| Message ID | 1383945677-29674-4-git-send-email-soren.brinkmann@xilinx.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 11/08/2013 10:21 PM, Soren Brinkmann wrote: > It is not allowed to call clk_get_rate() from interrupt context. To > avoid such calls the timer input frequency is stored in the driver's > data struct which makes it accessible to the driver in any context. > > Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com> > --- Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> > drivers/clocksource/cadence_ttc_timer.c | 21 +++++++++++++-------- > 1 file changed, 13 insertions(+), 8 deletions(-) > > diff --git a/drivers/clocksource/cadence_ttc_timer.c b/drivers/clocksource/cadence_ttc_timer.c > index b2bb3a4bc205..a92350b55d32 100644 > --- a/drivers/clocksource/cadence_ttc_timer.c > +++ b/drivers/clocksource/cadence_ttc_timer.c > @@ -67,11 +67,13 @@ > * struct ttc_timer - This definition defines local timer structure > * > * @base_addr: Base address of timer > + * @freq: Timer input clock frequency > * @clk: Associated clock source > * @clk_rate_change_nb Notifier block for clock rate changes > */ > struct ttc_timer { > void __iomem *base_addr; > + unsigned long freq; > struct clk *clk; > struct notifier_block clk_rate_change_nb; > }; > @@ -196,9 +198,8 @@ static void ttc_set_mode(enum clock_event_mode mode, > > switch (mode) { > case CLOCK_EVT_MODE_PERIODIC: > - ttc_set_interval(timer, > - DIV_ROUND_CLOSEST(clk_get_rate(ttce->ttc.clk), > - PRESCALE * HZ)); > + ttc_set_interval(timer, DIV_ROUND_CLOSEST(ttce->ttc.freq, > + PRESCALE * HZ)); > break; > case CLOCK_EVT_MODE_ONESHOT: > case CLOCK_EVT_MODE_UNUSED: > @@ -273,6 +274,8 @@ static void __init ttc_setup_clocksource(struct clk *clk, void __iomem *base) > return; > } > > + ttccs->ttc.freq = clk_get_rate(ttccs->ttc.clk); > + > ttccs->ttc.clk_rate_change_nb.notifier_call = > ttc_rate_change_clocksource_cb; > ttccs->ttc.clk_rate_change_nb.next = NULL; > @@ -298,16 +301,14 @@ static void __init ttc_setup_clocksource(struct clk *clk, void __iomem *base) > __raw_writel(CNT_CNTRL_RESET, > ttccs->ttc.base_addr + TTC_CNT_CNTRL_OFFSET); > > - err = clocksource_register_hz(&ttccs->cs, > - clk_get_rate(ttccs->ttc.clk) / PRESCALE); > + err = clocksource_register_hz(&ttccs->cs, ttccs->ttc.freq / PRESCALE); > if (WARN_ON(err)) { > kfree(ttccs); > return; > } > > ttc_sched_clock_val_reg = base + TTC_COUNT_VAL_OFFSET; > - setup_sched_clock(ttc_sched_clock_read, 16, > - clk_get_rate(ttccs->ttc.clk) / PRESCALE); > + setup_sched_clock(ttc_sched_clock_read, 16, ttccs->ttc.freq / PRESCALE); > } > > static int ttc_rate_change_clockevent_cb(struct notifier_block *nb, > @@ -334,6 +335,9 @@ static int ttc_rate_change_clockevent_cb(struct notifier_block *nb, > ndata->new_rate / PRESCALE); > local_irq_restore(flags); > > + /* update cached frequency */ > + ttc->freq = ndata->new_rate; > + > /* fall through */ > } > case PRE_RATE_CHANGE: > @@ -367,6 +371,7 @@ static void __init ttc_setup_clockevent(struct clk *clk, > if (clk_notifier_register(ttcce->ttc.clk, > &ttcce->ttc.clk_rate_change_nb)) > pr_warn("Unable to register clock notifier.\n"); > + ttcce->ttc.freq = clk_get_rate(ttcce->ttc.clk); > > ttcce->ttc.base_addr = base; > ttcce->ce.name = "ttc_clockevent"; > @@ -396,7 +401,7 @@ static void __init ttc_setup_clockevent(struct clk *clk, > } > > clockevents_config_and_register(&ttcce->ce, > - clk_get_rate(ttcce->ttc.clk) / PRESCALE, 1, 0xfffe); > + ttcce->ttc.freq / PRESCALE, 1, 0xfffe); > } > > /** >
diff --git a/drivers/clocksource/cadence_ttc_timer.c b/drivers/clocksource/cadence_ttc_timer.c index b2bb3a4bc205..a92350b55d32 100644 --- a/drivers/clocksource/cadence_ttc_timer.c +++ b/drivers/clocksource/cadence_ttc_timer.c @@ -67,11 +67,13 @@ * struct ttc_timer - This definition defines local timer structure * * @base_addr: Base address of timer + * @freq: Timer input clock frequency * @clk: Associated clock source * @clk_rate_change_nb Notifier block for clock rate changes */ struct ttc_timer { void __iomem *base_addr; + unsigned long freq; struct clk *clk; struct notifier_block clk_rate_change_nb; }; @@ -196,9 +198,8 @@ static void ttc_set_mode(enum clock_event_mode mode, switch (mode) { case CLOCK_EVT_MODE_PERIODIC: - ttc_set_interval(timer, - DIV_ROUND_CLOSEST(clk_get_rate(ttce->ttc.clk), - PRESCALE * HZ)); + ttc_set_interval(timer, DIV_ROUND_CLOSEST(ttce->ttc.freq, + PRESCALE * HZ)); break; case CLOCK_EVT_MODE_ONESHOT: case CLOCK_EVT_MODE_UNUSED: @@ -273,6 +274,8 @@ static void __init ttc_setup_clocksource(struct clk *clk, void __iomem *base) return; } + ttccs->ttc.freq = clk_get_rate(ttccs->ttc.clk); + ttccs->ttc.clk_rate_change_nb.notifier_call = ttc_rate_change_clocksource_cb; ttccs->ttc.clk_rate_change_nb.next = NULL; @@ -298,16 +301,14 @@ static void __init ttc_setup_clocksource(struct clk *clk, void __iomem *base) __raw_writel(CNT_CNTRL_RESET, ttccs->ttc.base_addr + TTC_CNT_CNTRL_OFFSET); - err = clocksource_register_hz(&ttccs->cs, - clk_get_rate(ttccs->ttc.clk) / PRESCALE); + err = clocksource_register_hz(&ttccs->cs, ttccs->ttc.freq / PRESCALE); if (WARN_ON(err)) { kfree(ttccs); return; } ttc_sched_clock_val_reg = base + TTC_COUNT_VAL_OFFSET; - setup_sched_clock(ttc_sched_clock_read, 16, - clk_get_rate(ttccs->ttc.clk) / PRESCALE); + setup_sched_clock(ttc_sched_clock_read, 16, ttccs->ttc.freq / PRESCALE); } static int ttc_rate_change_clockevent_cb(struct notifier_block *nb, @@ -334,6 +335,9 @@ static int ttc_rate_change_clockevent_cb(struct notifier_block *nb, ndata->new_rate / PRESCALE); local_irq_restore(flags); + /* update cached frequency */ + ttc->freq = ndata->new_rate; + /* fall through */ } case PRE_RATE_CHANGE: @@ -367,6 +371,7 @@ static void __init ttc_setup_clockevent(struct clk *clk, if (clk_notifier_register(ttcce->ttc.clk, &ttcce->ttc.clk_rate_change_nb)) pr_warn("Unable to register clock notifier.\n"); + ttcce->ttc.freq = clk_get_rate(ttcce->ttc.clk); ttcce->ttc.base_addr = base; ttcce->ce.name = "ttc_clockevent"; @@ -396,7 +401,7 @@ static void __init ttc_setup_clockevent(struct clk *clk, } clockevents_config_and_register(&ttcce->ce, - clk_get_rate(ttcce->ttc.clk) / PRESCALE, 1, 0xfffe); + ttcce->ttc.freq / PRESCALE, 1, 0xfffe); } /**
It is not allowed to call clk_get_rate() from interrupt context. To avoid such calls the timer input frequency is stored in the driver's data struct which makes it accessible to the driver in any context. Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com> --- drivers/clocksource/cadence_ttc_timer.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-)