diff mbox series

rtc: loongson: Add missing alarm notifications for ACPI RTC events

Message ID 20250429062736.982039-1-liudalin@kylinsec.com.cn
State Superseded
Headers show
Series rtc: loongson: Add missing alarm notifications for ACPI RTC events | expand

Commit Message

Liu Dalin April 29, 2025, 6:27 a.m. UTC
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 | 2 ++
 1 file changed, 2 insertions(+)

Comments

Binbin Zhou May 8, 2025, 3:12 a.m. UTC | #1
Hi Dalin:

Thanks for your patch.

On 2025/4/29 14:27, 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>
> ---
>   drivers/rtc/rtc-loongson.c | 2 ++
>   1 file changed, 2 insertions(+)
>
> diff --git a/drivers/rtc/rtc-loongson.c b/drivers/rtc/rtc-loongson.c
> index 97e5625c064c..0c573f198f63 100644
> --- a/drivers/rtc/rtc-loongson.c
> +++ b/drivers/rtc/rtc-loongson.c
> @@ -129,6 +129,8 @@ 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);
> +
While testing the patch, I noticed that interrupts are triggered 
multiple times (/proc/interrupt), not sure if you have the same issue.

I think we need a similar operation to loongson_rtc_isr() to clear the 
interrupt:
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
liudalin@kylinos.com.cn May 8, 2025, 6:43 a.m. UTC | #2
Hi Binbin:
   The described issue does not happened  with or without the patch by test, as the interrupt is managed by acpi. 

   The device info and test result are as follows.

1. Device info
[系统未激活][root@mail test]# dmidecode -q
BIOS Information
        Vendor: ZD-TECH
        Version: V09
        Release Date: 06/15/2022
        ROM Size: 8 MB
        Characteristics:
                PCI is supported
                BIOS is upgradeable
                BIOS shadowing is allowed
                Boot from CD is supported
                Selectable boot is supported
                BIOS ROM is socketed
                Serial services are supported (int 14h)
                USB legacy is supported
                Function key-initiated network boot is supported
                UEFI is supported
        BIOS Revision: 4.0
        Firmware Revision: 0.4

System Information
        Manufacturer: GEIT
        Product Name: UT6000-LB5
        Version: 1.0
        Serial Number: TBD by OEM
        UUID: 00112233-4455-6677-8899-aabbccddeeff
        Wake-up Type: Power Switch
        SKU Number: Loongson_SKU
        Family: Type1Family

Base Board Information
        Manufacturer: GEIT
        Product Name: GG-3A5000-02
        Version: 1.0
        Serial Number: Chassis Board Serial#To Be Filled By O.E.M
        Asset Tag: Type2 - Board Asset Tag
        Features:
                Board is a hosting board
                Board is replaceable
        Location In Chassis: Type2 - Board Chassis Location
        Type: Motherboard
...

2. The system exhibits a timeout error when waiting for alarm signal response without the patch.
[系统未激活][root@mail test]# cat /proc/interrupts |grep acpi
21:          3          0          0          0   PCH PIC   1  acpi
[系统未激活][root@mail test]#
[系统未激活][root@mail test]# ./rtc01
RTC READ TEST:
RTC READ TEST Passed
Current RTC date/time is 8-5-2025, 05:50:05.
RTC ALARM TEST :Alarm time set to 05:50:10.
Waiting 5 seconds for the alarm...
Timed out waiting for the alarm
RTC UPDATE INTERRUPTS TEST :
RTC_UIE_ON not supported
RTC Tests Done!
[系统未激活][root@mail test]#
[系统未激活][root@mail test]# cat /proc/interrupts |grep acpi
21:          4          0          0          0   PCH PIC   1  acpi
[系统未激活][root@mail test]#

3. There is no error with the patch applied and the interrupts are triggered ok
[系统未激活][root@mail test]# cat /proc/interrupts |grep acpi
21:          0          0          0          0   PCH PIC   1  acpi
[系统未激活][root@mail test]#
[系统未激活][root@mail test]# ./rtc01
RTC READ TEST:
RTC READ TEST Passed
Current RTC date/time is 8-5-2025, 06:09:03.
RTC ALARM TEST :Alarm time set to 06:09:08.
Waiting 5 seconds for the alarm...
Alarm rang.
RTC ALARM TEST Passed
RTC UPDATE INTERRUPTS TEST :
RTC_UIE_ON not supported
RTC Tests Done!
[系统未激活][root@mail test]#
[系统未激活][root@mail test]# cat /proc/interrupts |grep acpi
21:          1          0          0          0   PCH PIC   1  acpi
[系统未激活][root@mail test]#





From: Binbin Zhou



Date: 2025-05-08 11:12



To: Liu Dalin; alexandre.belloni; wangming01



CC: chenhuacai; gaojuxin; git; jiaxun.yang; keguang.zhang; lixuefeng; linux-rtc; linux-kernel; zhoubb.aaron



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



Hi Dalin:



 



Thanks for your patch.



 



On 2025/4/29 14:27, 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>



> ---



>   drivers/rtc/rtc-loongson.c | 2 ++



>   1 file changed, 2 insertions(+)



>



> diff --git a/drivers/rtc/rtc-loongson.c b/drivers/rtc/rtc-loongson.c



> index 97e5625c064c..0c573f198f63 100644



> --- a/drivers/rtc/rtc-loongson.c



> +++ b/drivers/rtc/rtc-loongson.c



> @@ -129,6 +129,8 @@ 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);



> +



While testing the patch, I noticed that interrupts are triggered



multiple times (/proc/interrupt), not sure if you have the same issue.



 



I think we need a similar operation to loongson_rtc_isr() to clear the



interrupt:



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
Binbin Zhou May 8, 2025, 6:48 a.m. UTC | #3
Hi:

On Thu, May 8, 2025 at 2:20 PM liudalin@kylinos.com.cn
<liudalin@kylinos.com.cn> wrote:
>
> Hi Binbin:
>    The described issue does not happened  with or without the patch by test, as the interrupt is managed by acpi.

I see it.
>
> The device info and test result are as follows.
>
> 1. Device info
> [系统未激活][root@mail test]# dmidecode
> # dmidecode 3.5
> Getting SMBIOS data from sysfs.
> SMBIOS 3.2.0 present.
> Table at 0x90000000FD620000.
>
> Handle 0x0000, DMI type 0, 24 bytes
> BIOS Information
>         Vendor: ZD-TECH
>         Version: V09
>         Release Date: 06/15/2022
>         ROM Size: 8 MB
>         Characteristics:
>                 PCI is supported
>                 BIOS is upgradeable
>                 BIOS shadowing is allowed
>                 Boot from CD is supported
>                 Selectable boot is supported
>                 BIOS ROM is socketed
>                 Serial services are supported (int 14h)
>                 USB legacy is supported
>                 Function key-initiated network boot is supported
>                 UEFI is supported
>         BIOS Revision: 4.0
>         Firmware Revision: 0.4
>
> Handle 0x0001, DMI type 1, 27 bytes
> System Information
>         Manufacturer: GEIT
>         Product Name: UT6000-LB5
>         Version: 1.0
>         Serial Number: TBD by OEM
>         UUID: 00112233-4455-6677-8899-aabbccddeeff
>         Wake-up Type: Power Switch
>         SKU Number: Loongson_SKU
>         Family: Type1Family
>
> Handle 0x0002, DMI type 2, 15 bytes
> Base Board Information
>         Manufacturer: GEIT
>         Product Name: GG-3A5000-02

My machine is also Loongosn-3A5000 + 7A2000, I think this should not affect.

>         Version: 1.0
>         Serial Number: Chassis Board Serial#To Be Filled By O.E.M
>         Asset Tag: Type2 - Board Asset Tag
>         Features:
>                 Board is a hosting board
>                 Board is replaceable
>         Location In Chassis: Type2 - Board Chassis Location
>         Chassis Handle: 0xFFFF
>         Type: Motherboard
>         Contained Object Handles: 0
>
> 2. The system exhibits a timeout error when waiting for alarm signal response without the patch.
> [系统未激活][root@mail test]# cat /proc/interrupts |grep acpi
>  21:          3          0          0          0   PCH PIC   1  acpi
> [系统未激活][root@mail test]#
> [系统未激活][root@mail test]# ./rtc01
> RTC READ TEST:
> RTC READ TEST Passed
> Current RTC date/time is 8-5-2025, 05:50:05.
> RTC ALARM TEST :Alarm time set to 05:50:10.
> Waiting 5 seconds for the alarm...
> Timed out waiting for the alarm
> RTC UPDATE INTERRUPTS TEST :
> RTC_UIE_ON not supported
> RTC Tests Done!
> [系统未激活][root@mail test]#
> [系统未激活][root@mail test]# cat /proc/interrupts |grep acpi
>  21:          4          0          0          0   PCH PIC   1  acpi
> [系统未激活][root@mail test]#
>
Please try continuous testing to see if you get different results.

Here is my test code, it behaves fine on Loongson-2K1000, you can
compare it with yours.
https://gist.github.com/AaronDot/affafc0b861783aee128a76b34d45f55

Also, your test code can be provided to me for testing.

> 3. There is no error with the patch applied and the interrupts are triggered ok
> [系统未激活][root@mail test]# cat /proc/interrupts |grep acpi
>  21:          0          0          0          0   PCH PIC   1  acpi
> [系统未激活][root@mail test]#
> [系统未激活][root@mail test]# ./rtc01
> RTC READ TEST:
> RTC READ TEST Passed
> Current RTC date/time is 8-5-2025, 06:09:03.
> RTC ALARM TEST :Alarm time set to 06:09:08.
> Waiting 5 seconds for the alarm...
> Alarm rang.
> RTC ALARM TEST Passed
> RTC UPDATE INTERRUPTS TEST :
> RTC_UIE_ON not supported
> RTC Tests Done!
> [系统未激活][root@mail test]#
> [系统未激活][root@mail test]# cat /proc/interrupts |grep acpi
>  21:          1          0          0          0   PCH PIC   1  acpi
> [系统未激活][root@mail test]#
>
>
> ________________________________
> liudalin@kylinos.com.cn
>
>
> From: Binbin Zhou
> Date: 2025-05-08 11:12
> To: Liu Dalin; alexandre.belloni; wangming01
> CC: chenhuacai; gaojuxin; git; jiaxun.yang; keguang.zhang; lixuefeng; linux-rtc; linux-kernel; zhoubb.aaron
> Subject: Re: [PATCH] rtc: loongson: Add missing alarm notifications for ACPI RTC events
> Hi Dalin:
>
> Thanks for your patch.
>
> On 2025/4/29 14:27, 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>
> > ---
> >   drivers/rtc/rtc-loongson.c | 2 ++
> >   1 file changed, 2 insertions(+)
> >
> > diff --git a/drivers/rtc/rtc-loongson.c b/drivers/rtc/rtc-loongson.c
> > index 97e5625c064c..0c573f198f63 100644
> > --- a/drivers/rtc/rtc-loongson.c
> > +++ b/drivers/rtc/rtc-loongson.c
> > @@ -129,6 +129,8 @@ 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);
> > +
> While testing the patch, I noticed that interrupts are triggered
> multiple times (/proc/interrupt), not sure if you have the same issue.
>
> I think we need a similar operation to loongson_rtc_isr() to clear the
> interrupt:
> 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
>
>
>
diff mbox series

Patch

diff --git a/drivers/rtc/rtc-loongson.c b/drivers/rtc/rtc-loongson.c
index 97e5625c064c..0c573f198f63 100644
--- a/drivers/rtc/rtc-loongson.c
+++ b/drivers/rtc/rtc-loongson.c
@@ -129,6 +129,8 @@  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);
+
 	spin_lock(&priv->lock);
 	/* Disable RTC alarm wakeup and interrupt */
 	writel(readl(priv->pm_base + PM1_EN_REG) & ~RTC_EN,