[PATCH v3] drm/gma500: fix a potential repeat execution in psb_driver_load

[PATCH v3] drm/gma500: fix a potential repeat execution in psb_driver_load

[Xiaomeng Tong]

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,
goto outside the loop when found entry by replacing switch/case with
if statement.

Signed-off-by: Xiaomeng Tong <xiam0nd.tong@gmail.com>
---
changes since v2:
 - replace switch with if statement (Patrik Jakobsson)

changes since v1:
 - goto outside the loop (Xiaomeng Tong)

v2: https://lore.kernel.org/dri-devel/20220406113143.10699-1-xiam0nd.tong@gmail.com/
v1: https://lore.kernel.org/lkml/20220401115811.9656-1-xiam0nd.tong@gmail.com/
---
 drivers/gpu/drm/gma500/psb_drv.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/gma500/psb_drv.c b/drivers/gpu/drm/gma500/psb_drv.c
index 2aff54d505e2..85211ec16e52 100644
--- a/drivers/gpu/drm/gma500/psb_drv.c
+++ b/drivers/gpu/drm/gma500/psb_drv.c
@@ -396,9 +396,8 @@ static int psb_driver_load(struct drm_device *dev, unsigned long flags)
 	drm_for_each_connector_iter(connector, &conn_iter) {
 		gma_encoder = gma_attached_encoder(connector);
 
-		switch (gma_encoder->type) {
-		case INTEL_OUTPUT_LVDS:
-		case INTEL_OUTPUT_MIPI:
+		if (gma_encoder->type == INTEL_OUTPUT_LVDS ||
+			gma_encoder->type == INTEL_OUTPUT_MIPI) {
 			ret = gma_backlight_init(dev);
 			break;
 		}
-- 
2.17.1

Re: [PATCH v3] drm/gma500: fix a potential repeat execution in psb_driver_load

[Patrik Jakobsson]

On Wed, Apr 13, 2022 at 7:11 AM 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,
> goto outside the loop when found entry by replacing switch/case with
> if statement.
>
> Signed-off-by: Xiaomeng Tong <xiam0nd.tong@gmail.com>

Thanks for the patch. I've applied it to drm-misc-next.

I fixed up an indentation issue on the second line.

Cheers
Patrik

> ---
> changes since v2:
>  - replace switch with if statement (Patrik Jakobsson)
>
> changes since v1:
>  - goto outside the loop (Xiaomeng Tong)
>
> v2: https://lore.kernel.org/dri-devel/20220406113143.10699-1-xiam0nd.tong@gmail.com/
> v1: https://lore.kernel.org/lkml/20220401115811.9656-1-xiam0nd.tong@gmail.com/
> ---
>  drivers/gpu/drm/gma500/psb_drv.c | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/gma500/psb_drv.c b/drivers/gpu/drm/gma500/psb_drv.c
> index 2aff54d505e2..85211ec16e52 100644
> --- a/drivers/gpu/drm/gma500/psb_drv.c
> +++ b/drivers/gpu/drm/gma500/psb_drv.c
> @@ -396,9 +396,8 @@ static int psb_driver_load(struct drm_device *dev, unsigned long flags)
>         drm_for_each_connector_iter(connector, &conn_iter) {
>                 gma_encoder = gma_attached_encoder(connector);
>
> -               switch (gma_encoder->type) {
> -               case INTEL_OUTPUT_LVDS:
> -               case INTEL_OUTPUT_MIPI:
> +               if (gma_encoder->type == INTEL_OUTPUT_LVDS ||
> +                       gma_encoder->type == INTEL_OUTPUT_MIPI) {
>                         ret = gma_backlight_init(dev);
>                         break;
>                 }
> --
> 2.17.1
>