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 <manuel.lauss@xxxxxxxxxxxxxx>
[...]
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
