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X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 30 Oct 2025 22:42:19.8061 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: d39d856b-5eab-4231-532d-08de180595b8 X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=43083d15-7273-40c1-b7db-39efd9ccc17a;Ip=[216.228.117.160];Helo=[mail.nvidia.com] X-MS-Exchange-CrossTenant-AuthSource: MWH0EPF000A6730.namprd04.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS5PPFF2923D4C1 On Mon, Oct 20, 2025 at 03:43:52PM -0700, Jacob Pan wrote: > @@ -785,10 +748,33 @@ static int arm_smmu_cmdq_issue_cmdlist(struct arm_smmu_device *smmu, > do { > u64 old; > > + queue_poll_init(smmu, &qp); > while (!queue_has_space(&llq, n + sync)) { > + unsigned long iflags; > + > local_irq_restore(flags); > - if (arm_smmu_cmdq_poll_until_not_full(smmu, cmdq, &llq)) > - dev_err_ratelimited(smmu->dev, "CMDQ timeout\n"); > + /* > + * Try to update our copy of cons by grabbing exclusive cmdq access. If > + * that fails, spin until somebody else updates it for us. > + */ > + if (arm_smmu_cmdq_exclusive_trylock_irqsave(cmdq, iflags)) { > + WRITE_ONCE(cmdq->q.llq.cons, readl_relaxed(cmdq->q.cons_reg)); > + arm_smmu_cmdq_exclusive_unlock_irqrestore(cmdq, iflags); > + llq.val = READ_ONCE(cmdq->q.llq.val); > + local_irq_save(flags); I don't quite get the reason why it moves queue_poll_init() and add local_irq_save(). It's quite different than what the driver has, so it's nicer to explain in the commit message at least. I still feel that we could just replace the _until_not_full() with a _until_has_space()? Nicolin