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

From: Stephen Rothwell
Date: Mon Jan 24 2022 - 22:17:10 EST


Hi all,

On Tue, 25 Jan 2022 13:55:46 +1100 Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> 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 <sfr@xxxxxxxxxxxxxxxx>
Date: Tue, 25 Jan 2022 13:45:26 +1100
Subject: [PATCH] hack for building with -Warray-bounds

Signed-off-by: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
---
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

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