[U-Boot] [PATCH] nios2: zap dly_clks
Thomas Chou
thomas at wytron.com.tw
Wed Sep 9 07:09:51 CEST 2015
The dly_clks() in start.S is no use after switching to
generic timer. Remove it.
Signed-off-by: Thomas Chou <thomas at wytron.com.tw>
---
arch/nios2/cpu/start.S | 33 ---------------------------------
1 file changed, 33 deletions(-)
diff --git a/arch/nios2/cpu/start.S b/arch/nios2/cpu/start.S
index f80b4f3..e92f06e 100644
--- a/arch/nios2/cpu/start.S
+++ b/arch/nios2/cpu/start.S
@@ -175,39 +175,6 @@ relocate_code:
callr r8
ret
-/*
- * dly_clks -- Nios2 (like Nios1) doesn't have a timebase in
- * the core. For simple delay loops, we do our best by counting
- * instruction cycles.
- *
- * Instruction performance varies based on the core. For cores
- * with icache and static/dynamic branch prediction (II/f, II/s):
- *
- * Normal ALU (e.g. add, cmp, etc): 1 cycle
- * Branch (correctly predicted, taken): 2 cycles
- * Negative offset is predicted (II/s).
- *
- * For cores without icache and no branch prediction (II/e):
- *
- * Normal ALU (e.g. add, cmp, etc): 6 cycles
- * Branch (no prediction): 6 cycles
- *
- * For simplicity, if an instruction cache is implemented we
- * assume II/f or II/s. Otherwise, we use the II/e.
- *
- */
- .globl dly_clks
-
-dly_clks:
-
-#if (CONFIG_SYS_ICACHE_SIZE > 0)
- subi r4, r4, 3 /* 3 clocks/loop */
-#else
- subi r4, r4, 12 /* 12 clocks/loop */
-#endif
- bge r4, r0, dly_clks
- ret
-
.data
.globl version_string
--
2.1.4
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