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| author | Wolfram Sang <wsa@the-dreams.de> | 2014-06-17 14:36:41 +0200 |
|---|---|---|
| committer | Wolfram Sang <wsa@the-dreams.de> | 2014-06-17 14:37:31 +0200 |
| commit | f0b1f6442b5090fed3529cb39f3acf8c91693d3d (patch) | |
| tree | bc5f62b017a82161c9a7f892f464813f6efd5bf3 /drivers/net/ethernet/sfc/io.h | |
| parent | 4632a93f015caf6d7db4352f37aab74a39e60d7a (diff) | |
| parent | 7171511eaec5bf23fb06078f59784a3a0626b38f (diff) | |
| download | linux-f0b1f6442b5090fed3529cb39f3acf8c91693d3d.tar.bz2 | |
Merge tag 'v3.16-rc1' into i2c/for-next
Merge a stable base (Linux 3.16-rc1)
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers/net/ethernet/sfc/io.h')
| -rw-r--r-- | drivers/net/ethernet/sfc/io.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/net/ethernet/sfc/io.h b/drivers/net/ethernet/sfc/io.h index 4d3f119b67b3..afb94aa2c15e 100644 --- a/drivers/net/ethernet/sfc/io.h +++ b/drivers/net/ethernet/sfc/io.h @@ -66,10 +66,17 @@ #define EFX_USE_QWORD_IO 1 #endif +/* Hardware issue requires that only 64-bit naturally aligned writes + * are seen by hardware. Its not strictly necessary to restrict to + * x86_64 arch, but done for safety since unusual write combining behaviour + * can break PIO. + */ +#ifdef CONFIG_X86_64 /* PIO is a win only if write-combining is possible */ #ifdef ARCH_HAS_IOREMAP_WC #define EFX_USE_PIO 1 #endif +#endif #ifdef EFX_USE_QWORD_IO static inline void _efx_writeq(struct efx_nic *efx, __le64 value, |