SMU messages may use fewer arguments than the available argument registers, the previous code only wrote used registers and left the rest unchanged, so stale values from a prior message could persist.
Write all argument registers for each message and zero the unused tail to keep command arguments deterministic and avoid unintended carry-over. Signed-off-by: Yang Wang <[email protected]> --- drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c b/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c index 546e64e3ba9c..85e7a8b347f7 100644 --- a/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c +++ b/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c @@ -313,11 +313,15 @@ static void __smu_msg_v1_send(struct smu_msg_ctl *ctl, u16 index, { struct amdgpu_device *adev = ctl->smu->adev; struct smu_msg_config *cfg = &ctl->config; + u32 arg; int i; WREG32(cfg->resp_reg, 0); - for (i = 0; i < args->num_args; i++) - WREG32(cfg->arg_regs[i], args->args[i]); + for (i = 0; i < ctl->config.num_arg_regs; i++) { + /* NOTE: Clear unused argument registers to avoid stale values. */ + arg = i < args->num_args ? args->args[i] : 0; + WREG32(cfg->arg_regs[i], arg); + } WREG32(cfg->msg_reg, index); } -- 2.47.3
