drm/amdgpu: Fix cond_exec handling in amdgpu_ib_schedule()

The EXEC_COUNT field must be > 0.  In the gfx shadow
handling we always emit a cond_exec packet after the gfx_shadow
packet, but the EXEC_COUNT never gets patched.  This leads
to a hang when we try and reset queues on gfx11 APUs.

Fixes: c68cbbf ("drm/amdgpu: cleanup conditional execution")
Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4789
Reviewed-by: Jesse Zhang <Jesse.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit ba205ac)
Cc: stable@vger.kernel.org

Author: alexdeucher

drivers/gpu/drm/amd/amdgpu/amdgpu_ib.c

@@ -235,7 +235,7 @@ int amdgpu_ib_schedule(struct amdgpu_ring *ring, unsigned int num_ibs,
 
 	amdgpu_ring_ib_begin(ring);
 
-	if (ring->funcs->emit_gfx_shadow)
+	if (ring->funcs->emit_gfx_shadow && adev->gfx.cp_gfx_shadow)
 		amdgpu_ring_emit_gfx_shadow(ring, shadow_va, csa_va, gds_va,
 					    init_shadow, vmid);
 
@@ -291,7 +291,8 @@ int amdgpu_ib_schedule(struct amdgpu_ring *ring, unsigned int num_ibs,
 				       fence_flags | AMDGPU_FENCE_FLAG_64BIT);
 	}
 
-	if (ring->funcs->emit_gfx_shadow && ring->funcs->init_cond_exec) {
+	if (ring->funcs->emit_gfx_shadow && ring->funcs->init_cond_exec &&
+	    adev->gfx.cp_gfx_shadow) {
 		amdgpu_ring_emit_gfx_shadow(ring, 0, 0, 0, false, 0);
 		amdgpu_ring_init_cond_exec(ring, ring->cond_exe_gpu_addr);
 	}