Re: [PATCH -next] media: staging: tegra-vde: Mark tegra_vde_runtime_suspend as __maybe_unused

From: Dmitry Osipenko
Date: Mon Aug 03 2020 - 10:11:31 EST


03.08.2020 16:00, Yuehaibing пишет:
> On 2020/8/3 20:51, Dmitry Osipenko wrote:
>> 03.08.2020 14:59, YueHaibing пишет:
>>> If CONFIG_PM is not set, gcc warns:
>>>
>>> drivers/staging/media/tegra-vde/vde.c:916:12:
>>> warning: 'tegra_vde_runtime_suspend' defined but not used [-Wunused-function]
>>>
>>> Make it __maybe_unused to fix this.
>>>
>>> Signed-off-by: YueHaibing <yuehaibing@xxxxxxxxxx>
>>> ---
>>> drivers/staging/media/tegra-vde/vde.c | 2 +-
>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/staging/media/tegra-vde/vde.c b/drivers/staging/media/tegra-vde/vde.c
>>> index a3c24d96d5b9..2d043d518eef 100644
>>> --- a/drivers/staging/media/tegra-vde/vde.c
>>> +++ b/drivers/staging/media/tegra-vde/vde.c
>>> @@ -913,7 +913,7 @@ static irqreturn_t tegra_vde_isr(int irq, void *data)
>>> return IRQ_HANDLED;
>>> }
>>>
>>> -static int tegra_vde_runtime_suspend(struct device *dev)
>>> +static __maybe_unused int tegra_vde_runtime_suspend(struct device *dev)
>>> {
>>> struct tegra_vde *vde = dev_get_drvdata(dev);
>>> int err;
>>>
>>
>> Hello Yue,
>>
>> Shouldn't the tegra_vde_runtime_resume() be marked as well?
>
> No, tegra_vde_runtime_resume() always be called by tegra_vde_shutdown().

Well.. it's unused, but compiler doesn't complain about runtime_resume()
because it sees the potential reference to that function in the code
(even that it's a dead code), while runtime_suspend() reference is
completely removed by preprocessor before compiler sees the code.

Should be nicer to have both suspend and resume functions marked, for
consistency, IMO.