Re: [PATCH] Revert "drivers/rtc/rtc-at91rm9200.c: use a variable for storing IMR"

[Nicolas Ferre <nicolas.ferre@atmel.com>]

On 04/03/2013 12:18 PM, Nicolas Ferre :
> On 04/03/2013 11:54 AM, Johan Hovold :
>> This reverts commit 0ef1594c017521ea89278e80fe3f80dafb17abde.
>>
>> This patch introduced a few races which cannot be easily fixed with a
>> small follow-up patch. Furthermore, the SoC with the broken hardware
>> register, which this patch intended to add support for, can only be used
>> with device trees, which this driver currently does not support.
>>
>> Cc: stable <stable@vger.kernel.org>
>> Signed-off-by: Johan Hovold <jhovold@gmail.com>
> 
> Fair enough, after fighting to find a solution that can makes us move
> forward... your strong arguments convinced me.
> 
> So, Andrew, please can you take this "revert" patch for 3.9-rc ?
> And sorry for the noise.
> 
> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
> 
> (Andrew, I figured out that you are not in copy of the original email:
> do I need to send it back to you or can you pick it up in patchwork?
> https://patchwork.kernel.org/patch/2385921/
> )

Andrew, ping?

Thanks, best regards,

>> ---
>>  drivers/rtc/rtc-at91rm9200.c | 50 +++++++++++++++++---------------------------
>>  drivers/rtc/rtc-at91rm9200.h |  1 +
>>  2 files changed, 20 insertions(+), 31 deletions(-)
>>
>> diff --git a/drivers/rtc/rtc-at91rm9200.c b/drivers/rtc/rtc-at91rm9200.c
>> index 0a9f27e..434ebc3 100644
>> --- a/drivers/rtc/rtc-at91rm9200.c
>> +++ b/drivers/rtc/rtc-at91rm9200.c
>> @@ -44,7 +44,6 @@ static DECLARE_COMPLETION(at91_rtc_updated);
>>  static unsigned int at91_alarm_year = AT91_RTC_EPOCH;
>>  static void __iomem *at91_rtc_regs;
>>  static int irq;
>> -static u32 at91_rtc_imr;
>>  
>>  /*
>>   * Decode time/date into rtc_time structure
>> @@ -109,11 +108,9 @@ static int at91_rtc_settime(struct device *dev, struct rtc_time *tm)
>>  	cr = at91_rtc_read(AT91_RTC_CR);
>>  	at91_rtc_write(AT91_RTC_CR, cr | AT91_RTC_UPDCAL | AT91_RTC_UPDTIM);
>>  
>> -	at91_rtc_imr |= AT91_RTC_ACKUPD;
>>  	at91_rtc_write(AT91_RTC_IER, AT91_RTC_ACKUPD);
>>  	wait_for_completion(&at91_rtc_updated);	/* wait for ACKUPD interrupt */
>>  	at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD);
>> -	at91_rtc_imr &= ~AT91_RTC_ACKUPD;
>>  
>>  	at91_rtc_write(AT91_RTC_TIMR,
>>  			  bin2bcd(tm->tm_sec) << 0
>> @@ -145,7 +142,7 @@ static int at91_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
>>  	tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
>>  	tm->tm_year = at91_alarm_year - 1900;
>>  
>> -	alrm->enabled = (at91_rtc_imr & AT91_RTC_ALARM)
>> +	alrm->enabled = (at91_rtc_read(AT91_RTC_IMR) & AT91_RTC_ALARM)
>>  			? 1 : 0;
>>  
>>  	dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
>> @@ -171,7 +168,6 @@ static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
>>  	tm.tm_sec = alrm->time.tm_sec;
>>  
>>  	at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ALARM);
>> -	at91_rtc_imr &= ~AT91_RTC_ALARM;
>>  	at91_rtc_write(AT91_RTC_TIMALR,
>>  		  bin2bcd(tm.tm_sec) << 0
>>  		| bin2bcd(tm.tm_min) << 8
>> @@ -184,7 +180,6 @@ static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
>>  
>>  	if (alrm->enabled) {
>>  		at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
>> -		at91_rtc_imr |= AT91_RTC_ALARM;
>>  		at91_rtc_write(AT91_RTC_IER, AT91_RTC_ALARM);
>>  	}
>>  
>> @@ -201,12 +196,9 @@ static int at91_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
>>  
>>  	if (enabled) {
>>  		at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
>> -		at91_rtc_imr |= AT91_RTC_ALARM;
>>  		at91_rtc_write(AT91_RTC_IER, AT91_RTC_ALARM);
>> -	} else {
>> +	} else
>>  		at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ALARM);
>> -		at91_rtc_imr &= ~AT91_RTC_ALARM;
>> -	}
>>  
>>  	return 0;
>>  }
>> @@ -215,10 +207,12 @@ static int at91_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
>>   */
>>  static int at91_rtc_proc(struct device *dev, struct seq_file *seq)
>>  {
>> +	unsigned long imr = at91_rtc_read(AT91_RTC_IMR);
>> +
>>  	seq_printf(seq, "update_IRQ\t: %s\n",
>> -			(at91_rtc_imr & AT91_RTC_ACKUPD) ? "yes" : "no");
>> +			(imr & AT91_RTC_ACKUPD) ? "yes" : "no");
>>  	seq_printf(seq, "periodic_IRQ\t: %s\n",
>> -			(at91_rtc_imr & AT91_RTC_SECEV) ? "yes" : "no");
>> +			(imr & AT91_RTC_SECEV) ? "yes" : "no");
>>  
>>  	return 0;
>>  }
>> @@ -233,7 +227,7 @@ static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id)
>>  	unsigned int rtsr;
>>  	unsigned long events = 0;
>>  
>> -	rtsr = at91_rtc_read(AT91_RTC_SR) & at91_rtc_imr;
>> +	rtsr = at91_rtc_read(AT91_RTC_SR) & at91_rtc_read(AT91_RTC_IMR);
>>  	if (rtsr) {		/* this interrupt is shared!  Is it ours? */
>>  		if (rtsr & AT91_RTC_ALARM)
>>  			events |= (RTC_AF | RTC_IRQF);
>> @@ -297,7 +291,6 @@ static int __init at91_rtc_probe(struct platform_device *pdev)
>>  	at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
>>  					AT91_RTC_SECEV | AT91_RTC_TIMEV |
>>  					AT91_RTC_CALEV);
>> -	at91_rtc_imr = 0;
>>  
>>  	ret = request_irq(irq, at91_rtc_interrupt,
>>  				IRQF_SHARED,
>> @@ -336,7 +329,6 @@ static int __exit at91_rtc_remove(struct platform_device *pdev)
>>  	at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
>>  					AT91_RTC_SECEV | AT91_RTC_TIMEV |
>>  					AT91_RTC_CALEV);
>> -	at91_rtc_imr = 0;
>>  	free_irq(irq, pdev);
>>  
>>  	rtc_device_unregister(rtc);
>> @@ -349,35 +341,31 @@ static int __exit at91_rtc_remove(struct platform_device *pdev)
>>  
>>  /* AT91RM9200 RTC Power management control */
>>  
>> -static u32 at91_rtc_bkpimr;
>> -
>> +static u32 at91_rtc_imr;
>>  
>>  static int at91_rtc_suspend(struct device *dev)
>>  {
>>  	/* this IRQ is shared with DBGU and other hardware which isn't
>>  	 * necessarily doing PM like we are...
>>  	 */
>> -	at91_rtc_bkpimr = at91_rtc_imr & (AT91_RTC_ALARM|AT91_RTC_SECEV);
>> -	if (at91_rtc_bkpimr) {
>> -		if (device_may_wakeup(dev)) {
>> +	at91_rtc_imr = at91_rtc_read(AT91_RTC_IMR)
>> +			& (AT91_RTC_ALARM|AT91_RTC_SECEV);
>> +	if (at91_rtc_imr) {
>> +		if (device_may_wakeup(dev))
>>  			enable_irq_wake(irq);
>> -		} else {
>> -			at91_rtc_write(AT91_RTC_IDR, at91_rtc_bkpimr);
>> -			at91_rtc_imr &= ~at91_rtc_bkpimr;
>> -		}
>> -}
>> +		else
>> +			at91_rtc_write(AT91_RTC_IDR, at91_rtc_imr);
>> +	}
>>  	return 0;
>>  }
>>  
>>  static int at91_rtc_resume(struct device *dev)
>>  {
>> -	if (at91_rtc_bkpimr) {
>> -		if (device_may_wakeup(dev)) {
>> +	if (at91_rtc_imr) {
>> +		if (device_may_wakeup(dev))
>>  			disable_irq_wake(irq);
>> -		} else {
>> -			at91_rtc_imr |= at91_rtc_bkpimr;
>> -			at91_rtc_write(AT91_RTC_IER, at91_rtc_bkpimr);
>> -		}
>> +		else
>> +			at91_rtc_write(AT91_RTC_IER, at91_rtc_imr);
>>  	}
>>  	return 0;
>>  }
>> diff --git a/drivers/rtc/rtc-at91rm9200.h b/drivers/rtc/rtc-at91rm9200.h
>> index 5f940b6..da1945e 100644
>> --- a/drivers/rtc/rtc-at91rm9200.h
>> +++ b/drivers/rtc/rtc-at91rm9200.h
>> @@ -64,6 +64,7 @@
>>  #define	AT91_RTC_SCCR		0x1c			/* Status Clear Command Register */
>>  #define	AT91_RTC_IER		0x20			/* Interrupt Enable Register */
>>  #define	AT91_RTC_IDR		0x24			/* Interrupt Disable Register */
>> +#define	AT91_RTC_IMR		0x28			/* Interrupt Mask Register */
>>  
>>  #define	AT91_RTC_VER		0x2c			/* Valid Entry Register */
>>  #define		AT91_RTC_NVTIM		(1 <<  0)		/* Non valid Time */
>>
> 
> 


-- 
Nicolas Ferre