diff options
Diffstat (limited to 'target/linux/s3c24xx/patches-2.6.24/1300-fix-gcc-4.3-false-modulo-optimization.patch.patch')
| -rw-r--r-- | target/linux/s3c24xx/patches-2.6.24/1300-fix-gcc-4.3-false-modulo-optimization.patch.patch | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/target/linux/s3c24xx/patches-2.6.24/1300-fix-gcc-4.3-false-modulo-optimization.patch.patch b/target/linux/s3c24xx/patches-2.6.24/1300-fix-gcc-4.3-false-modulo-optimization.patch.patch new file mode 100644 index 0000000000..3ff0c07c18 --- /dev/null +++ b/target/linux/s3c24xx/patches-2.6.24/1300-fix-gcc-4.3-false-modulo-optimization.patch.patch @@ -0,0 +1,48 @@ +From f5b973489beb1a1239dfad53e3ad6e36ff7ee958 Mon Sep 17 00:00:00 2001 +From: Segher Boessenkool <segher@kernel.crashing.org> +Date: Thu, 9 Oct 2008 21:18:27 +0100 +Subject: [PATCH] fix-gcc-4.3-false-modulo-optimization.patch + +I tried to compile the current stable kernel +(a2ef813d2f439a3e9f377d33a2e5baad098afb7e) +and get the following errors: + +kernel/built-in.o: In function `timespec_add_ns': +/mnt/data/Freerunner/Gentoo/rootinstall/usr/src/linux/include/linux/time.h:174: +undefined reference to `__aeabi_uldivmod' +/mnt/data/Freerunner/Gentoo/rootinstall/usr/src/linux/include/linux/time.h:179: +undefined reference to `__aeabi_uldivmod' +/mnt/data/Freerunner/Gentoo/rootinstall/usr/src/linux/include/linux/time.h:174: +undefined reference to `__aeabi_uldivmod' +/mnt/data/Freerunner/Gentoo/rootinstall/usr/src/linux/include/linux/time.h:179: +undefined reference to `__aeabi_uldivmod' + +applying the following patch solved the problem: +-------- +Prevent gcc-4.3 form "optimizing" the while loop into a costly modulo operation. +Patch found at http://lkml.org/lkml/2008/2/22/464. + +Reported-by: Sven Rebhan <odinshorse@googlemail.com> +Signed-off-by: Segher Boessenkool <segher@kernel.crashing.org> +--- + include/linux/time.h | 4 ++++ + 1 files changed, 4 insertions(+), 0 deletions(-) + +diff --git a/include/linux/time.h b/include/linux/time.h +index b04136d..3e8fd9e 100644 +--- a/include/linux/time.h ++++ b/include/linux/time.h +@@ -173,6 +173,10 @@ static inline void timespec_add_ns(struct timespec *a, u64 ns) + { + ns += a->tv_nsec; + while(unlikely(ns >= NSEC_PER_SEC)) { ++ /* The following asm() prevents the compiler from ++ * optimising this loop into a modulo operation. */ ++ asm("" : "+r"(ns)); ++ + ns -= NSEC_PER_SEC; + a->tv_sec++; + } +-- +1.5.6.5 + |