Hi,
Huang Shijie wrote:
> hi Marton, thanks a lot.
>
>> From: Márton Németh<nm127@xxxxxxxxxxx>
>>
>> When power management is not configured (CONFIG_PM) then some code is no longer
>> necessary.
>>
>> This patch will remove the following compiler warnings:
>> * pd-dvb.c: In function 'poseidon_fe_release':
>> * pd-dvb.c:101: warning: unused variable 'pd'
>> * pd-video.c:14: warning: 'pm_video_suspend' declared 'static' but never defined
>> * pd-video.c:15: warning: 'pm_video_resume' declared 'static' but never defined
>>
>> Signed-off-by: Márton Németh<nm127@xxxxxxxxxxx>
>> ---
>> diff -r 37581bb7e6f1 linux/drivers/media/video/tlg2300/pd-dvb.c
>> --- a/linux/drivers/media/video/tlg2300/pd-dvb.c Wed Feb 24 22:48:50 2010 -0300
>> +++ b/linux/drivers/media/video/tlg2300/pd-dvb.c Sun Feb 28 15:13:05 2010 +0100
>> @@ -96,15 +96,17 @@
>> return ret;
>> }
>>
>> +#ifdef CONFIG_PM
>> static void poseidon_fe_release(struct dvb_frontend *fe)
>> {
>> struct poseidon *pd = fe->demodulator_priv;
>>
>> -#ifdef CONFIG_PM
>> pd->pm_suspend = NULL;
>> pd->pm_resume = NULL;
>> +}
>> +#else
>> +#define poseidon_fe_release NULL
>> #endif
>> -}
>>
>>
> I think the change here is a little more complicated.I prefer to change
> it like this :
>
> static void poseidon_fe_release(struct dvb_frontend *fe)
> {
> #ifdef CONFIG_PM
> struct poseidon *pd = fe->demodulator_priv;
> pd->pm_suspend = NULL;
> pd->pm_resume = NULL;
> #endif
> }
>
> Could you change the patch, and resend it to me ?
> thanks.
I'm afraid in this case we'll get a warning saying that the parameter fe is unused.
Here is an example:
$ gcc -Wall -O2 -Wextra test.c
test.c: In function ‘foo’:
test.c:2: warning: unused parameter ‘x’
$ cat test.c
static void foo(int x)
{
}
int main()
{
foo(0);
return 0;
}
The second reason I modified the code like this is that the the .release
opreation is used with the following sequence:
if (dvb->frontend->ops.release)
dvb->frontend->ops.release(dvb->frontend);
If power management is not configured then the symbol poseidon_fe_release will be
NULL and the condition dvb->frontend->ops.release will be false. So the otherwise
empty function will not be called at all.
Regards,
Márton Németh
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