Subject: [PATCH] drivers/rtc/rtc-twl.c: fix threaded IRQ to use IRQF_ONESHOT

From: [email-masked] (Lars-Peter Clausen)
Date: Tue, 10 Jul 2012 09:32:21 +0200

On 07/10/2012 12:15 AM, Andrew Morton wrote:
> On Fri,  6 Jul 2012 09:33:54 -0700
> Kevin Hilman <[email-masked]> wrote:
> 
>> Requesting a threaded interrupt without a primary handler and without
>> IRQF_ONESHOT is dangerous, and after commit 1c6c6952 (genirq: Reject
>> bogus threaded irq requests), these requests are rejected.  This
>> causes ->probe() to fail, and the RTC driver not to be availble.
>>
>> To fix, add IRQF_ONESHOT to the IRQ flags.
>>
>> Tested on OMAP3730/OveroSTORM and OMAP4430/Panda board using rtcwake
>> to wake from system suspend multiple times.
>>
>> Signed-off-by: Kevin Hilman <[email-masked]>
>> ---
>> Resending to broader audience and including Andrew.  Since, I understand
>> that drivers/rtc is somewhat orphaned, Andrew, can you queue this fix for
>> v3.5.  Thanks.
>>
>>  drivers/rtc/rtc-twl.c |    2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/rtc/rtc-twl.c b/drivers/rtc/rtc-twl.c
>> index 258abea..c5d06fe 100644
>> --- a/drivers/rtc/rtc-twl.c
>> +++ b/drivers/rtc/rtc-twl.c
>> @@ -510,7 +510,7 @@ static int __devinit twl_rtc_probe(struct platform_device *pdev)
>>  	}
>>  
>>  	ret = request_threaded_irq(irq, NULL, twl_rtc_interrupt,
>> -				   IRQF_TRIGGER_RISING,
>> +				   IRQF_TRIGGER_RISING | IRQF_ONESHOT,
>>  				   dev_name(&rtc->dev), rtc);
>>  	if (ret < 0) {
>>  		dev_err(&pdev->dev, "IRQ is not free.\n");
> 
> OK, this is the second such patch I've seen and it's time to wonder if
> we should get grumpy at tglx.  afacit 1c6c6952 broke the following
> drivers:

If you want to be grumpy, be grumpy at Linus. Thomas actually posted a patch
which just emits a warning, instead of failing to request the IRQ, but Linus
didn't want to take it. The whole thread is here
https://lkml.org/lkml/2012/6/12/151

> 
> 
> sound/soc/codecs/wm8994.c
> sound/soc/codecs/max98095.c
> sound/soc/codecs/twl6040.c
> drivers/usb/otg/ab8500-usb.c
> drivers/usb/otg/twl4030-usb.c
> drivers/gpio/gpio-sx150x.c
> drivers/gpio/gpio-ab8500.c
> drivers/mfd/ab8500-gpadc.c
> drivers/mfd/ti-ssp.c
> drivers/mfd/twl4030-madc.c
> drivers/mfd/htc-i2cpld.c
> drivers/mfd/wm831x-auxadc.c
> drivers/mfd/twl6040-core.c
> drivers/mfd/wm8350-core.c
> drivers/extcon/extcon-max8997.c
> drivers/mmc/host/of_mmc_spi.c
> drivers/mmc/core/cd-gpio.c
> drivers/net/can/mcp251x.c
> drivers/nfc/pn544_hci.c
> drivers/nfc/pn544.c
> drivers/power/ab8500_btemp.c
> drivers/power/twl4030_charger.c
> drivers/power/lp8727_charger.c
> drivers/power/smb347-charger.c
> drivers/power/max17042_battery.c
> drivers/power/wm831x_power.c
> drivers/power/ab8500_fg.c
> drivers/power/max8903_charger.c
> drivers/power/ab8500_charger.c
> drivers/regulator/wm831x-isink.c
> drivers/regulator/wm831x-ldo.c
> drivers/regulator/wm831x-dcdc.c
> drivers/staging/ste_rmi4/synaptics_i2c_rmi4.c
> drivers/staging/iio/adc/adt7310.c
> drivers/staging/iio/adc/adt7410.c
> drivers/staging/iio/adc/ad7816.c
> drivers/staging/iio/cdc/ad7150.c
> drivers/staging/iio/accel/sca3000_core.c
> drivers/staging/cptm1217/clearpad_tm1217.c
> drivers/input/keyboard/tc3589x-keypad.c
> drivers/input/keyboard/twl4030_keypad.c
> drivers/input/misc/twl4030-pwrbutton.c
> drivers/input/misc/twl6040-vibra.c
> drivers/input/misc/wm831x-on.c
> drivers/media/radio/si470x/radio-si470x-i2c.c
> drivers/base/regmap/regmap-irq.c
> drivers/rtc/rtc-wm831x.c
> drivers/rtc/rtc-twl.c
> drivers/rtc/rtc-ab8500.c
> drivers/rtc/rtc-max8998.c
> drivers/rtc/rtc-isl1208.c
> drivers/platform/x86/intel_mid_powerbtn.c
> include/linux/mfd/wm8994/core.h
> include/linux/mfd/wm8350/core.h
> 
> what am I missing here?
> 

Most of these drivers are not broken (anymore), the majority drivers which
were broken by Thomas's patch have already been fixed. As for your list:
I've already sent out a fix for all of the staging/iio/ drivers a couple of
days ago. And drivers which use nested interrupts are not affected by this
problem. In your list these are basically all drivers with wm*, twl* and
ab8500 in their names. But still leaves a handful of broken driver which
should be fixed.

- Lars