Re: [PATCH] drm/amdgpu: clear set_q_mode_offs when VM changed

[Christian König]

Am 02.04.24 um 08:37 schrieb ZhenGuo Yin:
[Why]
set_q_mode_offs don't get cleared after GPU reset, nexting SET_Q_MODE
packet to init shadow memory will be skiped, hence there has a page fault.
[How]
VM flush is needed after GPU reset, clear set_q_mode_offs when
emitting VM flush.

Fixes: 8dad9c062355 ("drm/amdgpu: workaround to avoid SET_Q_MODE packets v2")
Signed-off-by: ZhenGuo Yin <zhenguo....@amd.com>

Good catch, yeah it probably doesn't make much sense to execute this 
after a VM flush.

Reviewed-by: Christian König <christian.koe...@amd.com>

---
  drivers/gpu/drm/amd/amdgpu/gfx_v11_0.c | 1 +
  1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v11_0.c 
b/drivers/gpu/drm/amd/amdgpu/gfx_v11_0.c
index 7a906318e451..c11c6299711e 100644
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v11_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v11_0.c
@@ -5465,6 +5465,7 @@ static void gfx_v11_0_ring_emit_vm_flush(struct 
amdgpu_ring *ring,
        /* Make sure that we can't skip the SET_Q_MODE packets when the VM
         * changed in any way.
         */
+       ring->set_q_mode_offs = 0;
        ring->set_q_mode_ptr = NULL;
  }