[PATCH] drm: Suppress user controlled spam for invalid drm_wait_vblank_ioctl

[Daniel Vetter]

On Tue, Sep 04, 2018 at 12:57:19PM +0100, Chris Wilson wrote:
> The ioctl arguments are under control of the user and as such we should
> resist any temptation to flood the kernel logs with their errors.
> Relegate the DRM_ERROR to a DRM_DEBUG so the user has to opt into
> hearing of their own mistakes. (One day we will have a small ringbuffer
> attached to the task, so that the concerned process can inspect its own
> debug info for EINVAL without them being hitting syslog at all.)
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Daniel Vetter <daniel.vetter at ffwll.ch>

igt for this would be lovely. Either way Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>

> ---
>  drivers/gpu/drm/drm_vblank.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c
> index 28cdcf76b6f9..a528920542ca 100644
> --- a/drivers/gpu/drm/drm_vblank.c
> +++ b/drivers/gpu/drm/drm_vblank.c
> @@ -1541,7 +1541,7 @@ int drm_wait_vblank_ioctl(struct drm_device *dev, void *data,
>  	if (vblwait->request.type &
>  	    ~(_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
>  	      _DRM_VBLANK_HIGH_CRTC_MASK)) {
> -		DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n",
> +		DRM_DEBUG("Unsupported type value 0x%x, supported mask 0x%x\n",
>  			  vblwait->request.type,
>  			  (_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK |
>  			   _DRM_VBLANK_HIGH_CRTC_MASK));
> -- 
> 2.19.0.rc1
> 

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