| Message ID | 20220330120246.25580-6-xiam0nd.tong@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | fix missing break in list_or_each_entry | expand |
On Wed, Mar 30, 2022 at 2:03 PM Xiaomeng Tong <xiam0nd.tong@gmail.com> wrote: > > Instead of exiting the loop as expected when an entry is found, the > list_for_each_entry() continues until the traversal is complete. To > avoid potential executing 'ret = gma_backlight_init(dev);' repeatly, > add a break after the switch statement. > > Fixes: 5c49fd3aa0ab0 ("gma500: Add the core DRM files and headers") > Signed-off-by: Xiaomeng Tong <xiam0nd.tong@gmail.com> This is incorrect. If we always break on the first iteration we will only run gma_backlight_init() if the first connector is LVDS or MIPI. This might not be the case and gma_backlight_init() will never run. The other loops you have been looking at have an "if (xxx != yyy) continue;" statement at the top which skips all the unwanted entries but this loop does not. > --- > drivers/gpu/drm/gma500/psb_drv.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/gpu/drm/gma500/psb_drv.c b/drivers/gpu/drm/gma500/psb_drv.c > index 65cf1c79dd7c..d65a68811bf7 100644 > --- a/drivers/gpu/drm/gma500/psb_drv.c > +++ b/drivers/gpu/drm/gma500/psb_drv.c > @@ -398,6 +398,8 @@ static int psb_driver_load(struct drm_device *dev, unsigned long flags) > ret = gma_backlight_init(dev); > break; > } > + > + break; > } > > if (ret) > -- > 2.17.1 >
On Fri, 1 Apr 2022 12:10:48 +0200, Patrik Jakobsson wrote: > On Wed, Mar 30, 2022 at 2:03 PM Xiaomeng Tong <xiam0nd.tong@gmail.com> wrote: > > > > Instead of exiting the loop as expected when an entry is found, the > > list_for_each_entry() continues until the traversal is complete. To > > avoid potential executing 'ret = gma_backlight_init(dev);' repeatly, > > add a break after the switch statement. > > > > Fixes: 5c49fd3aa0ab0 ("gma500: Add the core DRM files and headers") > > Signed-off-by: Xiaomeng Tong <xiam0nd.tong@gmail.com> > > This is incorrect. If we always break on the first iteration we will > only run gma_backlight_init() if the first connector is LVDS or MIPI. > This might not be the case and gma_backlight_init() will never run. > The other loops you have been looking at have an "if (xxx != yyy) > continue;" statement at the top which skips all the unwanted entries > but this loop does not. > Yes, your are correct. But it still need to break the loop when found it. So it is better to add if(!ret) break; after the switch statment. I will resend another patch if it is necessary. > > --- > > drivers/gpu/drm/gma500/psb_drv.c | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/drivers/gpu/drm/gma500/psb_drv.c b/drivers/gpu/drm/gma500/psb_drv.c > > index 65cf1c79dd7c..d65a68811bf7 100644 > > --- a/drivers/gpu/drm/gma500/psb_drv.c > > +++ b/drivers/gpu/drm/gma500/psb_drv.c > > @@ -398,6 +398,8 @@ static int psb_driver_load(struct drm_device *dev, unsigned long flags) > > ret = gma_backlight_init(dev); > > break; > > } > > + > > + break; > > } > > > > if (ret) > > -- > > 2.17.1 > > -- Xiaomeng Tong
diff --git a/drivers/gpu/drm/gma500/psb_drv.c b/drivers/gpu/drm/gma500/psb_drv.c index 65cf1c79dd7c..d65a68811bf7 100644 --- a/drivers/gpu/drm/gma500/psb_drv.c +++ b/drivers/gpu/drm/gma500/psb_drv.c @@ -398,6 +398,8 @@ static int psb_driver_load(struct drm_device *dev, unsigned long flags) ret = gma_backlight_init(dev); break; } + + break; } if (ret)
Instead of exiting the loop as expected when an entry is found, the list_for_each_entry() continues until the traversal is complete. To avoid potential executing 'ret = gma_backlight_init(dev);' repeatly, add a break after the switch statement. Fixes: 5c49fd3aa0ab0 ("gma500: Add the core DRM files and headers") Signed-off-by: Xiaomeng Tong <xiam0nd.tong@gmail.com> --- drivers/gpu/drm/gma500/psb_drv.c | 2 ++ 1 file changed, 2 insertions(+)