Subject: Re: linux-next: build failure after merge of the kspp tree

From: Stephen Rothwell <[email-masked]>
Date: Tue, 25 Jan 2022 14:02:21 +1100

Hi all,

On Tue, 25 Jan 2022 13:55:46 +1100 Stephen Rothwell <[email-masked]> wrote:
>
> After merging the kspp tree, today's linux-next build (powerpc
> allyesconfig) failed like this:
> 
> drivers/gpu/drm/kmb/kmb_plane.c: In function 'kmb_plane_atomic_disable':
> drivers/gpu/drm/kmb/kmb_plane.c:165:34: error: array subscript 3 is above array bounds of 'struct layer_status[2]' [-Werror=array-bounds]
>   165 |                 kmb->plane_status[plane_id].ctrl = LCD_CTRL_GL2_ENABLE;
>       |                 ~~~~~~~~~~~~~~~~~^~~~~~~~~~
> In file included from drivers/gpu/drm/kmb/kmb_plane.c:17:
> drivers/gpu/drm/kmb/kmb_drv.h:61:41: note: while referencing 'plane_status'
>    61 |         struct layer_status             plane_status[KMB_MAX_PLANES];
>       |                                         ^~~~~~~~~~~~
> drivers/gpu/drm/kmb/kmb_plane.c:162:34: error: array subscript 2 is above array bounds of 'struct layer_status[2]' [-Werror=array-bounds]
>   162 |                 kmb->plane_status[plane_id].ctrl = LCD_CTRL_GL1_ENABLE;
>       |                 ~~~~~~~~~~~~~~~~~^~~~~~~~~~
> In file included from drivers/gpu/drm/kmb/kmb_plane.c:17:
> drivers/gpu/drm/kmb/kmb_drv.h:61:41: note: while referencing 'plane_status'
>    61 |         struct layer_status             plane_status[KMB_MAX_PLANES];
>       |                                         ^~~~~~~~~~~~
> 
> Exposed by commit
> 
>   4ba545781e20 ("Makefile: Enable -Warray-bounds")
> 
> Originally introduced by commmit
> 
>   7f7b96a8a0a1 ("drm/kmb: Add support for KeemBay Display")
> 
> Maybe should have been fixed by
> 
>   c026565fe9be ("drm/kmb: Enable alpha blended second plane")
> 
> I have applied the following hack for now.

Actually, this one:

From: Stephen Rothwell <[email-masked]>
Date: Tue, 25 Jan 2022 13:45:26 +1100
Subject: [PATCH] hack for building with -Warray-bounds

Signed-off-by: Stephen Rothwell <[email-masked]>
---
 drivers/gpu/drm/kmb/kmb_plane.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/kmb/kmb_plane.c b/drivers/gpu/drm/kmb/kmb_plane.c
index 00404ba4126d..b54197920712 100644
--- a/drivers/gpu/drm/kmb/kmb_plane.c
+++ b/drivers/gpu/drm/kmb/kmb_plane.c
@@ -158,12 +158,14 @@ static void kmb_plane_atomic_disable(struct drm_plane *plane,
 	case LAYER_1:
 		kmb->plane_status[plane_id].ctrl = LCD_CTRL_VL2_ENABLE;
 		break;
+#if 0
 	case LAYER_2:
 		kmb->plane_status[plane_id].ctrl = LCD_CTRL_GL1_ENABLE;
 		break;
 	case LAYER_3:
 		kmb->plane_status[plane_id].ctrl = LCD_CTRL_GL2_ENABLE;
 		break;
+#endif
 	}
 
 	kmb->plane_status[plane_id].disable = true;
-- 
2.34.1

-- 
Cheers,
Stephen Rothwell