Files
linuxkit/kernel/patches-4.14.x-rt/0053-arm-at91-do-not-disable-enable-clocks-in-a-row.patch
Tiejun Chen a1d47ff766 update -rt to 4.14.53-rt34
Signed-off-by: Tiejun Chen <tiejun.china@gmail.com>
2018-07-06 14:02:07 +08:00

98 lines
3.0 KiB
Diff

From b6c2b5989660b182405f3934877171c0a96c4dcc Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Wed, 9 Mar 2016 10:51:06 +0100
Subject: [PATCH 053/418] arm: at91: do not disable/enable clocks in a row
Currently the driver will disable the clock and enable it one line later
if it is switching from periodic mode into one shot.
This can be avoided and causes a needless warning on -RT.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
drivers/clocksource/tcb_clksrc.c | 33 ++++++++++++++++++++++++++++----
1 file changed, 29 insertions(+), 4 deletions(-)
diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c
index 9de47d4d2d9e..4f45be268e52 100644
--- a/drivers/clocksource/tcb_clksrc.c
+++ b/drivers/clocksource/tcb_clksrc.c
@@ -126,6 +126,7 @@ static struct clocksource clksrc = {
struct tc_clkevt_device {
struct clock_event_device clkevt;
struct clk *clk;
+ bool clk_enabled;
void __iomem *regs;
};
@@ -143,6 +144,24 @@ static struct tc_clkevt_device *to_tc_clkevt(struct clock_event_device *clkevt)
*/
static u32 timer_clock;
+static void tc_clk_disable(struct clock_event_device *d)
+{
+ struct tc_clkevt_device *tcd = to_tc_clkevt(d);
+
+ clk_disable(tcd->clk);
+ tcd->clk_enabled = false;
+}
+
+static void tc_clk_enable(struct clock_event_device *d)
+{
+ struct tc_clkevt_device *tcd = to_tc_clkevt(d);
+
+ if (tcd->clk_enabled)
+ return;
+ clk_enable(tcd->clk);
+ tcd->clk_enabled = true;
+}
+
static int tc_shutdown(struct clock_event_device *d)
{
struct tc_clkevt_device *tcd = to_tc_clkevt(d);
@@ -150,8 +169,14 @@ static int tc_shutdown(struct clock_event_device *d)
writel(0xff, regs + ATMEL_TC_REG(2, IDR));
writel(ATMEL_TC_CLKDIS, regs + ATMEL_TC_REG(2, CCR));
+ return 0;
+}
+
+static int tc_shutdown_clk_off(struct clock_event_device *d)
+{
+ tc_shutdown(d);
if (!clockevent_state_detached(d))
- clk_disable(tcd->clk);
+ tc_clk_disable(d);
return 0;
}
@@ -164,7 +189,7 @@ static int tc_set_oneshot(struct clock_event_device *d)
if (clockevent_state_oneshot(d) || clockevent_state_periodic(d))
tc_shutdown(d);
- clk_enable(tcd->clk);
+ tc_clk_enable(d);
/* slow clock, count up to RC, then irq and stop */
writel(timer_clock | ATMEL_TC_CPCSTOP | ATMEL_TC_WAVE |
@@ -186,7 +211,7 @@ static int tc_set_periodic(struct clock_event_device *d)
/* By not making the gentime core emulate periodic mode on top
* of oneshot, we get lower overhead and improved accuracy.
*/
- clk_enable(tcd->clk);
+ tc_clk_enable(d);
/* slow clock, count up to RC, then irq and restart */
writel(timer_clock | ATMEL_TC_WAVE | ATMEL_TC_WAVESEL_UP_AUTO,
@@ -220,7 +245,7 @@ static struct tc_clkevt_device clkevt = {
/* Should be lower than at91rm9200's system timer */
.rating = 125,
.set_next_event = tc_next_event,
- .set_state_shutdown = tc_shutdown,
+ .set_state_shutdown = tc_shutdown_clk_off,
.set_state_periodic = tc_set_periodic,
.set_state_oneshot = tc_set_oneshot,
},
--
2.17.1