Commit d5b2a3a4 authored by Chris Wilson's avatar Chris Wilson
Browse files

drm/i915: Check for a second VCS engine more carefully 



To use the legacy BSD selector, you must have a second VCS engine, or
else the ABI simply maps the request for another engine onto VCS0.
However, we only checked a single VCS1 location and overlooking the
possibility of a sparse VCS set being mapped to the dense ABI.

v2: num_vcs_engines() turns out to be reusable and futureproof it so we
never have to worry about this silly bit of ABI again!

Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: default avatarJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190809123153.20574-1-chris@chris-wilson.co.uk
parent 6cd34b10

drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c

+7 −1
Original line number Original line Diff line number Diff line
@@ -2102,6 +2102,12 @@ static int eb_submit(struct i915_execbuffer *eb) 
	return 0;

	return 0;

}

}





static int num_vcs_engines(const struct drm_i915_private *i915)

{

	return hweight64(INTEL_INFO(i915)->engine_mask &

			 GENMASK_ULL(VCS0 + I915_MAX_VCS - 1, VCS0));

}



/*

/*

 * Find one BSD ring to dispatch the corresponding BSD command.

 * Find one BSD ring to dispatch the corresponding BSD command.

 * The engine index is returned.

 * The engine index is returned.
@@ -2200,7 +2206,7 @@ eb_select_legacy_ring(struct i915_execbuffer *eb, 
		return -1;

		return -1;

	}

	}





	if (user_ring_id == I915_EXEC_BSD && HAS_ENGINE(i915, VCS1)) {

	if (user_ring_id == I915_EXEC_BSD && num_vcs_engines(i915) > 1) {

		unsigned int bsd_idx = args->flags & I915_EXEC_BSD_MASK;

		unsigned int bsd_idx = args->flags & I915_EXEC_BSD_MASK;





		if (bsd_idx == I915_EXEC_BSD_DEFAULT) {

		if (bsd_idx == I915_EXEC_BSD_DEFAULT) {