On Wed, 19 Sep 2007, Andrew Morton wrote:
> > patch-mips-2.6.23-rc5-20070904-pmag-ba-err-2
> > diff -up --recursive --new-file
> > linux-mips-2.6.23-rc5-20070904.macro/drivers/video/pmag-ba-fb.c
> > linux-mips-2.6.23-rc5-20070904/drivers/video/pmag-ba-fb.c
> > --- linux-mips-2.6.23-rc5-20070904.macro/drivers/video/pmag-ba-fb.c
> > 2007-02-21 05:56:47.000000000 +0000
> > +++ linux-mips-2.6.23-rc5-20070904/drivers/video/pmag-ba-fb.c
> > 2007-09-18 10:56:51.000000000 +0000
> > @@ -147,16 +147,23 @@ static int __init pmagbafb_probe(struct
> > resource_size_t start, len;
> > struct fb_info *info;
> > struct pmagbafb_par *par;
> > + int err = 0;
> This initialisation to zero is not good.
> Because if some error-path code forgot to do `err = -EFOO' then probe()
> will return zero and the driver will leave things in half-initialised state
> and will then proceed as if things had succeeded. It will crash.
GCC used to complain: "`foo' might be used uninitialized..." and this is
the usual cure; let me see if this not the case anymore (I have 4.1.2).
> So it's better to leave this local uninitialised, because we really want to
> get that compiler warning if someone forgot to set the return value.
Yes of course, barring the issue mentioned. Note the message above is
not the same as: "`foo' is used uninitialized..." that would be reported
in the case which you are concerned of.
> I made that change, but am too stupid to be able to work out how to create
> a config which will let me compile this thing.
> akpm:/usr/src/25> grep PMAG arch/arm/configs/*
TURBOchannel is currently MIPS only:
$ grep PMAG arch/mips/configs/*
arch/mips/configs/decstation_defconfig:# CONFIG_FB_PMAG_AA is not set
Thanks for your review.