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-rw-r--r--arch/sh/lib/delay.c15
1 files changed, 13 insertions, 2 deletions
diff --git a/arch/sh/lib/delay.c b/arch/sh/lib/delay.c
index f3ddd2133e6..0901b2f14e1 100644
--- a/arch/sh/lib/delay.c
+++ b/arch/sh/lib/delay.c
@@ -10,6 +10,16 @@
void __delay(unsigned long loops)
{
__asm__ __volatile__(
+ /*
+ * ST40-300 appears to have an issue with this code,
+ * normally taking two cycles each loop, as with all
+ * other SH variants. If however the branch and the
+ * delay slot straddle an 8 byte boundary, this increases
+ * to 3 cycles.
+ * This align directive ensures this doesn't occur.
+ */
+ ".balign 8\n\t"
+
"tst %0, %0\n\t"
"1:\t"
"bf/s 1b\n\t"
@@ -21,13 +31,14 @@ void __delay(unsigned long loops)
inline void __const_udelay(unsigned long xloops)
{
+ xloops *= 4;
__asm__("dmulu.l %0, %2\n\t"
"sts mach, %0"
: "=r" (xloops)
: "0" (xloops),
- "r" (HZ * cpu_data[raw_smp_processor_id()].loops_per_jiffy)
+ "r" (cpu_data[raw_smp_processor_id()].loops_per_jiffy * (HZ/4))
: "macl", "mach");
- __delay(xloops);
+ __delay(++xloops);
}
void __udelay(unsigned long usecs)