Re: [PATCH] MIPS: DB1200: Set Config_OD for improved stability.
From: Sergei Shtylyov <hidden>
Date: 2011-02-10 18:16:29
Hello. Manuel Lauss wrote:
Setting Config_OD gets rid of a _LOT_ of spurious CPLD interrupts, but also decreases overall performance a bit.
Signed-off-by: Manuel Lauss <redacted>
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diff --git a/arch/mips/alchemy/devboards/db1200/setup.c b/arch/mips/alchemy/devboards/db1200/setup.c index 8876195..a3729c9 100644 --- a/arch/mips/alchemy/devboards/db1200/setup.c +++ b/arch/mips/alchemy/devboards/db1200/setup.c@@ -23,6 +23,13 @@ void __init board_setup(void) unsigned long freq0, clksrc, div, pfc; unsigned short whoami; + /* Set Config_OD (disable overlapping bus transaction):
The bit is called Config[OD] by other Alchemy code.
You just should add your Au1200 revision to au1xxx_cpu_needs_config_od() in
<asm/mach-au1x00.h> so that plat_mem_setup() automatically sets the bit (just
after it calls board_setup()); Au1200 rev. AC should have it set already...
+ * This gets rid of a _lot_ of spurious interrupts (especially + * wrt. IDE); but incurs ~10% performance hit in some + * cpu-bound applications. + */ + set_c0_config(1 << 19); + bcsr_init(DB1200_BCSR_PHYS_ADDR, DB1200_BCSR_PHYS_ADDR + DB1200_BCSR_HEXLED_OFS);
WBR, Sergei