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    SubjectRe: [PATCH v2 05/15] hwmon: mark const init data with __initconst instead of __initdata
    Hello Guenter,

    On Fri, Mar 30, 2012 at 08:54:42PM -0700, Guenter Roeck wrote:
    > On Fri, Mar 30, 2012 at 04:04:55PM -0400, Uwe Kleine-König wrote:
    > > As long as there is no other non-const variable marked __initdata in the
    > > same compilation unit it doesn't hurt. If there were one however
    > > compilation would fail with
    > >
    > > error: $variablename causes a section type conflict
    > >
    > > because a section containing const variables is marked read only and so
    > > cannot contain non-const variables.
    > >
    > > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
    > > Cc: Jean Delvare <khali@linux-fr.org>
    > > Cc: Guenter Roeck <guenter.roeck@ericsson.com>
    > > Cc: lm-sensors@lm-sensors.org
    > > ---
    > > changes since (implicit) v1:
    > > - drop wrong changes to drivers/hwmon/w83627hf.c
    > >
    > > drivers/hwmon/w83627ehf.c | 18 +++++++++---------
    > > 1 file changed, 9 insertions(+), 9 deletions(-)
    > >
    > > diff --git a/drivers/hwmon/w83627ehf.c b/drivers/hwmon/w83627ehf.c
    > > index a25350c..54922ed 100644
    > > --- a/drivers/hwmon/w83627ehf.c
    > > +++ b/drivers/hwmon/w83627ehf.c
    > > @@ -2619,15 +2619,15 @@ static struct platform_driver w83627ehf_driver = {
    > > static int __init w83627ehf_find(int sioaddr, unsigned short *addr,
    > > struct w83627ehf_sio_data *sio_data)
    > > {
    > > - static const char __initdata sio_name_W83627EHF[] = "W83627EHF";
    > > - static const char __initdata sio_name_W83627EHG[] = "W83627EHG";
    > > - static const char __initdata sio_name_W83627DHG[] = "W83627DHG";
    > > - static const char __initdata sio_name_W83627DHG_P[] = "W83627DHG-P";
    > > - static const char __initdata sio_name_W83627UHG[] = "W83627UHG";
    > > - static const char __initdata sio_name_W83667HG[] = "W83667HG";
    > > - static const char __initdata sio_name_W83667HG_B[] = "W83667HG-B";
    > > - static const char __initdata sio_name_NCT6775[] = "NCT6775F";
    > > - static const char __initdata sio_name_NCT6776[] = "NCT6776F";
    > > + static const char sio_name_W83627EHF[] __initconst = "W83627EHF";
    > > + static const char sio_name_W83627EHG[] __initconst = "W83627EHG";
    > > + static const char sio_name_W83627DHG[] __initconst = "W83627DHG";
    > > + static const char sio_name_W83627DHG_P[] __initconst = "W83627DHG-P";
    > > + static const char sio_name_W83627UHG[] __initconst = "W83627UHG";
    > > + static const char sio_name_W83667HG[] __initconst = "W83667HG";
    > > + static const char sio_name_W83667HG_B[] __initconst = "W83667HG-B";
    > > + static const char sio_name_NCT6775[] __initconst = "NCT6775F";
    > > + static const char sio_name_NCT6776[] __initconst = "NCT6776F";
    > >
    > Applied.
    >
    > Just wondering: Why not the following ?
    >
    > > + static const char __initconst sio_name_NCT6776[] = "NCT6776F";
    >
    > It does not make a difference in the generated code, and appears to be
    > less confusing, at least to me.
    hmm, I thought it does, maybe it's compiler dependant?! At least
    gcc-4.4.info tells:

    An attribute specifier list may appear immediately before the
    comma, `=' or semicolon terminating the declaration of an
    identifier other than a function definition.

    and include/linux/init.h has:

    You should insert __initdata between the variable name and equal
    sign followed by value [...].

    I seem to remember that placing the attribute at the wrong place for a
    function made gcc ignore it (or apply it so something unintended).

    Best regards
    Uwe

    --
    Pengutronix e.K. | Uwe Kleine-König |
    Industrial Linux Solutions | http://www.pengutronix.de/ |
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