On Tuesday 30 October 2007 12:41, Ralf Baechle wrote:
> On Tue, Oct 30, 2007 at 11:34:29AM +0000, Denys Vlasenko wrote:
>
> > On Thursday 25 October 2007 22:41, Bartlomiej Zolnierkiewicz wrote:
> > > > -static const struct ide_port_info generic_chipsets[] __devinitdata = {
> > > > +static struct ide_port_info generic_chipsets[] __devinitdata = {
> > > > /* 0 */ DECLARE_GENERIC_PCI_DEV("Unknown", 0),
> > > >
> > > > { /* 1 */
> > >
> > > I would prefer to not remove const from generic_chipsets[] so:
> > >
> > > [PATCH] drivers/ide/pci/generic: fix build for CONFIG_HOTPLUG=n
> > >
> > > It turns out that const and __{dev}initdata cannot be mixed currently
> > > and that generic IDE PCI host driver is also affected by the same issue:
> > >
> > > On Thursday 25 October 2007, Ralf Baechle wrote:
> > > > CC drivers/ide/pci/generic.o
> > > > drivers/ide/pci/generic.c:52: error: __setup_str_ide_generic_all_on causes a
> > > > +section type conflict
> > >
> > > [ Also reported by Martijn Uffing <mp3project@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>. ]
> > >
> > > This patch workarounds the problem in a bit hackish way but without
> > > removing const from generic_chipsets[] (it adds const to __setup() so
> > > __setup_str_ide_generic_all becomes const).
> >
> > You wouldn't believe how much const data is not marked as const because
> > we don't have __constinitdata etc. Literally megabytes.
>
> The gain from marking it const is very little and once any non-const
> __initdata object is added to a compilation unit all other const declarations
> will have to be removed. Bad tradeoff.
We can intrduce new, ro sections or teach gcc that combining const objects into
non-ro sections is not a crime. I wonder why it currently disallows that.
(And it does it only _somethimes_, const pointers happily go into rw sections!)
--
vda
