From: David Howells Date: Tue, 6 Feb 2007 00:21:08 +0000 (-0800) Subject: IB/mthca: Work around gcc bug on sparc64 X-Git-Tag: v2.6.21-rc1~273^2^2~9 X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6bdd61d876e6eacea5c59230b6b2d988b22793e6;p=pandora-kernel.git IB/mthca: Work around gcc bug on sparc64 For some reason gcc-3.4.5 on sparc64 does: WARNING: "____ilog2_NaN" [drivers/infiniband/hw/mthca/ib_mthca.ko] undefined! Points to note: (1) The asm volatile flush/flushw are just markers for viewing what comes out in the assembly; removing them has no effect on the result. (2) Changing almost anything else in dwh__mthca_arbel_init_srq_context() or dwh__mthca_alloc_srq() causes the problem to go away. The compiler command line issued by the kernel build is: /opt/crosstool/gcc-3.4.5-glibc-2.3.6/sparc64-unknown-linux-gnu/bin/sparc64-unknown-linux-gnu-gcc -fno-strict-aliasing -fno-common -Os -m64 -mno-fpu -mcpu=ultrasparc -mcmodel=medlow -ffixed-g4 -ffixed-g5 -fcall-used-g7 -Wa,--undeclared-regs -pg -fno-omit-frame-pointer -fno-optimize-sibling-calls -fasynchronous-unwind-tables -g -c -o drivers/infiniband/hw/mthca/.tmp_mthca_srq.o drivers/infiniband/hw/mthca/mthca_srq.c This can be reduced to this whilst still retaining the problem: /opt/crosstool/gcc-3.4.5-glibc-2.3.6/sparc64-unknown-linux-gnu/bin/sparc64-unknown-linux-gnu-gcc -m64 -c -o drivers/infiniband/hw/mthca/mthca_srq.o drivers/infiniband/hw/mthca/mthca_srq.c -Os Removing -Os or changing it to -O or -O0 thru -O6 gets rid of the problem. This patch to the kernel code fixes the problem: Cc: "David S. Miller" Signed-off-by: Andrew Morton Signed-off-by: Roland Dreier --- Reading git-diff-tree failed