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| author | Jayachandran C <jchandra@broadcom.com> | 2013-09-25 18:31:05 +0530 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2013-09-25 17:05:44 +0200 |
| commit | 55c25c2f14496badefd780a9f179442756216b67 (patch) | |
| tree | c29c3c8e3456328acdcd6f6d26079948eaad0429 /arch/mips/mm/dma-default.c | |
| parent | becee6b8c7b2b4adc9a3e0bec633abecd591b9ef (diff) | |
| download | linux-stable-55c25c2f14496badefd780a9f179442756216b67.tar.gz linux-stable-55c25c2f14496badefd780a9f179442756216b67.tar.bz2 linux-stable-55c25c2f14496badefd780a9f179442756216b67.zip | |
MIPS: mm: Move some checks out of 'for' loop in DMA operations
The check cpu_needs_post_dma_flush() in mips_dma_sync_sg_for_cpu() and
the check !plat_device_is_coherent() in mips_dma_sync_sg_for_device()
can be moved outside the for loop.
As a side effect, this also avoids a GCC bug that caused kernel compile
to fail with the error:
arch/mips/mm/dma-default.c: In function 'mips_dma_sync_sg_for_cpu':
arch/mips/mm/dma-default.c:316:1: internal compiler error: in add_insn_before, at emit-rtl.c:3852
This gcc failure is seen in Code Sourcery toolchains [e.g. gcc version
4.7.2 (Sourcery CodeBench Lite 2012.09-99)] after commit "MIPS: Optimize
current_cpu_type() for better code."
Signed-off-by: Jayachandran C <jchandra@broadcom.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/5907/
Reviewed-by: Markos Chandras <markos.chandras@imgtec.com>
Tested-by: Markos Chandras <markos.chandras@imgtec.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/mm/dma-default.c')
| -rw-r--r-- | arch/mips/mm/dma-default.c | 12 |
1 files changed, 4 insertions, 8 deletions
diff --git a/arch/mips/mm/dma-default.c b/arch/mips/mm/dma-default.c index f25a7e9f8cbc..5f8b95512580 100644 --- a/arch/mips/mm/dma-default.c +++ b/arch/mips/mm/dma-default.c @@ -308,12 +308,10 @@ static void mips_dma_sync_sg_for_cpu(struct device *dev, { int i; - /* Make sure that gcc doesn't leave the empty loop body. */ - for (i = 0; i < nelems; i++, sg++) { - if (cpu_needs_post_dma_flush(dev)) + if (cpu_needs_post_dma_flush(dev)) + for (i = 0; i < nelems; i++, sg++) __dma_sync(sg_page(sg), sg->offset, sg->length, direction); - } } static void mips_dma_sync_sg_for_device(struct device *dev, @@ -321,12 +319,10 @@ static void mips_dma_sync_sg_for_device(struct device *dev, { int i; - /* Make sure that gcc doesn't leave the empty loop body. */ - for (i = 0; i < nelems; i++, sg++) { - if (!plat_device_is_coherent(dev)) + if (!plat_device_is_coherent(dev)) + for (i = 0; i < nelems; i++, sg++) __dma_sync(sg_page(sg), sg->offset, sg->length, direction); - } } int mips_dma_mapping_error(struct device *dev, dma_addr_t dma_addr) |