2018-03-26 13:31:23

by Kieran Bingham

Subject: [PATCH] media: vsp1: Fix BRx conditional path in WPF

When a BRx is provided by a pipeline, the WPF must determine the master
layer. Currently the condition to check this identifies pipe->bru ||
pipe->num_inputs > 1.

The code then moves on to dereference pipe->bru, thus the check fails
static analysers on the possibility that pipe->num_inputs could be
greater than 1 without pipe->bru being set.

The reality is that the pipeline must have a BRx to support more than
one input, thus this could never cause a fault - however it also
identifies that the num_inputs > 1 check is redundant.

Remove the redundant check - and always configure the master layer
appropriately when we have a BRx configured in our pipeline.

Fixes: 6134148f6098 ("v4l: vsp1: Add support for the BRS entity")
Cc: [email protected]

Suggested-by: Mauro Carvalho Chehab <[email protected]>
Signed-off-by: Kieran Bingham <[email protected]>
---
drivers/media/platform/vsp1/vsp1_wpf.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/media/platform/vsp1/vsp1_wpf.c b/drivers/media/platform/vsp1/vsp1_wpf.c
index f7f3b4b2c2de..8bd6b2f1af15 100644
--- a/drivers/media/platform/vsp1/vsp1_wpf.c
+++ b/drivers/media/platform/vsp1/vsp1_wpf.c
@@ -452,7 +452,7 @@ static void wpf_configure(struct vsp1_entity *entity,
: VI6_WPF_SRCRPF_RPF_ACT_SUB(input->entity.index);
}

- if (pipe->bru || pipe->num_inputs > 1)
+ if (pipe->bru)
srcrpf |= pipe->bru->type == VSP1_ENTITY_BRU
? VI6_WPF_SRCRPF_VIRACT_MST
: VI6_WPF_SRCRPF_VIRACT2_MST;
--
2.7.4

2018-03-26 13:41:17

by Kieran Bingham

Subject: Re: [PATCH] media: vsp1: Fix BRx conditional path in WPF

Sorry,

This should have been from my +renesas to support Renesas' statistics and
filtering of course.

On 26/03/18 14:29, Kieran Bingham wrote:
> When a BRx is provided by a pipeline, the WPF must determine the master
> layer. Currently the condition to check this identifies pipe->bru ||
> pipe->num_inputs > 1.
>
> The code then moves on to dereference pipe->bru, thus the check fails
> static analysers on the possibility that pipe->num_inputs could be
> greater than 1 without pipe->bru being set.
>
> The reality is that the pipeline must have a BRx to support more than
> one input, thus this could never cause a fault - however it also
> identifies that the num_inputs > 1 check is redundant.
>
> Remove the redundant check - and always configure the master layer
> appropriately when we have a BRx configured in our pipeline.
>
> Fixes: 6134148f6098 ("v4l: vsp1: Add support for the BRS entity")
> Cc: [email protected]
>
> Suggested-by: Mauro Carvalho Chehab <[email protected]>
> Signed-off-by: Kieran Bingham <[email protected]>

And thus:

Signed-off-by: Kieran Bingham <[email protected]>


> ---
> drivers/media/platform/vsp1/vsp1_wpf.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/media/platform/vsp1/vsp1_wpf.c b/drivers/media/platform/vsp1/vsp1_wpf.c
> index f7f3b4b2c2de..8bd6b2f1af15 100644
> --- a/drivers/media/platform/vsp1/vsp1_wpf.c
> +++ b/drivers/media/platform/vsp1/vsp1_wpf.c
> @@ -452,7 +452,7 @@ static void wpf_configure(struct vsp1_entity *entity,
> : VI6_WPF_SRCRPF_RPF_ACT_SUB(input->entity.index);
> }
>
> - if (pipe->bru || pipe->num_inputs > 1)
> + if (pipe->bru)
> srcrpf |= pipe->bru->type == VSP1_ENTITY_BRU
> ? VI6_WPF_SRCRPF_VIRACT_MST
> : VI6_WPF_SRCRPF_VIRACT2_MST;
>

2018-03-26 17:23:38

by Laurent Pinchart

Subject: Re: [PATCH] media: vsp1: Fix BRx conditional path in WPF

Hi Kieran,

Thank you for the patch.

On Monday, 26 March 2018 16:29:17 EEST Kieran Bingham wrote:
> When a BRx is provided by a pipeline, the WPF must determine the master
> layer. Currently the condition to check this identifies pipe->bru ||
> pipe->num_inputs > 1.
>
> The code then moves on to dereference pipe->bru, thus the check fails
> static analysers on the possibility that pipe->num_inputs could be
> greater than 1 without pipe->bru being set.
>
> The reality is that the pipeline must have a BRx to support more than
> one input, thus this could never cause a fault - however it also
> identifies that the num_inputs > 1 check is redundant.
>
> Remove the redundant check - and always configure the master layer
> appropriately when we have a BRx configured in our pipeline.
>
> Fixes: 6134148f6098 ("v4l: vsp1: Add support for the BRS entity")
> Cc: [email protected]
>
> Suggested-by: Mauro Carvalho Chehab <[email protected]>
> Signed-off-by: Kieran Bingham <[email protected]>

Looking at commit 5d0beeec59e303c76160ddd67fa73dcfc5d76de0 I think your patch
is correct.

Reviewed-by: Laurent Pinchart <[email protected]>

and taken in my tree.

> ---
> drivers/media/platform/vsp1/vsp1_wpf.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/media/platform/vsp1/vsp1_wpf.c
> b/drivers/media/platform/vsp1/vsp1_wpf.c index f7f3b4b2c2de..8bd6b2f1af15
> 100644
> --- a/drivers/media/platform/vsp1/vsp1_wpf.c
> +++ b/drivers/media/platform/vsp1/vsp1_wpf.c
> @@ -452,7 +452,7 @@ static void wpf_configure(struct vsp1_entity *entity,
> : VI6_WPF_SRCRPF_RPF_ACT_SUB(input->entity.index);
> }
>
> - if (pipe->bru || pipe->num_inputs > 1)
> + if (pipe->bru)
> srcrpf |= pipe->bru->type == VSP1_ENTITY_BRU
> ? VI6_WPF_SRCRPF_VIRACT_MST
> : VI6_WPF_SRCRPF_VIRACT2_MST;

--
Regards,

Laurent Pinchart