| Message ID | 1411530284-28807-1-git-send-email-behanw@converseincode.com |
|---|---|
| State | Accepted |
| Commit | 49dd0dcfd76091989a746968b7403e038a1953bf |
| Headers | show |
On Tuesday 23 September 2014 20:44:44 Behan Webster wrote: > The ASM below does not compile with clang and is not the way that the mcr > command is used in other parts of the kernel. > > arch/arm/mach-vt8500/vt8500.c:72:11: error: invalid % escape in inline assembly string > asm("mcr%? p15, 0, %0, c7, c0, 4" : : "r" (0)); > ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~ > 1 error generated. > > There are other forms that are supported on different ARM instruction sets but > generally the kernel just uses mcr as it is supported in all ARM instruction > sets. Just for confirm: both forms are actually correct and we don't need this backported for stable, right? > Signed-off-by: Behan Webster <behanw@converseincode.com> > Reviewed-by: Mark Charlebois <charlebm@gmail.com> > Acked-by: Will Deacon <will.deacon@arm.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Tony, would you like to pick this one up and send it in a pull request to arm-soc, or should we apply it to fixes-non-critical directly? Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
On 09/24/14 02:16, Arnd Bergmann wrote: > On Tuesday 23 September 2014 20:44:44 Behan Webster wrote: >> The ASM below does not compile with clang and is not the way that the mcr >> command is used in other parts of the kernel. >> >> arch/arm/mach-vt8500/vt8500.c:72:11: error: invalid % escape in inline assembly string >> asm("mcr%? p15, 0, %0, c7, c0, 4" : : "r" (0)); >> ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~ >> 1 error generated. >> >> There are other forms that are supported on different ARM instruction sets but >> generally the kernel just uses mcr as it is supported in all ARM instruction >> sets. > Just for confirm: both forms are actually correct and we don't need this > backported for stable, right? My understanding is that the %? carries a condition code to the next instruction (which in this case is then ignored). So essentially in this situation both are equivalent. >> Signed-off-by: Behan Webster <behanw@converseincode.com> >> Reviewed-by: Mark Charlebois <charlebm@gmail.com> >> Acked-by: Will Deacon <will.deacon@arm.com> > Acked-by: Arnd Bergmann <arnd@arndb.de> > > Tony, would you like to pick this one up and send it in a pull request > to arm-soc, or should we apply it to fixes-non-critical directly? Thanks, Behan
On 24/09/14 21:16, Arnd Bergmann wrote: > On Tuesday 23 September 2014 20:44:44 Behan Webster wrote: >> The ASM below does not compile with clang and is not the way that the mcr >> command is used in other parts of the kernel. >> >> arch/arm/mach-vt8500/vt8500.c:72:11: error: invalid % escape in inline assembly string >> asm("mcr%? p15, 0, %0, c7, c0, 4" : : "r" (0)); >> ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~ >> 1 error generated. >> >> There are other forms that are supported on different ARM instruction sets but >> generally the kernel just uses mcr as it is supported in all ARM instruction >> sets. > Just for confirm: both forms are actually correct and we don't need this > backported for stable, right? > >> Signed-off-by: Behan Webster <behanw@converseincode.com> >> Reviewed-by: Mark Charlebois <charlebm@gmail.com> >> Acked-by: Will Deacon <will.deacon@arm.com> > Acked-by: Arnd Bergmann <arnd@arndb.de> > > Tony, would you like to pick this one up and send it in a pull request > to arm-soc, or should we apply it to fixes-non-critical directly? > > Arnd Arnd, You can apply it directly to fixes-non-critical if that's ok. Regards Tony Prisk
On Wednesday 24 September 2014, Tony Prisk wrote: > > Tony, would you like to pick this one up and send it in a pull request > > to arm-soc, or should we apply it to fixes-non-critical directly? > > > > Arnd > Arnd, > > You can apply it directly to fixes-non-critical if that's ok. Applied, thanks! Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
diff --git a/arch/arm/mach-vt8500/vt8500.c b/arch/arm/mach-vt8500/vt8500.c index 2da7be3..3bc0dc9 100644 --- a/arch/arm/mach-vt8500/vt8500.c +++ b/arch/arm/mach-vt8500/vt8500.c @@ -69,7 +69,7 @@ static void vt8500_power_off(void) { local_irq_disable(); writew(5, pmc_base + VT8500_HCR_REG); - asm("mcr%? p15, 0, %0, c7, c0, 4" : : "r" (0)); + asm("mcr p15, 0, %0, c7, c0, 4" : : "r" (0)); } static void __init vt8500_init(void)
The ASM below does not compile with clang and is not the way that the mcr command is used in other parts of the kernel. arch/arm/mach-vt8500/vt8500.c:72:11: error: invalid % escape in inline assembly string asm("mcr%? p15, 0, %0, c7, c0, 4" : : "r" (0)); ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~ 1 error generated. There are other forms that are supported on different ARM instruction sets but generally the kernel just uses mcr as it is supported in all ARM instruction sets. Signed-off-by: Behan Webster <behanw@converseincode.com> Reviewed-by: Mark Charlebois <charlebm@gmail.com> Acked-by: Will Deacon <will.deacon@arm.com> --- arch/arm/mach-vt8500/vt8500.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)