[3/4] clocksource/vt8500: Use MIN_OSCR_DELTA from PXA

Commit Message

Roman Volkov Dec. 20, 2015, 10:28 p.m. UTC

From: Roman Volkov <[e-mail]>

Since vt8500 and PXA timers are identical, use MIN_OSCR_DELTA from PXA,
which is bigger than existing value. It is required to determine the
minimum delay which hardware can generate.

This commit fixes vt8500 breakage in Linux 4.2 introduced by
c6eb3f7 ('hrtimer: Get rid of hrtimer softirq')

Signed-off-by: Roman Volkov <[e-mail]>
---
 drivers/clocksource/vt8500_timer.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

Patch

diff --git a/drivers/clocksource/vt8500_timer.c b/drivers/clocksource/vt8500_timer.c
index f40ded8..7649852 100644
--- a/drivers/clocksource/vt8500_timer.c
+++ b/drivers/clocksource/vt8500_timer.c
@@ -51,6 +51,8 @@ 
 #define timer_readl(addr)	readl_relaxed(regbase + addr)
 #define timer_writel(v, addr)	writel_relaxed(v, regbase + addr)
 
+#define MIN_OSCR_DELTA		16
+
 static void __iomem *regbase;
 
 static cycle_t vt8500_timer_read(struct clocksource *cs)
@@ -78,7 +80,7 @@  static int vt8500_timer_set_next_event(unsigned long cycles,
 		cpu_relax();
 	timer_writel((unsigned long)alarm, TIMER_MATCH_VAL);
 
-	if ((signed)(alarm - clocksource.read(&clocksource)) <= 16)
+	if ((signed)(alarm - clocksource.read(&clocksource)) <= MIN_OSCR_DELTA)
 		return -ETIME;
 
 	timer_writel(1, TIMER_IER_VAL);
@@ -149,7 +151,7 @@  static void __init vt8500_timer_init(struct device_node *np)
 		pr_err("%s: setup_irq failed for %s\n", __func__,
 							clockevent.name);
 	clockevents_config_and_register(&clockevent, VT8500_TIMER_HZ,
-					4, 0xf0000000);
+					MIN_OSCR_DELTA * 2, 0xf0000000);
 }
 
 CLOCKSOURCE_OF_DECLARE(vt8500, "via,vt8500-timer", vt8500_timer_init);