Subject: [PATCH] ARM AT91: clocksource tcb_clksrc.c: make tc_mode interrupt safe

From: [email-masked] (Nicolas Ferre)
Date: Thu, 22 May 2014 18:33:40 +0200

On 22/05/2014 15:32, Alexandre Belloni :
> On 08/05/2014 at 12:06:25 +0200, David Jander wrote :
>> tc_mode() can be called from interrupt context and thus must not call
>> clk_*prepare*() functions.
>>
>> Signed-off-by: David Jander <[email-masked]>
> 
> Acked-by: Alexandre Belloni <[email-masked]>

Ok, indeed. We keep the clocks prepared for the system lifetime.

Acked-by: Nicolas Ferre <[email-masked]>

Daniel, can you please take this fix (do you want me to re-send it)?

Bye,

>> ---
>>  drivers/clocksource/tcb_clksrc.c | 8 ++++----
>>  1 file changed, 4 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c
>> index 00fdd11..a8d7ea1 100644
>> --- a/drivers/clocksource/tcb_clksrc.c
>> +++ b/drivers/clocksource/tcb_clksrc.c
>> @@ -100,7 +100,7 @@ static void tc_mode(enum clock_event_mode m, struct clock_event_device *d)
>>  			|| tcd->clkevt.mode == CLOCK_EVT_MODE_ONESHOT) {
>>  		__raw_writel(0xff, regs + ATMEL_TC_REG(2, IDR));
>>  		__raw_writel(ATMEL_TC_CLKDIS, regs + ATMEL_TC_REG(2, CCR));
>> -		clk_disable_unprepare(tcd->clk);
>> +		clk_disable(tcd->clk);
>>  	}
>>  
>>  	switch (m) {
>> @@ -109,7 +109,7 @@ static void tc_mode(enum clock_event_mode m, struct clock_event_device *d)
>>  	 * of oneshot, we get lower overhead and improved accuracy.
>>  	 */
>>  	case CLOCK_EVT_MODE_PERIODIC:
>> -		clk_prepare_enable(tcd->clk);
>> +		clk_enable(tcd->clk);
>>  
>>  		/* slow clock, count up to RC, then irq and restart */
>>  		__raw_writel(timer_clock
>> @@ -126,7 +126,7 @@ static void tc_mode(enum clock_event_mode m, struct clock_event_device *d)
>>  		break;
>>  
>>  	case CLOCK_EVT_MODE_ONESHOT:
>> -		clk_prepare_enable(tcd->clk);
>> +		clk_enable(tcd->clk);
>>  
>>  		/* slow clock, count up to RC, then irq and stop */
>>  		__raw_writel(timer_clock | ATMEL_TC_CPCSTOP
>> @@ -194,7 +194,7 @@ static int __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
>>  	ret = clk_prepare_enable(t2_clk);
>>  	if (ret)
>>  		return ret;
>> -	clk_disable_unprepare(t2_clk);
>> +	clk_disable(t2_clk);
>>  
>>  	clkevt.regs = tc->regs;
>>  	clkevt.clk = t2_clk;
>> -- 
>> 1.9.1
>>
>>
>> _______________________________________________
>> linux-arm-kernel mailing list
>> linux-arm-kernel at lists.infradead.org
>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
> 

-- 
Nicolas Ferre