>>> > >>>> +static void msi_unsupported(MSIMessage *msg) > >>>> +{ > >>>> + /* If we get here, the board failed to register a delivery handler. */ > >>>> + abort(); > >>>> +} > >>>> + > >>>> +void (*msi_deliver)(MSIMessage *msg) = msi_unsupported; > >>>> + > >>> > >>> How about we set this to NULL, and check it instead of the bool > >>> flag? > >>> > >> > >> Yeah. I will introduce > >> > >> bool msi_supported(void) > >> { > >> return msi_deliver != msi_unsupported; > >> } > >> > >> OK? > >> > >> Jan > >> > > > > Looks a bit weird ... > > NULL is a pretty standard value for an invalid pointer, isn't it? > > Save us the runtime check and is equally expressive and readable IMHO. > > Jan Do we need to check? NULL dereference leads to a crash just as surely... > -- > Siemens AG, Corporate Technology, CT T DE IT 1 > Corporate Competence Center Embedded Linux -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html