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Subject[PATCH 02/25] clocksource: sh_cmt: Replace global spinlock with a per-device spinlock
Date
From: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

The global spinlock is used to protect the shared start/stop register.
Now that all CMT channels are handled by a single device instance, use a
per-device spinlock.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Tested-by: Simon Horman <horms+renesas@verge.net.au>
---
drivers/clocksource/sh_cmt.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/clocksource/sh_cmt.c b/drivers/clocksource/sh_cmt.c
index fcd38db..190c655 100644
--- a/drivers/clocksource/sh_cmt.c
+++ b/drivers/clocksource/sh_cmt.c
@@ -118,6 +118,8 @@ struct sh_cmt_device {
void __iomem *mapbase;
struct clk *clk;

+ raw_spinlock_t lock; /* Protect the shared start/stop register */
+
struct sh_cmt_channel *channels;
unsigned int num_channels;

@@ -299,14 +301,12 @@ static unsigned long sh_cmt_get_counter(struct sh_cmt_channel *ch,
return v2;
}

-static DEFINE_RAW_SPINLOCK(sh_cmt_lock);
-
static void sh_cmt_start_stop_ch(struct sh_cmt_channel *ch, int start)
{
unsigned long flags, value;

/* start stop register shared by multiple timer channels */
- raw_spin_lock_irqsave(&sh_cmt_lock, flags);
+ raw_spin_lock_irqsave(&ch->cmt->lock, flags);
value = sh_cmt_read_cmstr(ch);

if (start)
@@ -315,7 +315,7 @@ static void sh_cmt_start_stop_ch(struct sh_cmt_channel *ch, int start)
value &= ~(1 << ch->timer_bit);

sh_cmt_write_cmstr(ch, value);
- raw_spin_unlock_irqrestore(&sh_cmt_lock, flags);
+ raw_spin_unlock_irqrestore(&ch->cmt->lock, flags);
}

static int sh_cmt_enable(struct sh_cmt_channel *ch, unsigned long *rate)
@@ -934,6 +934,7 @@ static int sh_cmt_setup(struct sh_cmt_device *cmt, struct platform_device *pdev)

memset(cmt, 0, sizeof(*cmt));
cmt->pdev = pdev;
+ raw_spin_lock_init(&cmt->lock);

if (!cfg) {
dev_err(&cmt->pdev->dev, "missing platform data\n");
--
1.7.9.5


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