From 65ada547d68dc075aa06df92fe325bff07cbc606 Mon Sep 17 00:00:00 2001 From: Takashi YOSHII Date: Fri, 17 Dec 2010 07:25:09 +0000 Subject: [PATCH] clocksource: sh_cmt: Remove nested spinlock fix There are control flow that sh_cmt_set_next() does double spin-lock. The callers sh_cmt_{start,stop}() already have lock. But another callers sh_cmt_clock_event_{start,next}() does not. Now sh_cmt_set_next() does not lock by itself. All the callers should hold spin-lock before calling it. [damm@opensource.se: use __sh_cmt_set_next() to simplify code] [damm@opensource.se: added stable, suitable for v2.6.35 + v2.6.36] Cc: stable@kernel.org Signed-off-by: Takashi YOSHII Signed-off-by: Magnus Damm Signed-off-by: Paul Mundt --- drivers/clocksource/sh_cmt.c | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) diff --git a/drivers/clocksource/sh_cmt.c b/drivers/clocksource/sh_cmt.c index d68d3aa1814..f975d24890f 100644 --- a/drivers/clocksource/sh_cmt.c +++ b/drivers/clocksource/sh_cmt.c @@ -283,16 +283,21 @@ static void sh_cmt_clock_event_program_verify(struct sh_cmt_priv *p, } while (delay); } +static void __sh_cmt_set_next(struct sh_cmt_priv *p, unsigned long delta) +{ + if (delta > p->max_match_value) + dev_warn(&p->pdev->dev, "delta out of range\n"); + + p->next_match_value = delta; + sh_cmt_clock_event_program_verify(p, 0); +} + static void sh_cmt_set_next(struct sh_cmt_priv *p, unsigned long delta) { unsigned long flags; - if (delta > p->max_match_value) - dev_warn(&p->pdev->dev, "delta out of range\n"); - spin_lock_irqsave(&p->lock, flags); - p->next_match_value = delta; - sh_cmt_clock_event_program_verify(p, 0); + __sh_cmt_set_next(p, delta); spin_unlock_irqrestore(&p->lock, flags); } @@ -359,7 +364,7 @@ static int sh_cmt_start(struct sh_cmt_priv *p, unsigned long flag) /* setup timeout if no clockevent */ if ((flag == FLAG_CLOCKSOURCE) && (!(p->flags & FLAG_CLOCKEVENT))) - sh_cmt_set_next(p, p->max_match_value); + __sh_cmt_set_next(p, p->max_match_value); out: spin_unlock_irqrestore(&p->lock, flags); @@ -381,7 +386,7 @@ static void sh_cmt_stop(struct sh_cmt_priv *p, unsigned long flag) /* adjust the timeout to maximum if only clocksource left */ if ((flag == FLAG_CLOCKEVENT) && (p->flags & FLAG_CLOCKSOURCE)) - sh_cmt_set_next(p, p->max_match_value); + __sh_cmt_set_next(p, p->max_match_value); spin_unlock_irqrestore(&p->lock, flags); }