[PATCH] drm/i915: Widen return value for reservation_object_wait_timeout_rcu to long.

[PATCH] drm/i915: Widen return value for reservation_object_wait_timeout_rcu to long.

[Maarten Lankhorst]

This fixes a spurious warning from an integer overflow on 64-bits systems.
The function may return MAX_SCHEDULE_TIMEOUT which gets truncated to -1.

Explicitly handling this by casting to lret fixes it.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reported-and-tested-by: Joseph Yasi <joe.yasi@gmail.com>
---
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index b59a2d87b20e..06ba2bb36ce2 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -13686,13 +13686,15 @@ intel_prepare_plane_fb(struct drm_plane *plane,
 
 	/* For framebuffer backed by dmabuf, wait for fence */
 	if (obj && obj->base.dma_buf) {
-		ret = reservation_object_wait_timeout_rcu(obj->base.dma_buf->resv,
+		long lret;
+
+		lret = reservation_object_wait_timeout_rcu(obj->base.dma_buf->resv,
 							  false, true,
 							  MAX_SCHEDULE_TIMEOUT);
-		if (ret == -ERESTARTSYS)
-			return ret;
+		if (lret == -ERESTARTSYS)
+			return lret;
 
-		WARN_ON(ret < 0);
+		WARN(lret < 0, "waiting returns %li\n", lret);
 	}
 
 	if (!obj) {

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Re: [PATCH] drm/i915: Widen return value for reservation_object_wait_timeout_rcu to long.

[Daniel Vetter]

On Tue, Dec 08, 2015 at 03:52:56PM +0100, Maarten Lankhorst wrote:
> This fixes a spurious warning from an integer overflow on 64-bits systems.
> The function may return MAX_SCHEDULE_TIMEOUT which gets truncated to -1.
> 
> Explicitly handling this by casting to lret fixes it.
> Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
> Reported-and-tested-by: Joseph Yasi <joe.yasi@gmail.com>

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

> ---
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index b59a2d87b20e..06ba2bb36ce2 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -13686,13 +13686,15 @@ intel_prepare_plane_fb(struct drm_plane *plane,
>  
>  	/* For framebuffer backed by dmabuf, wait for fence */
>  	if (obj && obj->base.dma_buf) {
> -		ret = reservation_object_wait_timeout_rcu(obj->base.dma_buf->resv,
> +		long lret;
> +
> +		lret = reservation_object_wait_timeout_rcu(obj->base.dma_buf->resv,
>  							  false, true,
>  							  MAX_SCHEDULE_TIMEOUT);
> -		if (ret == -ERESTARTSYS)
> -			return ret;
> +		if (lret == -ERESTARTSYS)
> +			return lret;
>  
> -		WARN_ON(ret < 0);
> +		WARN(lret < 0, "waiting returns %li\n", lret);
>  	}
>  
>  	if (!obj) {
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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