On 22/02/2017 04:33, Alexandre Belloni wrote:
On 17/02/2017 at 09:44:58 +0800, Phil Reid wrote:
The wakealarm attribute is currently not exposed in the sysfs interface
as the device has not been set as doing wakealarm when device_register
is called. Changing the order of the calls fixes that problem. Interrupts
are cleared in check_rtc_status prior to requesting the interrupt.


This basically revert b4b77f3c280e38cec178f81d7a4d7e65f4045913 So I'm
not sure this is sufficient to ensure the IRQ will never fire.

(I don't know whether this was a real bug or something reported by a
static analysis tool).

G'day Alexandre,
Without this change the wakealarm sysfs is never created.
This is done in rtc_device_register, but a filter to wakealarm attribute 
effectively on
dev->power.can_wakeup flag. Which is set via the init wakeup call.

But looking at that commit and thinking about it some more I can see the problem
b4b77f3c280e38cec178f81d7a4d7e65f4045913 was try to solve.

Looking at other drivers some of them have similar order but use their own 
mutex.
eg rtc-rc8803 and don't use the ops_lock

Or others set device_init_wakeup and then fail if the irq fails to register.

Currently if the ds3232 has an irq set but fails to register the irq it falls 
back
to being a non wakeup source. To me it makes more sense to just fall if the 
config
has an irq defined.

Then we could set device_init_wakeup based on there being an irq prior to 
device_register
and then request the irq after device register. But fail the probe if the irq 
request fails.

Thoughts?


Signed-off-by: Phil Reid <[email protected]>
---
 drivers/rtc/rtc-ds3232.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/rtc/rtc-ds3232.c b/drivers/rtc/rtc-ds3232.c
index 60de3a0..ce943d0 100644
--- a/drivers/rtc/rtc-ds3232.c
+++ b/drivers/rtc/rtc-ds3232.c
@@ -363,11 +363,6 @@ static int ds3232_probe(struct device *dev, struct regmap 
*regmap, int irq,
        if (ret)
                return ret;

-       ds3232->rtc = devm_rtc_device_register(dev, name, &ds3232_rtc_ops,
-                                               THIS_MODULE);
-       if (IS_ERR(ds3232->rtc))
-               return PTR_ERR(ds3232->rtc);
-
        if (ds3232->irq > 0) {
                ret = devm_request_threaded_irq(dev, ds3232->irq, NULL,
                                                ds3232_irq,
@@ -380,6 +375,11 @@ static int ds3232_probe(struct device *dev, struct regmap 
*regmap, int irq,
                        device_init_wakeup(dev, 1);
        }

+       ds3232->rtc = devm_rtc_device_register(dev, name, &ds3232_rtc_ops,
+               THIS_MODULE);
+       if (IS_ERR(ds3232->rtc))
+               return PTR_ERR(ds3232->rtc);
+
        return 0;
 }

--
1.8.3.1




--
Regards
Phil Reid

ElectroMagnetic Imaging Technology Pty Ltd
Development of Geophysical Instrumentation & Software
www.electromag.com.au

3 The Avenue, Midland WA 6056, AUSTRALIA
Ph: +61 8 9250 8100
Fax: +61 8 9250 7100
Email: [email protected]

--
You received this message because you are subscribed to "rtc-linux".
Membership options at http://groups.google.com/group/rtc-linux .
Please read http://groups.google.com/group/rtc-linux/web/checklist
before submitting a driver.
--- You received this message because you are subscribed to the Google Groups "rtc-linux" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to [email protected].
For more options, visit https://groups.google.com/d/optout.

Reply via email to