The sampling of the GIC counter on Malta after observing a rising edge
of the RTC update flag differs slightly between the first and second
sample, with the first sample also calling gic_start_count(). The two
samples should really be taken as similarly as possible to get the most
accurate figure, so move the gic_start_count() call before detecting the
rising edge.
Signed-off-by: James Hogan <james.hogan@xxxxxxxxxx>
Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxx
---
arch/mips/mti-malta/malta-time.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)
diff --git a/arch/mips/mti-malta/malta-time.c b/arch/mips/mti-malta/malta-time.c
index b7bf721eabf5..2539687b77f6 100644
--- a/arch/mips/mti-malta/malta-time.c
+++ b/arch/mips/mti-malta/malta-time.c
@@ -81,16 +81,16 @@ static void __init estimate_frequencies(void)
local_irq_save(flags);
- /* Start counter exactly on falling edge of update flag. */
- while (CMOS_READ(RTC_REG_A) & RTC_UIP);
- while (!(CMOS_READ(RTC_REG_A) & RTC_UIP));
-
- /* Initialize counters. */
- start = read_c0_count();
- if (gic_present) {
+ if (gic_present)
gic_start_count();
+
+ /* Read counter exactly on falling edge of update flag. */
+ while (CMOS_READ(RTC_REG_A) & RTC_UIP);
+ while (!(CMOS_READ(RTC_REG_A) & RTC_UIP));
+
+ start = read_c0_count();
+ if (gic_present)
gicstart = gic_read_count();
- }
/* Read counter exactly on falling edge of update flag. */
while (CMOS_READ(RTC_REG_A) & RTC_UIP);
--
2.4.10
