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[PATCH V1] rtc: loongson: Add missing alarm notifications for ACPI RTC events

Liu Dalin posted 1 patch 9 months ago
There is a newer version of this series
drivers/rtc/rtc-loongson.c | 8 ++++++++
1 file changed, 8 insertions(+)
[PATCH V1] rtc: loongson: Add missing alarm notifications for ACPI RTC events
Posted by Liu Dalin 9 months ago 
When an application sets and enables an alarm on Loongson RTC devices,
the alarm notification fails to propagate to userspace because the
ACPI event handler omits calling rtc_update_irq().

As a result, processes waiting via select() or poll() on RTC device
files fail to receive alarm notifications.

Fixes: 1b733a9ebc3d ("rtc: Add rtc driver for the Loongson family chips")
Signed-off-by: Liu Dalin <liudalin@kylinsec.com.cn>
---
 drivers/rtc/rtc-loongson.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/rtc/rtc-loongson.c b/drivers/rtc/rtc-loongson.c
index 97e5625c064c..2ca7ffd5d7a9 100644
--- a/drivers/rtc/rtc-loongson.c
+++ b/drivers/rtc/rtc-loongson.c
@@ -129,6 +129,14 @@ static u32 loongson_rtc_handler(void *id)
 {
 	struct loongson_rtc_priv *priv = (struct loongson_rtc_priv *)id;
 
+	rtc_update_irq(priv->rtcdev, 1, RTC_AF | RTC_IRQF);
+
+	/*
+	 * The TOY_MATCH0_REG should be cleared 0 here,
+	 * otherwise the interrupt cannot be cleared.
+	 */
+	regmap_write(priv->regmap, TOY_MATCH0_REG, 0);
+
 	spin_lock(&priv->lock);
 	/* Disable RTC alarm wakeup and interrupt */
 	writel(readl(priv->pm_base + PM1_EN_REG) & ~RTC_EN,
-- 
2.33.0
Re: [PATCH V1] rtc: loongson: Add missing alarm notifications for ACPI RTC events
Posted by Binbin Zhou 9 months ago 
Hi:

On 2025/5/9 09:40, Liu Dalin wrote:
> When an application sets and enables an alarm on Loongson RTC devices,
> the alarm notification fails to propagate to userspace because the
> ACPI event handler omits calling rtc_update_irq().
>
> As a result, processes waiting via select() or poll() on RTC device
> files fail to receive alarm notifications.
>
> Fixes: 1b733a9ebc3d ("rtc: Add rtc driver for the Loongson family chips")
> Signed-off-by: Liu Dalin <liudalin@kylinsec.com.cn>
Technically I don't think this is a compliant patch, firstly this patch 
should be V2 and also you should add "Changlog" for describing the 
differences from the previous patch.
Anyway, it's good to me.

Reviewed-by: Binbin Zhou <zhoubinbin@loongson.cn>

> ---
>   drivers/rtc/rtc-loongson.c | 8 ++++++++
>   1 file changed, 8 insertions(+)
>
> diff --git a/drivers/rtc/rtc-loongson.c b/drivers/rtc/rtc-loongson.c
> index 97e5625c064c..2ca7ffd5d7a9 100644
> --- a/drivers/rtc/rtc-loongson.c
> +++ b/drivers/rtc/rtc-loongson.c
> @@ -129,6 +129,14 @@ static u32 loongson_rtc_handler(void *id)
>   {
>   	struct loongson_rtc_priv *priv = (struct loongson_rtc_priv *)id;
>   
> +	rtc_update_irq(priv->rtcdev, 1, RTC_AF | RTC_IRQF);
> +
> +	/*
> +	 * The TOY_MATCH0_REG should be cleared 0 here,
> +	 * otherwise the interrupt cannot be cleared.
> +	 */
> +	regmap_write(priv->regmap, TOY_MATCH0_REG, 0);
> +
>   	spin_lock(&priv->lock);
>   	/* Disable RTC alarm wakeup and interrupt */
>   	writel(readl(priv->pm_base + PM1_EN_REG) & ~RTC_EN,
Thanks.
Binbin
Re: [PATCH V1] rtc: loongson: Add missing alarm notifications for ACPI RTC events
Posted by Liu Dalin 9 months ago 

在 2025/5/9 15:12, Binbin Zhou 写道:
> Hi:
> 
> On 2025/5/9 09:40, Liu Dalin wrote:
>> When an application sets and enables an alarm on Loongson RTC devices,
>> the alarm notification fails to propagate to userspace because the
>> ACPI event handler omits calling rtc_update_irq().
>>
>> As a result, processes waiting via select() or poll() on RTC device
>> files fail to receive alarm notifications.
>>
>> Fixes: 1b733a9ebc3d ("rtc: Add rtc driver for the Loongson family chips")
>> Signed-off-by: Liu Dalin <liudalin@kylinsec.com.cn>
> Technically I don't think this is a compliant patch, firstly this patch 
> should be V2 and also you should add "Changlog" for describing the 
> differences from the previous patch.
> Anyway, it's good to me.

Ok! There is another problem, if regmap_write(priv->regmap,
TOY_MATCH0_REG, 0) move to the end of loongson_rtc_handler as 
09471d8f5b39("rtc: loongson: clear TOY_MATCH0_REG in 
loongson_rtc_isr()"), the interrupt also can be triggered multiple times.

So the regmap_write(priv->regmap,TOY_MATCH0_REG, 0) is move behind of 
rtc_update_irq by me, then the interrupt was triggered OK.

Is there any problem ?

> 
> Reviewed-by: Binbin Zhou <zhoubinbin@loongson.cn>
> 
>> ---
>>   drivers/rtc/rtc-loongson.c | 8 ++++++++
>>   1 file changed, 8 insertions(+)
>>
>> diff --git a/drivers/rtc/rtc-loongson.c b/drivers/rtc/rtc-loongson.c
>> index 97e5625c064c..2ca7ffd5d7a9 100644
>> --- a/drivers/rtc/rtc-loongson.c
>> +++ b/drivers/rtc/rtc-loongson.c
>> @@ -129,6 +129,14 @@ static u32 loongson_rtc_handler(void *id)
>>   {
>>       struct loongson_rtc_priv *priv = (struct loongson_rtc_priv *)id;
>> +    rtc_update_irq(priv->rtcdev, 1, RTC_AF | RTC_IRQF);
>> +
>> +    /*
>> +     * The TOY_MATCH0_REG should be cleared 0 here,
>> +     * otherwise the interrupt cannot be cleared.
>> +     */
>> +    regmap_write(priv->regmap, TOY_MATCH0_REG, 0);
>> +
>>       spin_lock(&priv->lock);
>>       /* Disable RTC alarm wakeup and interrupt */
>>       writel(readl(priv->pm_base + PM1_EN_REG) & ~RTC_EN,
> Thanks.
> Binbin
> 
> 
>
Re: [PATCH V1] rtc: loongson: Add missing alarm notifications for ACPI RTC events
Posted by Binbin Zhou 9 months ago 
On 2025/5/9 16:06, Liu Dalin wrote:
>
>
> 在 2025/5/9 15:12, Binbin Zhou 写道:
>> Hi:
>>
>> On 2025/5/9 09:40, Liu Dalin wrote:
>>> When an application sets and enables an alarm on Loongson RTC devices,
>>> the alarm notification fails to propagate to userspace because the
>>> ACPI event handler omits calling rtc_update_irq().
>>>
>>> As a result, processes waiting via select() or poll() on RTC device
>>> files fail to receive alarm notifications.
>>>
>>> Fixes: 1b733a9ebc3d ("rtc: Add rtc driver for the Loongson family 
>>> chips")
>>> Signed-off-by: Liu Dalin <liudalin@kylinsec.com.cn>
>> Technically I don't think this is a compliant patch, firstly this 
>> patch should be V2 and also you should add "Changlog" for describing 
>> the differences from the previous patch.
>> Anyway, it's good to me.
>
> Ok! There is another problem, if regmap_write(priv->regmap,
> TOY_MATCH0_REG, 0) move to the end of loongson_rtc_handler as 
> 09471d8f5b39("rtc: loongson: clear TOY_MATCH0_REG in 
> loongson_rtc_isr()"), the interrupt also can be triggered multiple times.
>
> So the regmap_write(priv->regmap,TOY_MATCH0_REG, 0) is move behind of 
> rtc_update_irq by me, then the interrupt was triggered OK.
>
> Is there any problem ?

It is ok. That's where I added it when I suggested it before.

Thanks.
Binbin

>
>>
>> Reviewed-by: Binbin Zhou <zhoubinbin@loongson.cn>
>>
>>> ---
>>>   drivers/rtc/rtc-loongson.c | 8 ++++++++
>>>   1 file changed, 8 insertions(+)
>>>
>>> diff --git a/drivers/rtc/rtc-loongson.c b/drivers/rtc/rtc-loongson.c
>>> index 97e5625c064c..2ca7ffd5d7a9 100644
>>> --- a/drivers/rtc/rtc-loongson.c
>>> +++ b/drivers/rtc/rtc-loongson.c
>>> @@ -129,6 +129,14 @@ static u32 loongson_rtc_handler(void *id)
>>>   {
>>>       struct loongson_rtc_priv *priv = (struct loongson_rtc_priv *)id;
>>> +    rtc_update_irq(priv->rtcdev, 1, RTC_AF | RTC_IRQF);
>>> +
>>> +    /*
>>> +     * The TOY_MATCH0_REG should be cleared 0 here,
>>> +     * otherwise the interrupt cannot be cleared.
>>> +     */
>>> +    regmap_write(priv->regmap, TOY_MATCH0_REG, 0);
>>> +
>>>       spin_lock(&priv->lock);
>>>       /* Disable RTC alarm wakeup and interrupt */
>>>       writel(readl(priv->pm_base + PM1_EN_REG) & ~RTC_EN,
>> Thanks.
>> Binbin
>>
>>
>>

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