Messages in this thread Patch in this message | | | Date | Wed, 24 Oct 2007 09:23:05 +0200 (CEST) | From | Geert Uytterhoeven <> | Subject | Re: const vs __{dev}initdata |
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On Tue, 23 Oct 2007, Jeff Garzik wrote: > Bartlomiej Zolnierkiewicz wrote: > > It seems that const cannot be (officialy) mixed with __{dev}initdata, > > > > include/linux/init.h: > > ... > > * > > * Also note, that this data cannot be "const". > > */ > > ... > > > > [ BTW Greg: this doesn't seem to be mentioned in LDD3. ] > > > > Any reason for this limitation (other than not having .init.rodata section > > and __const__{dev}initdata tag)? There are places where we really would > > like > > to have both, i.e. struct ide_port_info in drivers/ide. > > Thank you for asking this question... we really do need a solution for this. > > As you point out, there are many valid cases for both const and initdata.
Indeed. And sometimes it works, depending on the toolchain version. Cfr. the patch below which I couldn't submit due to this.
Patch monkeys: DO NOT APPLY ;-)
Subject: fbdev: move logo externs to header file
Move the external declarations for the various linux logo structures to <linux/linux_logo.h>. As a consequence, I had to change scripts/pnmtologo.c to add the appropriate `const' to the generated logo source code.
FIXME: This one is really tricky and cannot be applied! - gcc 3.4.6 20060404 (Red Hat 3.4.6-3) needs xxx_data[] and xxx_clut[] to be const too, else it complains about a section type conflict - ppu-gcc 4.1.0 20060304 (Red Hat 4.1.0-3) needs xxx_data[] and xxx_clut[] to be non-const, else it complains about a section type conflict Anyone with a suggestion how to fix this?
Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com> Acked-By: James Simmons <jsimmons@infradead.org> --- arch/powerpc/kernel/prom_init.c | 3 --- drivers/video/logo/logo.c | 13 ------------- include/linux/linux_logo.h | 13 +++++++++++++ scripts/pnmtologo.c | 2 +- 4 files changed, 14 insertions(+), 17 deletions(-)
--- a/arch/powerpc/kernel/prom_init.c +++ b/arch/powerpc/kernel/prom_init.c @@ -44,10 +44,7 @@ #include <asm/sections.h> #include <asm/machdep.h> -#ifdef CONFIG_LOGO_LINUX_CLUT224 #include <linux/linux_logo.h> -extern const struct linux_logo logo_linux_clut224; -#endif /* * Properties whose value is longer than this get excluded from our --- a/drivers/video/logo/logo.c +++ b/drivers/video/logo/logo.c @@ -21,19 +21,6 @@ #include <asm/bootinfo.h> #endif -extern const struct linux_logo logo_linux_mono; -extern const struct linux_logo logo_linux_vga16; -extern const struct linux_logo logo_linux_clut224; -extern const struct linux_logo logo_dec_clut224; -extern const struct linux_logo logo_mac_clut224; -extern const struct linux_logo logo_parisc_clut224; -extern const struct linux_logo logo_sgi_clut224; -extern const struct linux_logo logo_sun_clut224; -extern const struct linux_logo logo_superh_mono; -extern const struct linux_logo logo_superh_vga16; -extern const struct linux_logo logo_superh_clut224; -extern const struct linux_logo logo_m32r_clut224; - const struct linux_logo *fb_find_logo(int depth) { --- a/include/linux/linux_logo.h +++ b/include/linux/linux_logo.h @@ -32,6 +32,19 @@ struct linux_logo { const unsigned char *data; }; +extern const struct linux_logo logo_linux_mono; +extern const struct linux_logo logo_linux_vga16; +extern const struct linux_logo logo_linux_clut224; +extern const struct linux_logo logo_dec_clut224; +extern const struct linux_logo logo_mac_clut224; +extern const struct linux_logo logo_parisc_clut224; +extern const struct linux_logo logo_sgi_clut224; +extern const struct linux_logo logo_sun_clut224; +extern const struct linux_logo logo_superh_mono; +extern const struct linux_logo logo_superh_vga16; +extern const struct linux_logo logo_superh_clut224; +extern const struct linux_logo logo_m32r_clut224; + extern const struct linux_logo *fb_find_logo(int depth); #endif /* _LINUX_LINUX_LOGO_H */ --- a/scripts/pnmtologo.c +++ b/scripts/pnmtologo.c @@ -244,7 +244,7 @@ static void write_header(void) static void write_footer(void) { fputs("\n};\n\n", out); - fprintf(out, "struct linux_logo %s __initdata = {\n", logoname); + fprintf(out, "const struct linux_logo %s __initdata = {\n", logoname); fprintf(out, " .type\t= %s,\n", logo_types[logo_type]); fprintf(out, " .width\t= %d,\n", logo_width); fprintf(out, " .height\t= %d,\n", logo_height); With kind regards,
Geert Uytterhoeven Software Architect
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Phone: +32 (0)2 700 8453 Fax: +32 (0)2 700 8622 E-mail: Geert.Uytterhoeven@sonycom.com Internet: http://www.sony-europe.com/
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