[Intel-gfx] [PATCH] drm/i915/icl: Fix VEBOX mismatch BUG_ON()

[Chris Wilson]

Quoting José Roberto de Souza (2019-03-26 23:02:23)
> GT VEBOX DISABLE is only 4 bits wide but it was using a 8 bits wide
> mask, the remaning reserved bits is set to 0 causing 4 more
> nonexistent VEBOX engines being detected as enabled, triggering the
> BUG_ON() because of mismatch between vebox_mask and newly added
> VEBOX_MASK().
> 
> [   64.081621] [drm:intel_device_info_init_mmio [i915]] vdbox enable: 0005, instances: 0005
> [   64.081763] [drm:intel_device_info_init_mmio [i915]] vebox enable: 00f1, instances: 0001
> [   64.081825] intel_device_info_init_mmio:925 GEM_BUG_ON(vebox_mask != ({ unsigned int first__ = (VECS0); unsigned int count__ = (2); ((&(dev_priv)->__info)->engine_mask & (((~0UL) - (1UL << (first__)) + 1) & (~0UL >> (64 - 1 - (first__ + count__ - 1))))) >> first__; }))
> [   64.082047] ------------[ cut here ]------------
> [   64.082054] kernel BUG at drivers/gpu/drm/i915/intel_device_info.c:925!
> 
> BSpec: 20680
> Fixes: 9511cb6481af ("drm/i915: Adding missing '; ' to ENGINE_INSTANCES")
> Fixes: 26376a7e74d2 ("drm/i915/icl: Check for fused-off VDBOX and VEBOX instances")

Shooting the messenger, the fixes would be the incorrect
VEBOX_DISABLE_MASK would it not?
-Chris