[Intel-gfx] [PATCH] drm/i915: Add missing ring_mask to Pineview

[Joonas Lahtinen]

On pe, 2016-07-29 at 00:45 +0100, Chris Wilson wrote:
> It appears that we never told Pineview it has a RENDER_RING. This was
> all fine until we started using the ring_mask for determining all the
> available rings to initialise for legacy ringbuffer submission in commit
> 88d2ba2e95c8 ("drm/i915: Unify engine init loop"). Though really it is a
> latent bug since the ring_mask inception in commit 73ae478cdf6a
> ("drm/i915: Replace has_bsd/blt/vebox with a mask").
> 
> To prevent similar mishaps in future, add a WARN_ON() if we find
> ourselves with a device without any rings.
> 
> Fixes: 73ae478cdf6a ("drm/i915: Replace has_bsd/blt/vebox with a mask")
> Fixes: 88d2ba2e95c8 ("drm/i915: Unify engine init loop")
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
> Cc: Ben Widawsky <ben at bwidawsk.net>
> ---
>  drivers/gpu/drm/i915/i915_pci.c        | 1 +
>  drivers/gpu/drm/i915/intel_engine_cs.c | 1 +
>  2 files changed, 2 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/i915_pci.c b/drivers/gpu/drm/i915/i915_pci.c
> index 949c01686a66..2587b1bd41f4 100644
> --- a/drivers/gpu/drm/i915/i915_pci.c
> +++ b/drivers/gpu/drm/i915/i915_pci.c
> @@ -173,6 +173,7 @@ static const struct intel_device_info intel_pineview_info = {
>  	.gen = 3, .is_g33 = 1, .is_pineview = 1, .is_mobile = 1, .num_pipes = 2,
>  	.need_gfx_hws = 1, .has_hotplug = 1,
>  	.has_overlay = 1,
> +	.ring_mask = RENDER_RING,
>  	GEN_DEFAULT_PIPEOFFSETS,
>  	CURSOR_OFFSETS,
>  };
> diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c b/drivers/gpu/drm/i915/intel_engine_cs.c
> index 31d43dfa7469..e6422aac2919 100644
> --- a/drivers/gpu/drm/i915/intel_engine_cs.c
> +++ b/drivers/gpu/drm/i915/intel_engine_cs.c
> @@ -117,6 +117,7 @@ int intel_engines_init(struct drm_device *dev)
>  	unsigned int i;
>  	int ret;
>  
> +	WARN_ON(INTEL_INFO(dev_priv)->ring_mask == 0);

Reviewed-by: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>

>  	WARN_ON(INTEL_INFO(dev_priv)->ring_mask &
>  		GENMASK(sizeof(mask) * BITS_PER_BYTE - 1, I915_NUM_ENGINES));
>  
-- 
Joonas Lahtinen
Open Source Technology Center
Intel Corporation