[Intel-gfx] [PATCH] drm/i915: Check for fused or unused pipes

[Dhinakaran Pandiyan]

On Friday, December 15, 2017 9:59:02 AM PST Mika Kahola wrote:
> In case of fused or unused pipes, return early with a warning when reading
> information for encoder.
> 
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=103206
> Reported-by: Thomas Gleixner <tglx at linutronix.de>
> Signed-off-by: Jani Nikula <jani.nikula at intel.com>
> Signed-off-by: Mika Kahola <mika.kahola at intel.com>
> ---
>  drivers/gpu/drm/i915/intel_audio.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_audio.c
> b/drivers/gpu/drm/i915/intel_audio.c index f1502a0..522d54f 100644
> --- a/drivers/gpu/drm/i915/intel_audio.c
> +++ b/drivers/gpu/drm/i915/intel_audio.c
> @@ -779,7 +779,7 @@ static struct intel_encoder *get_saved_enc(struct
> drm_i915_private *dev_priv, {
>  	struct intel_encoder *encoder;
> 
> -	if (WARN_ON(pipe >= INTEL_INFO(dev_priv)->num_pipes))
> +	if (WARN_ON(pipe >= ARRAY_SIZE(dev_priv->av_enc_map)))
>  		return NULL;

I think we should remove the WARN_ON() and just return NULL. The error return 
and the debug message we print in the caller is good enough IMO. 

> 
>  	/* MST */