From: Nicholas Kazlauskas nicholas.kazlauskas@amd.com

[ Upstream commit 791255ca9fbe38042cfd55df5deb116dc11fef18 ]

[Why] If the firmware wasn't reset by PSP or HW and is currently running then the firmware will hang or perform underfined behavior when we modify its firmware state underneath it.

[How] Reset DMCUB before setting up cache windows and performing HW init.

Reviewed-by: Aurabindo Jayamohanan Pillai Aurabindo.Pillai@amd.com Acked-by: Pavle Kotarac Pavle.Kotarac@amd.com Tested-by: Daniel Wheeler daniel.wheeler@amd.com Signed-off-by: Nicholas Kazlauskas nicholas.kazlauskas@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 5 +++++ 1 file changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c index fef13e93a99fd..bdc894bd66e31 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -900,6 +900,11 @@ static int dm_dmub_hw_init(struct amdgpu_device *adev) return 0; }

+ /* Reset DMCUB if it was previously running - before we overwrite its memory. */ + status = dmub_srv_hw_reset(dmub_srv); + if (status != DMUB_STATUS_OK) + DRM_WARN("Error resetting DMUB HW: %d\n", status); + hdr = (const struct dmcub_firmware_header_v1_0 *)dmub_fw->data;

fw_inst_const = dmub_fw->data +