Re: [PATCH] drm/hisilicon: Remove redundant null check

[tiantao (H)]

在 2020/11/2 16:32, Thomas Zimmermann 写道:
> Hi
>
> Am 30.10.20 um 10:27 schrieb Tian Tao:
> > drm_irq_uninstall can handle the case where dev->irq_enable is false,
> > so Remove redundant null check.
> >
> > Signed-off-by: Tian Tao <tiantao6@xxxxxxxxxxxxx>
> > ---
> >   drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c | 6 +++---
> >   1 file changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c
> > index 0c1b40d..b71589b1 100644
> > --- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c
> > +++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c
> > @@ -246,13 +246,13 @@ static int hibmc_unload(struct drm_device *dev)
> >   
> >   	drm_atomic_helper_shutdown(dev);
> >   
> > -	if (dev->irq_enabled)
> > -		drm_irq_uninstall(dev);
> > -
> > +	drm_irq_uninstall(dev);
>
> Removing this check would at least result in an error, [1] so rather
> leave it in for now.
Now there seems to be no driver to check the return value of 
drm_irq_uninstall
> Instead, we could discuss if drm_irq_install() should become a managed
> interface.

Codes like the following
diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
index 09d6e9e..572357c 100644
--- a/drivers/gpu/drm/drm_irq.c
+++ b/drivers/gpu/drm/drm_irq.c
@@ -172,6 +172,9 @@ int drm_irq_uninstall(struct drm_device *dev)
        bool irq_enabled;
        int i;

+       if(!dev->irq_enabled || !dev)
+               return 0;

> Best regards
> Thomas
>
> [1]
> https://elixir.bootlin.com/linux/latest/source/drivers/gpu/drm/drm_irq.c#L201
>
> >   	pci_disable_msi(dev->pdev);
> > +
> >   	hibmc_kms_fini(priv);
> >   	hibmc_mm_fini(priv);
> >   	dev->dev_private = NULL;
> > +
> >   	return 0;
> >   }
> >