Re: [MIPS] DEC: Fix modpost warning.

Re: [MIPS] DEC: Fix modpost warning.

[Maciej W. Rozycki]

On Tue, 10 Jul 2007, linux-mips@linux-mips.org wrote:

>   LD      vmlinux
>   SYSMAP  System.map
>   SYSMAP  .tmp_System.map
>   MODPOST vmlinux
> WARNING: drivers/built-in.o(.data+0x2480): Section mismatch: reference to .init.text: (between 'sercons' and 'ds_parms')
> 
> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
> 
> ---
> 
>  drivers/tc/zs.c |    6 +++---
>  1 files changed, 3 insertions(+), 3 deletions(-)

 It looks like a bogus warning -- I presume it comes from a reference from 
"sercons" to serial_console_setup() -- but the driver is going away, so I 
could not care less...

  Maciej

Re: [MIPS] DEC: Fix modpost warning.

[Ralf Baechle]

On Tue, Jul 10, 2007 at 02:07:21PM +0100, Maciej W. Rozycki wrote:
> From: "Maciej W. Rozycki" <macro@linux-mips.org>
> Date: Tue, 10 Jul 2007 14:07:21 +0100 (BST)
> To: linux-mips@linux-mips.org
> Subject: Re: [MIPS] DEC: Fix modpost warning.
> Content-Type: TEXT/PLAIN; charset=US-ASCII
> 
> On Tue, 10 Jul 2007, linux-mips@linux-mips.org wrote:
> 
> >   LD      vmlinux
> >   SYSMAP  System.map
> >   SYSMAP  .tmp_System.map
> >   MODPOST vmlinux
> > WARNING: drivers/built-in.o(.data+0x2480): Section mismatch: reference to .init.text: (between 'sercons' and 'ds_parms')
> > 
> > Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
> > 
> > ---
> > 
> >  drivers/tc/zs.c |    6 +++---
> >  1 files changed, 3 insertions(+), 3 deletions(-)
> 
>  It looks like a bogus warning -- I presume it comes from a reference from 
> "sercons" to serial_console_setup() -- but the driver is going away, so I 
> could not care less...

Yes, the root cause was the reference to serial_console_setup.  It's hard
to teach modpost that this reference is bogus so I fixed the driver instead.
Other console drivers had the same issue.

  Ralf

Re: [MIPS] DEC: Fix modpost warning.

[Atsushi Nemoto]

On Tue, 10 Jul 2007 14:04:09 +0100, Ralf Baechle <ralf@linux-mips.org> wrote:
> Yes, the root cause was the reference to serial_console_setup.  It's hard
> to teach modpost that this reference is bogus so I fixed the driver instead.
> Other console drivers had the same issue.

The modpost has "_console" name in its whitelist.  So minimum
workaround would be something like this:

--- a/drivers/tc/zs.c
+++ b/drivers/tc/zs.c
@@ -136,6 +136,7 @@ struct dec_serial *zs_chain;	/* list of all channels */
 struct tty_struct zs_ttys[NUM_CHANNELS];
 
 #ifdef CONFIG_SERIAL_DEC_CONSOLE
+#define sercons ser_console
 static struct console sercons;
 #endif
 #if defined(CONFIG_SERIAL_DEC_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) && \

Re: [MIPS] DEC: Fix modpost warning.

[Maciej W. Rozycki]

On Tue, 10 Jul 2007, Ralf Baechle wrote:

> >  It looks like a bogus warning -- I presume it comes from a reference from 
> > "sercons" to serial_console_setup() -- but the driver is going away, so I 
> > could not care less...
> 
> Yes, the root cause was the reference to serial_console_setup.  It's hard
> to teach modpost that this reference is bogus so I fixed the driver instead.
> Other console drivers had the same issue.

 I would not call this change a fix -- the cure is worse than the disease.

 We should maintain a table of references to ignore for modpost then.  It 
should be discarded together with other init data and given the number of 
such references it would be rather minuscule compared to code held in 
memory unnecessarily throughout the boot cycle of the system just to 
satisfy a debugging tool.  Which is a very useful one, no doubt, but 
please do not forget about the common sense.

  Maciej

Re: [MIPS] DEC: Fix modpost warning.

[Ralf Baechle]

On Tue, Jul 10, 2007 at 03:37:30PM +0100, Maciej W. Rozycki wrote:

> satisfy a debugging tool.  Which is a very useful one, no doubt, but 
> please do not forget about the common sense.

As usual common sense is prefered with patches attached ;-)

  Ralf