[PATCH 2/4] alarmtimer: Make alarmtimer platform device child of RTC device
From: Stephen Boyd
Date: Thu Jan 09 2020 - 10:59:15 EST
The alarmtimer_suspend() function will fail if an RTC device is on a bus
such as SPI or i2c and that RTC device registers and probes after
alarmtimer_init() registers and probes the 'alarmtimer' platform device.
This is because system wide suspend suspends devices in the reverse
order of their probe. When alarmtimer_suspend() attempts to program the
RTC for a wakeup it will try to program an RTC device on a bus that has
already been suspended.
Let's move the alarmtimer device registration to be when the RTC we use
for wakeup is registered. Register the 'alarmtimer' platform device as a
child of the RTC device too, so that we can be guaranteed that the RTC
device won't be suspended when alarmtimer_suspend() is called.
Reported-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
Signed-off-by: Stephen Boyd <swboyd@xxxxxxxxxxxx>
---
kernel/time/alarmtimer.c | 15 +++++----------
1 file changed, 5 insertions(+), 10 deletions(-)
diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
index 4b11f0309eee..ccb6aea4f1d4 100644
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -88,6 +88,7 @@ static int alarmtimer_rtc_add_device(struct device *dev,
unsigned long flags;
struct rtc_device *rtc = to_rtc_device(dev);
struct wakeup_source *__ws;
+ struct platform_device *pdev;
int ret = 0;
if (rtcdev)
@@ -99,6 +100,7 @@ static int alarmtimer_rtc_add_device(struct device *dev,
return -1;
__ws = wakeup_source_register(dev, "alarmtimer");
+ pdev = platform_device_register_data(dev, "alarmtimer", -1, NULL, 0);
spin_lock_irqsave(&rtcdev_lock, flags);
if (!rtcdev) {
@@ -112,10 +114,12 @@ static int alarmtimer_rtc_add_device(struct device *dev,
get_device(dev);
ws = __ws;
__ws = NULL;
+ pdev = NULL;
}
unlock:
spin_unlock_irqrestore(&rtcdev_lock, flags);
+ platform_device_unregister(pdev);
wakeup_source_unregister(__ws);
return ret;
@@ -876,8 +880,7 @@ static struct platform_driver alarmtimer_driver = {
*/
static int __init alarmtimer_init(void)
{
- struct platform_device *pdev;
- int error = 0;
+ int error;
int i;
alarmtimer_rtc_timer_init();
@@ -900,15 +903,7 @@ static int __init alarmtimer_init(void)
if (error)
goto out_if;
- pdev = platform_device_register_simple("alarmtimer", -1, NULL, 0);
- if (IS_ERR(pdev)) {
- error = PTR_ERR(pdev);
- goto out_drv;
- }
return 0;
-
-out_drv:
- platform_driver_unregister(&alarmtimer_driver);
out_if:
alarmtimer_rtc_interface_remove();
return error;
--
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