Messages in this thread Patch in this message | | | From | Andrey Smirnov <> | Subject | [PATCH v2 5/6] i.MX: system.c: Tweak prefetch settings for performance | Date | Tue, 14 Jun 2016 18:29:52 -0700 |
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Update Prefetch Control Register settings to match that of Freescale's Linux tree. As the commit e3addf1b773964eac7f797e8538c69481be4279c states (author Nitin Garg):
"... set Prefetch offset to 15, since it improves memcpy performance by 35%. Don't enable Incr double Linefill enable since it adversely affects memcpy performance by about 32MB/s and reads by 90MB/s. Tested with 4K to 16MB sized src and dst aligned buffer..."
Those results are also corroborated by our own testing.
Tested-by: Chris Healy <cphealy@gmail.com> Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com> --- arch/arm/mach-imx/system.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/arch/arm/mach-imx/system.c b/arch/arm/mach-imx/system.c index f0a9787..9ea01e3 100644 --- a/arch/arm/mach-imx/system.c +++ b/arch/arm/mach-imx/system.c @@ -111,8 +111,12 @@ void __init imx_init_l2cache(void) val = readl_relaxed(l2x0_base + L310_PREFETCH_CTRL); val |= L310_PREFETCH_CTRL_DBL_LINEFILL | L310_PREFETCH_CTRL_INSTR_PREFETCH | - L310_PREFETCH_CTRL_DATA_PREFETCH | - L310_PREFETCH_CTRL_DBL_LINEFILL_INCR; + L310_PREFETCH_CTRL_DATA_PREFETCH; + + /* Set perfetch offset to improve performance */ + val &= ~L310_PREFETCH_CTRL_OFFSET_MASK; + val |= 15; + writel_relaxed(val, l2x0_base + L310_PREFETCH_CTRL); } -- 2.5.5
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