[PATCH 1/3] staging: comedi: amplc_dio200_common: prevent extra free_irq()
Ian Abbott
abbotti at mev.co.uk
Mon Jul 28 09:27:17 UTC 2014
On 2014-07-27 19:45, Greg Kroah-Hartman wrote:
> On Fri, Jul 25, 2014 at 06:23:10PM +0000, Hartley Sweeten wrote:
>> On Friday, July 25, 2014 10:07 AM, Ian Abbott wrote:
>>> `dio200_detach()` in "amplc_dio200.c" calls
>>> `amplc_dio200_common_detach()` in "amplc_dio200_common.c", followed by
>>> `comedi_legacy_detach()` in "../drivers.c". Both of those functions
>>> call `free_irq()` if `dev->irq` is non-zero. The second call produces a
>>> warning message because the handler has already been freed. Prevent
>>> that by setting `dev->irq = 0` in `amplc_dio200_common_detach()`.
>>>
>>> Signed-off-by: Ian Abbott <abbotti at mev.co.uk>
>>> ---
>>> drivers/staging/comedi/drivers/amplc_dio200_common.c | 4 +++-
>>> 1 file changed, 3 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/staging/comedi/drivers/amplc_dio200_common.c b/drivers/staging/comedi/drivers/amplc_dio200_common.c
>>> index 78700e8..3592e58 100644
>>> --- a/drivers/staging/comedi/drivers/amplc_dio200_common.c
>>> +++ b/drivers/staging/comedi/drivers/amplc_dio200_common.c
>>> @@ -1202,8 +1202,10 @@ void amplc_dio200_common_detach(struct comedi_device *dev)
>>>
>>> if (!thisboard || !devpriv)
>>> return;
>>> - if (dev->irq)
>>> + if (dev->irq) {
>>> free_irq(dev->irq, dev);
>>> + dev->irq = 0;
>>> + }
>>> }
>>> EXPORT_SYMBOL_GPL(amplc_dio200_common_detach);
>>
>> Ian,
>>
>> I have already gave a Reviewed-by signoff for this series.
>>
>> After looking over the code I think a cleaner solution would be to:
>>
>> 1) Use comedi_legacy_detach() directly for the (*detach) in the
>> legacy ISA driver.
>> 2) Move the code from amplc_dio200_common_detach() into the
>> (*detach) function for the PCI driver.
>> 3) Remove the exported function amplc_dio200_common_detach().
>
> So should I not apply these patches?
>
> confused,
>
> greg k-h
It fixes a bug (harmless, apart from a kernel warning), and does no
harm, so might as well apply them. Hartley's suggestion can be done later.
--
-=( Ian Abbott @ MEV Ltd. E-mail: <abbotti at mev.co.uk> )=-
-=( Tel: +44 (0)161 477 1898 FAX: +44 (0)161 718 3587 )=-
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