On Tue, Jul 02, 2024 at 12:47:14PM -0700, Nicolin Chen wrote: > @@ -345,6 +345,11 @@ static void arm_smmu_cmdq_build_sync_cmd(u64 *cmd, struct arm_smmu_device *smmu, > FIELD_PREP(CMDQ_SYNC_0_MSH, ARM_SMMU_SH_ISH) | > FIELD_PREP(CMDQ_SYNC_0_MSIATTR, ARM_SMMU_MEMATTR_OIWB); > > + if (cmdq->type == TEGRA241_VCMDQ) { > + cmd[0] |= FIELD_PREP(CMDQ_SYNC_0_CS, CMDQ_SYNC_0_CS_NONE); > + return; > + } > + > if (!(smmu->options & ARM_SMMU_OPT_MSIPOLL)) { > cmd[0] |= FIELD_PREP(CMDQ_SYNC_0_CS, CMDQ_SYNC_0_CS_SEV); > return; > @@ -690,7 +695,8 @@ static int arm_smmu_cmdq_poll_until_sync(struct arm_smmu_device *smmu, > struct arm_smmu_cmdq *cmdq, > struct arm_smmu_ll_queue *llq) > { > - if (smmu->options & ARM_SMMU_OPT_MSIPOLL) > + if (smmu->options & ARM_SMMU_OPT_MSIPOLL && > + cmdq->type != TEGRA241_VCMDQ) { > return __arm_smmu_cmdq_poll_until_msi(smmu, cmdq, llq); > > -------------------------------------------------------------- > > Would you prefer this one? I feel CMDQ_QUIRK_SYNC_CS_NONE_ONLY > is more general looking though.. And we would need some additional lines of comments for the two pieces above, explaining why TEGRA241_VCMDQ type needs the first one while bypasses the second one. Again, it feels even worse :( Thanks Nicolin