| Message ID | 1454025916-5218-1-git-send-email-wuninsu@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, 28 Jan 2016 19:05:16 -0500 Insu Yun <wuninsu@gmail.com> wrote: > Since drm_property_create_range can be failed in memory pressure, > it needs to be handled. > > Signed-off-by: Insu Yun <wuninsu@gmail.com> > --- > drivers/gpu/drm/gma500/framebuffer.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/gpu/drm/gma500/framebuffer.c b/drivers/gpu/drm/gma500/framebuffer.c > index cb95765..31085e4 100644 > --- a/drivers/gpu/drm/gma500/framebuffer.c > +++ b/drivers/gpu/drm/gma500/framebuffer.c > @@ -683,6 +683,8 @@ static int psb_create_backlight_property(struct drm_device *dev) > return 0; > > backlight = drm_property_create_range(dev, 0, "backlight", 0, 100); > + if (!backlight) > + return -ENOMEM; > > dev_priv->backlight_property = backlight; > NAK. If we fail to create the backlight we are better off continuing than failing. The user just loses backlight control rather than having no display at all. If you check the callers you'll notice that the only caller doesn't even check the return code anyway so your patch is a no-op. If you are going to add error checking to anything with a patch please work back through the call chain and check the effect of the new error return - if any. A better patch I think would be to just eliminate the function and turn it into a tiny bit of inlined code. I'll send a patch to do that shortly. Alan
On Fri, Jan 29, 2016 at 12:46 PM, One Thousand Gnomes < gnomes@lxorguk.ukuu.org.uk> wrote: > On Thu, 28 Jan 2016 19:05:16 -0500 > Insu Yun <wuninsu@gmail.com> wrote: > > > Since drm_property_create_range can be failed in memory pressure, > > it needs to be handled. > > > > Signed-off-by: Insu Yun <wuninsu@gmail.com> > > --- > > drivers/gpu/drm/gma500/framebuffer.c | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/drivers/gpu/drm/gma500/framebuffer.c > b/drivers/gpu/drm/gma500/framebuffer.c > > index cb95765..31085e4 100644 > > --- a/drivers/gpu/drm/gma500/framebuffer.c > > +++ b/drivers/gpu/drm/gma500/framebuffer.c > > @@ -683,6 +683,8 @@ static int psb_create_backlight_property(struct > drm_device *dev) > > return 0; > > > > backlight = drm_property_create_range(dev, 0, "backlight", 0, 100); > > + if (!backlight) > > + return -ENOMEM; > > > > dev_priv->backlight_property = backlight; > > > > NAK. > > If we fail to create the backlight we are better off continuing than > failing. The user just loses backlight control rather than having no > display at all. > > If you check the callers you'll notice that the only caller doesn't even > check the return code anyway so your patch is a no-op. If you are going > to add error checking to anything with a patch please work back through > the call chain and check the effect of the new error return - if any. > > A better patch I think would be to just eliminate the function and turn > it into a tiny bit of inlined code. > > I'll send a patch to do that shortly. > Thanks > > Alan > > > >
diff --git a/drivers/gpu/drm/gma500/framebuffer.c b/drivers/gpu/drm/gma500/framebuffer.c index cb95765..31085e4 100644 --- a/drivers/gpu/drm/gma500/framebuffer.c +++ b/drivers/gpu/drm/gma500/framebuffer.c @@ -683,6 +683,8 @@ static int psb_create_backlight_property(struct drm_device *dev) return 0; backlight = drm_property_create_range(dev, 0, "backlight", 0, 100); + if (!backlight) + return -ENOMEM; dev_priv->backlight_property = backlight;
Since drm_property_create_range can be failed in memory pressure, it needs to be handled. Signed-off-by: Insu Yun <wuninsu@gmail.com> --- drivers/gpu/drm/gma500/framebuffer.c | 2 ++ 1 file changed, 2 insertions(+)