linux-kernel - Re: [PATCH] rtc: loongson: clear TOY_MATCH0_REG in loongson_rtc

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Message-ID: <0a7a0508-4303-4ddf-bcd6-8c00e8fcc255@loongson.cn>
Date: Mon, 2 Dec 2024 09:36:24 +0800
From: Ming Wang <wangming01@...ngson.cn>
To: Huacai Chen <chenhuacai@...nel.org>
Cc: Alexandre Belloni <alexandre.belloni@...tlin.com>,
 Keguang Zhang <keguang.zhang@...il.com>,
 Jiaxun Yang <jiaxun.yang@...goat.com>, WANG Xuerui <git@...0n.name>,
 Binbin Zhou <zhoubinbin@...ngson.cn>, linux-rtc@...r.kernel.org,
 linux-kernel@...r.kernel.org, lixuefeng@...ngson.cn, gaojuxin@...ngson.cn
Subject: Re: [PATCH] rtc: loongson: clear TOY_MATCH0_REG in loongson_rtc_isr

Hi, huacai

On 2024/11/29 17:57, Huacai Chen wrote:
> Hi,
> 
> On Thu, Nov 28, 2024 at 3:02 PM Ming Wang <wangming01@...ngson.cn> wrote:
>>
>> The TOY_MATCH0_REG should be cleared to 0 in the RTC interrupt handler,
>> otherwise the interrupt cannot be cleared, which will cause the
>> loongson_rtc_isr to be triggered multiple times.
> Function names usually use () postfixes, e.g., loongson_rtc_isr() and
> loongson_rtc_handler().
> 
OK, I will fix it in the next version.
>>
>> The previous code cleared TOY_MATCH0_REG in the loongson_rtc_handler,
>> which is an ACPI interrupt. This did not prevent loongson_rtc_isr
>> from being triggered multiple times.
>>
>> This commit moves the clearing of TOY_MATCH0_REG to the loongson_rtc_isr
>> to ensure that the interrupt is properly cleared.
>>
>> Fixes: 1b733a9ebc3d ("rtc: Add rtc driver for the Loongson family chips")
>> Signed-off-by: Ming Wang <wangming01@...ngson.cn>
>> ---
>>   drivers/rtc/rtc-loongson.c | 12 +++++++-----
>>   1 file changed, 7 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/rtc/rtc-loongson.c b/drivers/rtc/rtc-loongson.c
>> index e8ffc1ab90b0..0aa30095978b 100644
>> --- a/drivers/rtc/rtc-loongson.c
>> +++ b/drivers/rtc/rtc-loongson.c
>> @@ -114,6 +114,12 @@ static irqreturn_t loongson_rtc_isr(int irq, 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);
> There is usually a blank line before the return statement.
> 
> Huacai
OK, I will fix it in the next version.

Thanks,
Ming
> 
>>          return IRQ_HANDLED;
>>   }
>>
>> @@ -131,11 +137,7 @@ static u32 loongson_rtc_handler(void *id)
>>          writel(RTC_STS, priv->pm_base + PM1_STS_REG);
>>          spin_unlock(&priv->lock);
>>
>> -       /*
>> -        * The TOY_MATCH0_REG should be cleared 0 here,
>> -        * otherwise the interrupt cannot be cleared.
>> -        */
>> -       return regmap_write(priv->regmap, TOY_MATCH0_REG, 0);
>> +       return ACPI_INTERRUPT_HANDLED;
>>   }
>>
>>   static int loongson_rtc_set_enabled(struct device *dev)
>> --
>> 2.43.0
>>